diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/ietfyang/IetfYangFileTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/ietfyang/IetfYangFileTest.java
new file mode 100644
index 0000000..0f0a514
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/ietfyang/IetfYangFileTest.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.ietfyang;
+
+import org.apache.maven.plugin.MojoExecutionException;
+import org.junit.Test;
+import org.onosproject.yangutils.linker.impl.YangLinkerManager;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.plugin.manager.YangUtilManager;
+import org.onosproject.yangutils.translator.tojava.utils.YangPluginConfig;
+import org.onosproject.yangutils.utils.io.impl.YangFileScanner;
+
+import java.io.IOException;
+
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Test cases for testing IETF YANG files.
+ */
+public class IetfYangFileTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+    private final YangUtilManager utilManager = new YangUtilManager();
+    private final YangLinkerManager yangLinkerManager = new YangLinkerManager();
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     * Reference: https://datatracker.ietf.org/doc/draft-zha-l3sm-l3vpn-onos-deployment
+     */
+    @Test
+    public void l3vpnserviceyang()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/ietfyang/l3vpnservice";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/ietfyang/l3vpnservice/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/ietfyang/");
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterFileLinkingTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterFileLinkingTest.java
new file mode 100644
index 0000000..fd7b8ad
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterFileLinkingTest.java
@@ -0,0 +1,741 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.linker;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.ListIterator;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangUses;
+import org.onosproject.yangutils.datamodel.utils.ResolvableStatus;
+import org.onosproject.yangutils.linker.impl.YangLinkerManager;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
+import org.onosproject.yangutils.plugin.manager.YangUtilManager;
+import org.onosproject.yangutils.translator.tojava.utils.YangPluginConfig;
+import org.onosproject.yangutils.utils.io.impl.YangFileScanner;
+
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.datamodel.YangNodeType.MODULE_NODE;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.RESOLVED;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Test cases for testing inter file linking.
+ */
+public class InterFileLinkingTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+    private final YangUtilManager utilManager = new YangUtilManager();
+    private final YangLinkerManager yangLinkerManager = new YangLinkerManager();
+
+    /**
+     * Checks inter file type linking.
+     */
+    @Test
+    public void processInterFileTypeLinking()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfiletype";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) refNode.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks inter file uses linking.
+     */
+    @Test
+    public void processInterFileUsesLinking()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfileuses";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((selfNode instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the sibling of module's child.
+        assertThat((refNode.getChild() instanceof YangGrouping), is(true));
+
+        YangGrouping grouping = (YangGrouping) refNode.getChild();
+        leafIterator = grouping.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether uses is module's child.
+        assertThat((yangNode.getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) yangNode.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        leafIterator = yangNode.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under module.
+//        assertThat(leafInfo.getName(), is("hello"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+    }
+
+    /**
+     * Checks inter file type linking with include list.
+     */
+    @Test
+    public void processInterFileTypeLinkingWithIncludeList()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfiletypewithinclude";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Carry out linking of sub module with module.
+        yangLinkerManager.linkSubModulesToParentModule(utilManager.getYangFileInfoSet());
+
+        // Add reference to include list.
+        yangLinkerManager.addRefToYangFilesIncludeList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) refNode.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks inter file uses linking with include list.
+     */
+    @Test
+    public void processInterFileUsesLinkingWithInclude()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfileuseswithinclude";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Carry out linking of sub module with module.
+        yangLinkerManager.linkSubModulesToParentModule(utilManager.getYangFileInfoSet());
+
+        // Add reference to include list.
+        yangLinkerManager.addRefToYangFilesIncludeList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((selfNode instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the sibling of module's child.
+        assertThat((refNode.getChild() instanceof YangGrouping), is(true));
+
+        YangGrouping grouping = (YangGrouping) refNode.getChild();
+        leafIterator = grouping.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether uses is module's child.
+        assertThat((yangNode.getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) yangNode.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        leafIterator = yangNode.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under module.
+//        assertThat(leafInfo.getName(), is("hello"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+    }
+
+    /**
+     * Checks inter file type linking with revision.
+     */
+    @Test
+    public void processInterFileTypeLinkingWithRevision()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfiletypewithrevision";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) refNode.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks inter file type linking with revision in name.
+     */
+    @Test
+    public void processInterFileTypeLinkingWithRevisionInName()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfiletypewithrevisioninname";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        if (yangFileInfo.getRootNode().getName().equals("module1")) {
+            selfNode = yangFileInfo.getRootNode();
+            refNode = yangFileInfoIterator.next().getRootNode();
+        } else {
+            refNode = yangFileInfo.getRootNode();
+            selfNode = yangFileInfoIterator.next().getRootNode();
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("module1"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) refNode.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks hierarchical inter file type linking.
+     */
+    @Test
+    public void processHierarchicalInterFileTypeLinking()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/hierarchicalinterfiletype";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode1 = null;
+        YangNode refNode2 = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        for (YangFileInfo yangFile : utilManager.getYangFileInfoSet()) {
+            if (yangFile.getRootNode().getName().equals("ietf-network-topology")) {
+                selfNode = yangFile.getRootNode();
+            } else if (yangFile.getRootNode().getName().equals("ietf-network")) {
+                refNode1 = yangFile.getRootNode();
+            } else {
+                refNode2 = yangFile.getRootNode();
+            }
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("ietf-network-topology"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("source-node"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("node-id"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) refNode1.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void processHierarchicalIntraWithInterFileTypeLinking()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/hierarchicalintrawithinterfiletype";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+
+        YangNode refNode1 = null;
+        YangNode selfNode = null;
+
+        // Create YANG node set
+        yangLinkerManager.createYangNodeSet(utilManager.getYangFileInfoSet());
+
+        // Add references to import list.
+        yangLinkerManager.addRefToYangFilesImportList(utilManager.getYangFileInfoSet());
+
+        // Carry out inter-file linking.
+        yangLinkerManager.processInterFileLinking(utilManager.getYangFileInfoSet());
+
+        for (YangFileInfo yangFile : utilManager.getYangFileInfoSet()) {
+            if (yangFile.getRootNode().getName().equals("ietf-network")) {
+                selfNode = yangFile.getRootNode();
+            } else if (yangFile.getRootNode().getName().equals("ietf-inet-types")) {
+                refNode1 = yangFile.getRootNode();
+            }
+        }
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(selfNode instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(selfNode.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) selfNode;
+        assertThat(yangNode.getName(), is("ietf-network"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("node-ref"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("node-id"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) selfNode.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void interFileWithUsesReferringType()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfilewithusesreferringtype";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/interfilewithusesreferringtype/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/interfilewithusesreferringtype/");
+
+    }
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void file1UsesFile2TypeDefFile3Type()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/file1UsesFile2TypeDefFile3Type";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/file1UsesFile2TypeDefFile3Type/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/file1UsesFile2TypeDefFile3Type/");
+
+    }
+
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void interFileIetf()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/interfileietf";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/interfileietf/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/interfileietf/");
+
+    }
+
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void usesInContainer()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/usesInContainer";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/usesInContainer/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/usesInContainer/");
+
+    }
+
+
+    /**
+     * Checks hierarchical intra with inter file type linking.
+     */
+    @Test
+    public void groupingNodeSameAsModule()
+            throws IOException, ParserException, MojoExecutionException {
+
+        String searchDir = "src/test/resources/groupingNodeSameAsModule";
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(searchDir));
+        utilManager.parseYangFileInfoSet();
+        utilManager.resolveDependenciesUsingLinker();
+
+        String userDir = System.getProperty("user.dir");
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/groupingNodeSameAsModule/");
+
+        utilManager.translateToJava(utilManager.getYangFileInfoSet(), yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/groupingNodeSameAsModule/");
+
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterJarLinkingTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterJarLinkingTest.java
new file mode 100644
index 0000000..39b03fe
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/InterJarLinkingTest.java
@@ -0,0 +1,217 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.linker;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+import org.apache.maven.plugin.MojoExecutionException;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.plugin.manager.YangFileInfo;
+import org.onosproject.yangutils.plugin.manager.YangUtilManager;
+import org.onosproject.yangutils.utils.io.impl.YangFileScanner;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.RESOLVED;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deSerializeDataModel;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.parseJarFile;
+
+/**
+ * Unit test case for inter-jar linker.
+ */
+public class InterJarLinkingTest {
+
+    private final YangUtilManager utilManager = new YangUtilManager();
+
+    private static final String TARGET = "target/interJarFileLinking";
+    private static final String SEARCH_DIR_FOR_YANG_FILES = "src/test/resources/interJarFileLinking/yangFiles";
+    private static final String SEARCH_DIR_FOR_SINGLE_JAR_FILES = "src/test/resources/interJarFileLinking/"
+            + "jarFiles/single";
+    private static final String SEARCH_DIR_FOR_MULTI_JAR_FILES = "src/test/resources/interJarFileLinking/"
+            + "jarFiles/multi";
+
+    /**
+     * Unit test case for a single jar dependency.
+     *
+     * @throws IOException when fails to do IO operations
+     * @throws MojoExecutionException when fails to do mojo operations
+     */
+    @Test
+    public void processSingleJarLinking()
+            throws IOException, MojoExecutionException {
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(SEARCH_DIR_FOR_YANG_FILES));
+
+        int size1 = utilManager.getYangFileInfoSet().size();
+
+        for (String file : getListOfTestJar(SEARCH_DIR_FOR_SINGLE_JAR_FILES)) {
+            addInterJarRootNodes(file);
+        }
+
+        utilManager.parseYangFileInfoSet();
+
+        utilManager.resolveDependenciesUsingLinker();
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        int size2 = utilManager.getYangFileInfoSet().size();
+        assertThat(true, is(size1 != size2));
+        assertThat(true, is(yangFileInfo.getRootNode().getName().equals("port-pair")));
+
+        deleteDirectory(TARGET);
+
+    }
+
+    /**
+     * Unit test case for a multiple jar dependency.
+     *
+     * @throws IOException when fails to do IO operations
+     * @throws MojoExecutionException when fails to do mojo operations
+     */
+    @Test
+    public void processMultipleJarLinking()
+            throws IOException, MojoExecutionException {
+        utilManager.createYangFileInfoSet(YangFileScanner.getYangFiles(SEARCH_DIR_FOR_YANG_FILES));
+
+        int size1 = utilManager.getYangFileInfoSet().size();
+
+        for (String file : getListOfTestJar(SEARCH_DIR_FOR_MULTI_JAR_FILES)) {
+            addInterJarRootNodes(file);
+        }
+
+        utilManager.parseYangFileInfoSet();
+
+        utilManager.resolveDependenciesUsingLinker();
+
+        Iterator<YangFileInfo> yangFileInfoIterator = utilManager.getYangFileInfoSet().iterator();
+
+        YangFileInfo yangFileInfo = yangFileInfoIterator.next();
+
+        int size2 = utilManager.getYangFileInfoSet().size();
+        assertThat(true, is(size1 != size2));
+        assertThat(true, is(yangFileInfo.getRootNode().getName().equals("port-pair")));
+
+        yangFileInfo = yangFileInfoIterator.next();
+        assertThat(true, is(yangFileInfo.getRootNode().getName().equals("flow-classifier")));
+
+        /*
+         * grouping flow-classifier {
+         *      container flow-classifier {
+         *           leaf id {
+         *                type flow-classifier-id;
+         *           }
+         *
+         *           leaf tenant-id {
+         *                type port-pair:tenant-id;
+         *           }
+         *           .
+         *           .
+         *           .
+         *
+         */
+
+        YangNode node = yangFileInfo.getRootNode();
+        node = node.getChild();
+        while (node != null) {
+            if (node instanceof YangGrouping) {
+                break;
+            }
+            node = node.getNextSibling();
+        }
+
+        node = node.getChild();
+        ListIterator<YangLeaf> leafIterator = ((YangContainer) node).getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("id"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("flow-classifier-id"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("tenant-id"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(true, is(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef()
+                .getName().equals("tenant-id")));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        deleteDirectory(TARGET);
+    }
+
+    /**
+     * Returns list of test jar files.
+     *
+     * @param searchdir search directory
+     * @return list of test jar files
+     */
+    private List<String> getListOfTestJar(String searchdir) {
+        List<String> jarFiles = new ArrayList<>();
+
+        File directory = new File(searchdir + "/");
+        File[] files = directory.listFiles();
+
+        for (File file : files) {
+            jarFiles.add(file.toString());
+        }
+
+        return jarFiles;
+    }
+
+    /**
+     * Adds data model nodes of jar to file info set.
+     *
+     * @param jarFile jar file name
+     * @throws IOException when fails to do IO operations
+     */
+    private void addInterJarRootNodes(String jarFile) throws IOException {
+        try {
+            List<YangNode> interJarResolvedNodes = deSerializeDataModel(parseJarFile(jarFile, TARGET));
+
+            for (YangNode node : interJarResolvedNodes) {
+                YangFileInfo dependentFileInfo = new YangFileInfo();
+                dependentFileInfo.setRootNode(node);
+                dependentFileInfo.setForTranslator(false);
+                dependentFileInfo.setYangFileName(node.getName());
+                utilManager.getYangFileInfoSet().add(dependentFileInfo);
+            }
+        } catch (IOException e) {
+            throw new IOException("failed to resolve in interjar scenario.");
+        }
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileTypeLinkingTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileTypeLinkingTest.java
new file mode 100644
index 0000000..9fba40e
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileTypeLinkingTest.java
@@ -0,0 +1,565 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.linker;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.linker.exceptions.LinkerException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.BINARY;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.INT32;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.datamodel.YangNodeType.MODULE_NODE;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.INTRA_FILE_RESOLVED;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.RESOLVED;
+
+/**
+ * Test cases for testing "type" intra file linking.
+ */
+public class IntraFileTypeLinkingTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks self resolution when typedef and leaf using type are siblings.
+     */
+    @Test
+    public void processSelfResolutionWhenTypeAndTypedefAtRootLevel()
+            throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SelfResolutionWhenTypeAndTypedefAtRootLevel.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when typedef and leaf using type are at different
+     * level where typedef is at the root.
+     */
+    @Test
+    public void processSelfFileLinkingTypedefAtRootTypeTwoLevelInHierarchy()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingTypedefAtRootTypeTwoLevelInHierarchy.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when typedef and leaf using type are at different
+     * level where typedef is at the root and defined after parent holder
+     * of type.
+     */
+    @Test
+    public void processSelfFileLinkingTypedefAtRootIsAfterContainerHavingType()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingTypedefAtRootIsAfterContainerHavingType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild().getNextSibling()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when typedef and leaf using type are at different
+     * level where typedef is at the level of root+1 and defined after parent
+     * holder of type.
+     */
+    @Test
+    public void processSelfFileLinkingTypedefAtMiddleLevelAfterParentHolder()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingTypedefAtMiddleLevelAfterParentHolder.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangContainer.getChild().getNextSibling()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when typedef hierarchical references are present.
+     */
+    @Test
+    public void processSelfFileLinkingWithTypdefHierarchicalReference()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingWithTypdefHierarchicalReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("FirstClass"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangList.getChild()));
+        assertThat(leafInfo.getDataType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangTypeDef typeDef1 = (YangTypeDef) yangList.getChild();
+
+        assertThat(((YangDerivedInfo<?>) typeDef1.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangContainer.getChild().getNextSibling()));
+        assertThat(typeDef1.getTypeDefBaseType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangTypeDef typeDef2 = (YangTypeDef) yangContainer.getChild().getNextSibling();
+
+        assertThat(((YangDerivedInfo<?>) typeDef2.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+        assertThat(typeDef2.getTypeDefBaseType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(INT32));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when typedef hierarchical references are present
+     * with last type is unresolved.
+     */
+    @Test
+    public void processSelfFileLinkingWithTypdefHierarchicalRefUnresolved()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingWithTypdefHierarchicalRefUnresolved.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("FirstClass"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangList.getChild()));
+        assertThat(leafInfo.getDataType().getResolvableStatus(),
+                is(INTRA_FILE_RESOLVED));
+
+        YangTypeDef typeDef1 = (YangTypeDef) yangList.getChild();
+
+        assertThat(((YangDerivedInfo<?>) typeDef1.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangContainer.getChild().getNextSibling()));
+        assertThat(typeDef1.getTypeDefBaseType().getResolvableStatus(),
+                is(INTRA_FILE_RESOLVED));
+
+        YangTypeDef typeDef2 = (YangTypeDef) yangContainer.getChild().getNextSibling();
+
+        assertThat(((YangDerivedInfo<?>) typeDef2.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+        assertThat(typeDef2.getTypeDefBaseType().getResolvableStatus(),
+                is(INTRA_FILE_RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(nullValue()));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when type uses prefix of self module.
+     */
+    @Test
+    public void processSelfFileLinkingWithTypeWithSelfModulePrefix()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingWithTypeWithSelfModulePrefix.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("FirstClass"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangList.getChild()));
+        assertThat(leafInfo.getDataType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangTypeDef typeDef1 = (YangTypeDef) yangList.getChild();
+
+        assertThat(((YangDerivedInfo<?>) typeDef1.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangContainer.getChild().getNextSibling()));
+        assertThat(typeDef1.getTypeDefBaseType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangTypeDef typeDef2 = (YangTypeDef) yangContainer.getChild().getNextSibling();
+
+        assertThat(((YangDerivedInfo<?>) typeDef2.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+        assertThat(typeDef2.getTypeDefBaseType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(INT32));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Checks self resolution when some type uses prefix of self module
+     * some uses external prefix.
+     */
+    @Test
+    public void processSelfFileLinkingWithTypeWithSelfAndExternalPrefixMix()
+            throws IOException, ParserException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingWithTypeWithSelfAndExternalPrefixMix.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("FirstClass"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) yangList.getChild()));
+        assertThat(leafInfo.getDataType().getResolvableStatus(),
+                is(INTRA_FILE_RESOLVED));
+
+        YangTypeDef typeDef1 = (YangTypeDef) yangList.getChild();
+
+        YangTypeDef typeDef2 = (YangTypeDef) yangContainer.getChild().getNextSibling();
+
+        assertThat(((YangDerivedInfo<?>) typeDef2.getTypeDefBaseType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+        assertThat(typeDef2.getTypeDefBaseType().getResolvableStatus(),
+                is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(nullValue()));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+
+    /**
+     * Check self resolution when type referred typedef is not available in
+     * file.
+     */
+    @Test(expected = LinkerException.class)
+    public void processSelfResolutionWhenTypeReferredTypedefNotDefined()
+            throws IOException, LinkerException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfResolutionWhenTypeReferredTypedefNotDefined.yang");
+    }
+
+    /**
+     * Checks self resolution when typedef and leaf using type are at different
+     * level where typedef is is not an ancestor of type.
+     */
+    @Test(expected = LinkerException.class)
+    public void processSelfFileLinkingTypedefNotFound()
+            throws IOException, LinkerException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SelfFileLinkingTypedefNotFound.yang");
+    }
+
+    /**
+     * Checks hierarchical self resolution with self resolution failure scenario.
+     */
+    @Test(expected = LinkerException.class)
+    public void processSelfFileLinkingWithHierarchicalTypeFailureScenario()
+            throws IOException, LinkerException {
+
+        YangNode node =
+                manager.getDataModel("src/test/resources/SelfFileLinkingWithHierarchicalTypeFailureScenario.yang");
+    }
+
+    /**
+     * Checks self resolution when typedef and leaf using type are siblings for binary type.
+     */
+    @Test
+    public void processSelfResolutionWhenTypeAndTypedefAtRootLevelForBinary()
+            throws IOException, ParserException {
+
+        YangNode node
+                = manager.getDataModel("src/test/resources/SelfResolutionWhenTypeAndTypedefAtRootLevelForBinary.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("ospf"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("typedef14"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("type14"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(BINARY));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(nullValue()));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileUsesLinkingTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileUsesLinkingTest.java
new file mode 100644
index 0000000..e960d62
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/IntraFileUsesLinkingTest.java
@@ -0,0 +1,756 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.linker;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangUses;
+import org.onosproject.yangutils.datamodel.utils.ResolvableStatus;
+import org.onosproject.yangutils.linker.exceptions.LinkerException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing uses intra file linking.
+ */
+public class IntraFileUsesLinkingTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks self resolution when grouping and uses are siblings.
+     * Grouping followed by uses.
+     */
+    @Test
+    public void processSelfResolutionWhenUsesAndGroupingAtRootLevel()
+            throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SelfResolutionWhenUsesAndGroupingAtRootLevel.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the sibling of module's child.
+        assertThat((yangNode.getChild().getNextSibling() instanceof YangGrouping), is(true));
+
+        YangGrouping grouping = (YangGrouping) yangNode.getChild().getNextSibling();
+        leafIterator = grouping.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether uses is module's child.
+        assertThat((yangNode.getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) yangNode.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        leafIterator = yangNode.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under module.
+//        assertThat(leafInfo.getName(), is("hello"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+    }
+
+    /**
+     * Checks self resolution when grouping and uses are siblings.
+     * Grouping has a child node.
+     */
+    @Test
+    public void processSelfResolutionWhenUsesAndGroupingAtRootLevelGroupingWithChild()
+            throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel(
+                "src/test/resources/SelfResolutionWhenUsesAndGroupingAtRootLevelGroupingWithChild.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the sibling of module's child.
+        assertThat((yangNode.getChild().getNextSibling() instanceof YangGrouping), is(true));
+
+        YangGrouping grouping = (YangGrouping) yangNode.getChild().getNextSibling();
+        leafIterator = grouping.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("treat"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether container is the child of grouping.
+        assertThat((grouping.getChild() instanceof YangContainer), is(true));
+        YangContainer container = (YangContainer) grouping.getChild();
+
+        // Check whether the container name is set correctly which is under grouping.
+        assertThat(container.getName(), is("test"));
+
+        leafIterator = container.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under container which is under grouping.
+        assertThat(leafInfo.getName(), is("leaf2"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether uses is module's child.
+        assertThat((yangNode.getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) yangNode.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        leafIterator = yangNode.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under module.
+//        assertThat(leafInfo.getName(), is("treat"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+//        // Check whether container is the child of module.
+//        assertThat((grouping.getNextSibling() instanceof YangContainer), is(true));
+//        container = (YangContainer) grouping.getNextSibling();
+//
+//        // Check whether the container name is set correctly which is under module.
+//        assertThat(container.getName(), is("test"));
+//
+//        leafIterator = container.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under container which is under module.
+//        assertThat(leafInfo.getName(), is("leaf2"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+    }
+
+    /**
+     * Checks self resolution when grouping in rpc and uses in output of the same rpc.
+     * Uses is followed by grouping.
+     */
+    @Test
+    public void processSelfResolutionGroupingInRpcAndUsesInOutput()
+            throws IOException, ParserException {
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfResolutionGroupingInRpcAndUsesInOutput.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the child of rpc.
+        assertThat((yangNode.getChild().getChild() instanceof YangGrouping), is(true));
+        YangGrouping grouping = (YangGrouping) yangNode.getChild().getChild();
+
+        // Check whether the grouping name is set correctly.
+        assertThat(grouping.getName(), is("hello"));
+
+        // Check whether list is the child of grouping.
+        assertThat((grouping.getChild() instanceof YangList), is(true));
+        YangList yangListNode = (YangList) grouping.getChild();
+
+        // Check whether the list name is set correctly.
+        assertThat(yangListNode.getName(), is("valid"));
+
+        leafIterator = yangListNode.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under list which is under grouping.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+
+        // Check whether uses is input's child.
+        assertThat((yangNode.getChild().getChild().getNextSibling().getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) yangNode.getChild().getChild().getNextSibling().getChild();
+
+        // Check whether uses get resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        // Check whether list is the sibling of uses which has been deep copied from grouping.
+//        assertThat((yangNode.getChild().getChild().getNextSibling().getChild().getNextSibling() instanceof YangList),
+//                is(true));
+//        YangList yangList = (YangList) yangNode.getChild().getChild().getNextSibling().getChild().getNextSibling();
+//
+//        // Check whether the list name is set correctly.
+//        assertThat(yangList.getName(), is("valid"));
+//
+//        leafIterator = yangList.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under list which is deep copied.
+//        assertThat(leafInfo.getName(), is("invalid-interval"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+//        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+//        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+//
+//        // Check whether uses is output's child.
+//        assertThat((yangNode.getChild().getChild().getNextSibling().getNextSibling().getChild() instanceof YangUses),
+//                is(true));
+//        YangUses usesInOuput = (YangUses) yangNode.getChild().getChild().getNextSibling().getNextSibling().getChild();
+//
+//        // Check whether uses get resolved.
+//        assertThat(usesInOuput.getResolvableStatus(),
+//                is(ResolvableStatus.RESOLVED));
+//
+//        // Check whether list is the sibling of uses which has been deep copied from grouping.
+//        assertThat((yangNode.getChild().getChild().getNextSibling().getChild().getNextSibling() instanceof YangList),
+//                is(true));
+//
+//        YangList yangListInOutput = (YangList) yangNode.getChild().getChild().getNextSibling().getNextSibling()
+//                .getChild().getNextSibling();
+//
+//        // Check whether the list name is set correctly.
+//        assertThat(yangListInOutput.getName(), is("valid"));
+//
+//        leafIterator = yangListInOutput.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under list which is deep copied.
+//        assertThat(leafInfo.getName(), is("invalid-interval"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+//        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+//        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks the failure scenario when uses is referring to its own grouping directly.
+     */
+    @Test
+    public void processSelfResolutionGroupingReferencingItselfFailureScenerio()
+            throws IOException {
+
+        thrown.expect(LinkerException.class);
+        thrown.expectMessage(
+                "YANG file error: Duplicate input identifier detected, same as leaf \"zip-code\"");
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfResolutionGroupingReferencingItselfFailureScenerio.yang");
+
+    }
+
+    /**
+     * Checks the when multiple uses are present and are referred to the grouping at different levels.
+     */
+    @Test
+    public void processSelfResolutionGroupingWithMultipleUses()
+            throws IOException, ParserException {
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfResolutionGroupingWithMultipleUses.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the child of container.
+        assertThat((yangNode.getChild().getChild() instanceof YangGrouping), is(true));
+        YangGrouping grouping = (YangGrouping) yangNode.getChild().getChild();
+
+        // Check whether the grouping name is set correctly.
+        assertThat(grouping.getName(), is("endpoint"));
+
+        // Check whether uses is endpoint-grouping's child.
+        assertThat((grouping.getChild() instanceof YangUses), is(true));
+        YangUses firstUses = (YangUses) grouping.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(firstUses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether container is the sibling of uses.
+        assertThat((firstUses.getNextSibling() instanceof YangContainer), is(true));
+        YangContainer yangContainer = (YangContainer) firstUses.getNextSibling();
+
+        // Check whether the container name is set correctly.
+        assertThat(yangContainer.getName(), is("design"));
+
+//        leafIterator = yangContainer.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under design-container.
+//        assertThat(leafInfo.getName(), is("ink"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("int32"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+
+        // Check whether uses is design-container's child.
+        assertThat((yangContainer.getChild() instanceof YangUses), is(true));
+        YangUses secondUses = (YangUses) yangContainer.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(secondUses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether container is the sibling of uses.
+        assertThat((secondUses.getNextSibling() instanceof YangContainer), is(true));
+        YangContainer yangContainer2 = (YangContainer) secondUses.getNextSibling();
+        assertThat(yangContainer2.getName(), is("correct"));
+
+        leafIterator = yangContainer2.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under correct-container.
+        assertThat(leafInfo.getName(), is("newone"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether uses is correct container's child.
+        assertThat((yangContainer2.getChild() instanceof YangUses), is(true));
+        YangUses thirdUses = (YangUses) yangContainer2.getChild();
+
+        // Check whether uses get resolved.
+        assertThat(thirdUses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+//        // Check whether container is the sibling of uses.
+//        assertThat((thirdUses.getNextSibling() instanceof YangContainer), is(true));
+//
+//        YangContainer yangContainer3 = (YangContainer) thirdUses.getNextSibling();
+//        assertThat(yangContainer3.getName(), is("value"));
+//
+//        leafIterator = yangContainer3.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under container
+//        // which has been deep copied from grouping.
+//        assertThat(leafInfo.getName(), is("zip-code"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+//
+//        // Check whether uses is the sibling of container-design.
+//        assertThat((yangContainer.getNextSibling() instanceof YangUses), is(true));
+//        YangUses fourthUses = (YangUses) yangContainer.getNextSibling();
+//
+//        // Check whether uses get resolved.
+//        assertThat(fourthUses.getResolvableStatus(),
+//                is(ResolvableStatus.RESOLVED));
+//
+//        // Check whether uses is the sibling of previous uses.
+//        assertThat((fourthUses.getNextSibling() instanceof YangUses), is(true));
+//        YangUses fifthUses = (YangUses) fourthUses.getNextSibling();
+//
+//        // Check whether uses get resolved.
+//        assertThat(fifthUses.getResolvableStatus(),
+//                is(ResolvableStatus.RESOLVED));
+//
+//        // Check whether list is the sibling of uses.
+//        assertThat((fifthUses.getNextSibling() instanceof YangList), is(true));
+//        YangList yangList = (YangList) fifthUses.getNextSibling();
+//        assertThat(yangList.getName(), is("valid"));
+//
+//        leafIterator = yangList.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under list which has been deep copied from grouping.
+//        assertThat(leafInfo.getName(), is("invalid-interval"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+//        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+//        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+//
+//        // Check whether typedef is the sibling of list.
+//        assertThat((yangList.getNextSibling() instanceof YangTypeDef), is(true));
+//        YangTypeDef yangTypeDef = (YangTypeDef) yangList.getNextSibling();
+//        assertThat(yangTypeDef.getName(), is("my-type"));
+//
+//        leafIterator = grouping.getListOfLeaf().listIterator();
+//        leafInfo = leafIterator.next();
+//
+//        // Check whether the information in the leaf is correct under grouping.
+//        assertThat(leafInfo.getName(), is("zip-code"));
+//        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+//        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+//
+//        // Check whether uses is endpoint-grouping's sibling.
+//        assertThat((grouping.getNextSibling() instanceof YangUses), is(true));
+//        YangUses endpointUses = (YangUses) grouping.getNextSibling();
+//
+//        // Check whether uses get resolved.
+//        assertThat(endpointUses.getResolvableStatus(),
+//                is(ResolvableStatus.RESOLVED));
+//
+//        assertThat((endpointUses.getNextSibling().getNextSibling().getNextSibling().getNextSibling().getNextSibling()
+//                .getNextSibling() instanceof YangUses), is(true));
+//
+//        YangUses yangUsesInEndpoint = (YangUses) endpointUses.getNextSibling().getNextSibling().getNextSibling()
+//                .getNextSibling().getNextSibling().getNextSibling();
+//        assertThat(yangUsesInEndpoint.getResolvableStatus(),
+//                is(ResolvableStatus.RESOLVED));
+//
+//        assertThat((yangUsesInEndpoint.getNextSibling() instanceof YangContainer), is(true));
+//        YangContainer yangContainerInEndPoint = (YangContainer) yangUsesInEndpoint.getNextSibling();
+//
+//        assertThat(yangContainerInEndPoint.getName(), is("design"));
+    }
+
+    /**
+     * Checks the failure scenario when uses is present under the same node many times.
+     */
+    @Test
+    public void processSelfResolutionGroupingHavingSameUsesManyTimes()
+            throws IOException, ParserException {
+
+        thrown.expect(ParserException.class);
+        thrown.expectMessage(
+                "YANG file error: Duplicate input identifier detected, same as uses \"failure\"");
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfResolutionGroupingHavingSameUsesManyTimes.yang");
+    }
+
+    /**
+     * Checks the rpc having both typedef and grouping.
+     * It also checks that the grouping under different nodes will not give any problem in resolving uses.
+     */
+    @Test
+    public void processSelfResolutionRpcWithOneTypedefAndTwoGroupingUnderDifferentNode()
+            throws IOException, ParserException {
+
+        YangNode node = manager
+                .getDataModel(
+                        "src/test/resources/SelfResolutionRpcWithOneTypedefAndTwoGroupingUnderDifferentNode.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+
+        // Check whether grouping is the child of input.
+        assertThat((yangNode.getChild().getChild().getChild() instanceof YangGrouping), is(true));
+        YangGrouping groupingUnderInput = (YangGrouping) yangNode.getChild().getChild().getChild();
+
+        // Check whether the grouping name is set correctly.
+        assertThat(groupingUnderInput.getName(), is("creative"));
+
+        leafIterator = groupingUnderInput.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("carry"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+        // Check whether grouping is the child of output.
+        assertThat((yangNode.getChild().getChild().getNextSibling().getChild() instanceof YangGrouping), is(true));
+        YangGrouping grouping = (YangGrouping) yangNode.getChild().getChild().getNextSibling().getChild();
+        assertThat(grouping.getName(), is("creative"));
+
+        // Check whether typedef is the sibling of grouping.
+        assertThat((grouping.getNextSibling() instanceof YangTypeDef), is(true));
+
+        YangTypeDef typedef = (YangTypeDef) grouping.getNextSibling();
+        assertThat(typedef.getName(), is("my-type"));
+
+        // Check whether uses is the sibling of typedef.
+        assertThat((typedef.getNextSibling() instanceof YangUses), is(true));
+
+        // Check whether uses get resolved.
+        YangUses uses = (YangUses) typedef.getNextSibling();
+        assertThat(uses.getName(), is("creative"));
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+    }
+
+    /**
+     * Checks the failure scenario when uses is cannot resolve its grouping.
+     */
+    @Test
+    public void processSelfResolutionNestedGroupingWithUnresolvedUses()
+            throws IOException, LinkerException {
+
+        thrown.expect(LinkerException.class);
+        thrown.expectMessage(
+                "YANG file error: Unable to find base grouping for given uses");
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfResolutionNestedGroupingWithUnresolvedUses.yang");
+    }
+
+    /**
+     * Checks self resolution when typedef hierarchical references are present
+     * with last type is unresolved.
+     */
+    @Test
+    public void processSelfFileLinkingWithGroupingHierarchicalRefUnresolved()
+            throws IOException, ParserException {
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfFileLinkingWithGroupingHierarchicalRefUnresolved.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether container is the sibling of grouping.
+        assertThat((yangNode.getChild().getNextSibling() instanceof YangContainer), is(true));
+        YangContainer containerWithUses = (YangContainer) yangNode.getChild().getNextSibling();
+        assertThat(containerWithUses.getName(), is("test"));
+
+        // Check whether uses is the child of container.
+        assertThat((containerWithUses.getChild() instanceof YangUses), is(true));
+        YangUses uses = (YangUses) containerWithUses.getChild();
+        assertThat(uses.getName(), is("create"));
+
+        // Check whether uses is getting resolved.
+        assertThat(uses.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether grouping is the child of module.
+        assertThat((yangNode.getChild() instanceof YangGrouping), is(true));
+        YangGrouping groupingWithUses = (YangGrouping) yangNode.getChild();
+        assertThat(groupingWithUses.getName(), is("create"));
+
+        // Check whether uses with prefix from from other file, is the child of grouping.
+        assertThat((groupingWithUses.getChild() instanceof YangUses), is(true));
+        YangUses uses1 = (YangUses) groupingWithUses.getChild();
+        assertThat(uses1.getName(), is("valid"));
+
+        // Check whether this uses is getting intra-file-resolved.
+        assertThat(uses1.getResolvableStatus(),
+                is(ResolvableStatus.INTRA_FILE_RESOLVED));
+    }
+
+    /**
+     * Checks self resolution when uses has prefix of self module.
+     */
+    @Test
+    public void processSelfFileLinkingWithGroupingWithSelfModulePrefix()
+            throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SelfFileLinkingWithGroupingWithSelfModulePrefix.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether container is the sibling of grouping.
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        // Check whether list is the child of container.
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        // Check whether uses is the child of list.
+        assertThat((yangList.getChild() instanceof YangUses), is(true));
+        YangUses yangUses1 = (YangUses) yangList.getChild();
+        assertThat(yangUses1.getName(), is("FirstClass"));
+
+        // Check whether uses is getting resolved.
+        assertThat(yangUses1.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether grouping is the sibling of uses.
+        YangGrouping yangGrouping1 = (YangGrouping) yangUses1.getNextSibling();
+        assertThat(yangGrouping1.getName(), is("FirstClass"));
+
+        // Check whether uses is the child of grouping.
+        YangUses yangUses2 = (YangUses) yangGrouping1.getChild();
+        assertThat(yangUses2.getName(), is("PassingClass"));
+
+        // Check the uses gets resolved.
+        assertThat(yangUses2.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether grouping is the sibling of list.
+        YangGrouping yangGrouping2 = (YangGrouping) yangList.getNextSibling();
+        assertThat(yangGrouping2.getName(), is("PassingClass"));
+
+        // Check uses is the child of that grouping which has prefix of the same module.
+        YangUses yangUses3 = (YangUses) yangGrouping2.getChild();
+        assertThat(yangUses3.getName(), is("Percentage"));
+
+        // Check uses is getting resolved.
+        assertThat(yangUses3.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check grouping is the child of module.
+        YangGrouping yangGrouping3 = (YangGrouping) node.getChild();
+
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+        leafIterator = yangGrouping3.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+
+    }
+
+    /**
+     * Checks self resolution when some type uses prefix of self module
+     * some uses external prefix.
+     */
+    @Test
+    public void processSelfFileLinkingWithGroupingWithSelfAndExternalPrefixMix()
+            throws IOException, ParserException {
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/SelfFileLinkingWithGroupingWithSelfAndExternalPrefixMix.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether container is the sibling of grouping.
+        YangContainer yangContainer = (YangContainer) node.getChild().getNextSibling();
+
+        // Check whether list is the child of container.
+        YangList yangList = (YangList) yangContainer.getChild();
+
+        // Check whether uses is the child of list.
+        assertThat((yangList.getChild() instanceof YangUses), is(true));
+        YangUses yangUses1 = (YangUses) yangList.getChild();
+        assertThat(yangUses1.getName(), is("FirstClass"));
+
+        // Check whether uses is getting resolved.
+        assertThat(yangUses1.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check whether grouping is the sibling of uses.
+        YangGrouping yangGrouping1 = (YangGrouping) yangUses1.getNextSibling();
+        assertThat(yangGrouping1.getName(), is("FirstClass"));
+
+        // Check whether uses is the child of grouping which has prefix from other module.
+        YangUses yangUses2 = (YangUses) yangGrouping1.getChild();
+        assertThat(yangUses2.getName(), is("PassingClass"));
+
+        // Check whether uses gets intra-file-resolved.
+        assertThat(yangUses2.getResolvableStatus(),
+                is(ResolvableStatus.INTRA_FILE_RESOLVED));
+
+        // Check whether grouping is the sibling of list.
+        YangGrouping yangGrouping2 = (YangGrouping) yangList.getNextSibling();
+        assertThat(yangGrouping2.getName(), is("PassingClass"));
+
+        // Check uses is the child of that grouping which has prefix of the same module.
+        YangUses yangUses3 = (YangUses) yangGrouping2.getChild();
+        assertThat(yangUses3.getName(), is("Percentage"));
+
+        // Check uses is getting resolved.
+        assertThat(yangUses3.getResolvableStatus(),
+                is(ResolvableStatus.RESOLVED));
+
+        // Check grouping is the child of module.
+        YangGrouping yangGrouping3 = (YangGrouping) node.getChild();
+        ListIterator<YangLeaf> leafIterator;
+        YangLeaf leafInfo;
+        leafIterator = yangGrouping3.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+
+        // Check whether the information in the leaf is correct under grouping.
+        assertThat(leafInfo.getName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/RestrictionResolutionTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/RestrictionResolutionTest.java
new file mode 100644
index 0000000..211f924
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/linker/RestrictionResolutionTest.java
@@ -0,0 +1,835 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.linker;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangPatternRestriction;
+import org.onosproject.yangutils.datamodel.YangRangeInterval;
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.utils.builtindatatype.YangInt32;
+import org.onosproject.yangutils.datamodel.utils.builtindatatype.YangUint64;
+import org.onosproject.yangutils.linker.exceptions.LinkerException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNull.notNullValue;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.INT32;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.datamodel.YangNodeType.MODULE_NODE;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.RESOLVED;
+
+/**
+ * Test cases for testing restriction resolution.
+ */
+public final class RestrictionResolutionTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks length restriction in typedef.
+     */
+    @Test
+    public void processLengthRestrictionInTypedef()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthRestrictionInTypedef.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks length restriction in referred type.
+     */
+    @Test
+    public void processLengthRestrictionInRefType()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthRestrictionInRefType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks length restriction in typedef and in type with stricter value.
+     */
+    @Test
+    public void processLengthRestrictionInTypedefAndTypeValid()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthRestrictionInTypedefAndTypeValid.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval1.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval1.getEndValue()).getValue(), is(BigInteger.valueOf(20)));
+
+        YangRangeInterval rangeInterval2 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval2.getStartValue()).getValue(), is(BigInteger.valueOf(201)));
+        assertThat(((YangUint64) rangeInterval2.getEndValue()).getValue(), is(BigInteger.valueOf(300)));
+    }
+
+    /**
+     * Checks length restriction in typedef and in type with not stricter value.
+     */
+    @Test(expected = LinkerException.class)
+    public void processLengthRestrictionInTypedefAndTypeInValid()
+            throws IOException, DataModelException {
+        YangNode node = manager.getDataModel("src/test/resources/LengthRestrictionInTypedefAndTypeInValid.yang");
+    }
+
+    /**
+     * Checks range restriction in typedef.
+     */
+    @Test
+    public void processRangeRestrictionInTypedef()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInTypedef.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(INT32));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) derivedInfo.getResolvedExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval1.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval1.getEndValue()).getValue(), is(4));
+
+        YangRangeInterval rangeInterval2 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval2.getStartValue()).getValue(), is(10));
+        assertThat(((YangInt32) rangeInterval2.getEndValue()).getValue(), is(20));
+    }
+
+    /**
+     * Checks range restriction in referred type.
+     */
+    @Test
+    public void processRangeRestrictionInRefType()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInRefType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(INT32));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) derivedInfo.getResolvedExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval1.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval1.getEndValue()).getValue(), is(4));
+
+        YangRangeInterval rangeInterval2 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval2.getStartValue()).getValue(), is(10));
+        assertThat(((YangInt32) rangeInterval2.getEndValue()).getValue(), is(20));
+    }
+
+    /**
+     * Checks range restriction in typedef and stricter in referred type.
+     */
+    @Test
+    public void processRangeRestrictionInRefTypeAndTypedefValid()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInRefTypeAndTypedefValid.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(INT32));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) derivedInfo.getResolvedExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval1.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval1.getEndValue()).getValue(), is(4));
+
+        YangRangeInterval rangeInterval2 = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval2.getStartValue()).getValue(), is(10));
+        assertThat(((YangInt32) rangeInterval2.getEndValue()).getValue(), is(20));
+    }
+
+    /**
+     * Checks range restriction in typedef and not stricter in referred type.
+     */
+    @Test(expected = LinkerException.class)
+    public void processRangeRestrictionInRefTypeAndTypedefInValid()
+            throws IOException, ParserException, DataModelException {
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInRefTypeAndTypedefInValid.yang");
+    }
+
+    /**
+     * Checks range restriction for string.
+     */
+    @Test(expected = ParserException.class)
+    public void processRangeRestrictionInString()
+            throws IOException, ParserException, DataModelException {
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInString.yang");
+    }
+
+    /**
+     * Checks range restriction for string in referred type.
+     */
+    @Test(expected = LinkerException.class)
+    public void processRangeRestrictionInStringInRefType()
+            throws IOException, DataModelException {
+        YangNode node = manager.getDataModel("src/test/resources/RangeRestrictionInStringInRefType.yang");
+    }
+
+    /**
+     * Checks pattern restriction in typedef.
+     */
+    @Test
+    public void processPatternRestrictionInTypedef()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternRestrictionInTypedef.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(nullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks pattern restriction in referred type.
+     */
+    @Test
+    public void processPatternRestrictionInRefType()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternRestrictionInRefType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(notNullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks pattern restriction in referred type and typedef.
+     */
+    @Test
+    public void processPatternRestrictionInRefTypeAndTypedef()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternRestrictionInRefTypeAndTypedef.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(notNullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-zA-Z]"));
+
+        String pattern2 = patternListIterator.next();
+
+        assertThat(pattern2, is("[0-9]"));
+    }
+
+    /**
+     * Checks multiple pattern restriction in referred type and typedef.
+     */
+    @Test
+    public void processMultiplePatternRestriction()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternRestrictionInRefTypeAndTypedef.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(notNullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-z]"));
+
+        String pattern2 = patternListIterator.next();
+
+        assertThat(pattern2, is("[A-Z]"));
+
+        String pattern3 = patternListIterator.next();
+
+        assertThat(pattern3, is("[0-9]"));
+
+        String pattern4 = patternListIterator.next();
+
+        assertThat(pattern4, is("[\\n]"));
+    }
+
+    /**
+     * Checks multiple pattern and length restriction in referred type and
+     * typedef.
+     */
+    @Test
+    public void processMultiplePatternAndLengthRestriction()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternAndLengthRestriction.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(notNullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+
+        // Check for pattern restriction.
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-z]"));
+
+        String pattern2 = patternListIterator.next();
+
+        assertThat(pattern2, is("[A-Z]"));
+
+        String pattern3 = patternListIterator.next();
+
+        assertThat(pattern3, is("[0-9]"));
+
+        String pattern4 = patternListIterator.next();
+
+        assertThat(pattern4, is("[\\n]"));
+
+        // Check for length restriction.
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval1.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval1.getEndValue()).getValue(), is(BigInteger.valueOf(20)));
+
+        YangRangeInterval rangeInterval2 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval2.getStartValue()).getValue(), is(BigInteger.valueOf(201)));
+        assertThat(((YangUint64) rangeInterval2.getEndValue()).getValue(), is(BigInteger.valueOf(300)));
+    }
+
+    /**
+     * Checks multiple pattern and length restriction in referred type and
+     * typedef.
+     */
+    @Test
+    public void processMultiplePatternAndLengthRestrictionValid()
+            throws IOException, ParserException, DataModelException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternAndLengthRestrictionValid.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(DERIVED));
+
+        assertThat(((YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo()).getReferredTypeDef(),
+                is((YangTypeDef) node.getChild()));
+
+        assertThat(leafInfo.getDataType().getResolvableStatus(), is(RESOLVED));
+
+        YangDerivedInfo<?> derivedInfo = (YangDerivedInfo<?>) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        // Check for the effective built-in type.
+        assertThat(derivedInfo.getEffectiveBuiltInType(), is(STRING));
+
+        // Check for the restriction.
+        assertThat(derivedInfo.getLengthRestrictionString(), is(notNullValue()));
+        assertThat(derivedInfo.getRangeRestrictionString(), is(nullValue()));
+        assertThat(derivedInfo.getPatternRestriction(), is(notNullValue()));
+        assertThat(derivedInfo.getResolvedExtendedInfo(), is(notNullValue()));
+
+        // Check for the restriction value.
+        YangStringRestriction stringRestriction = (YangStringRestriction) derivedInfo.getResolvedExtendedInfo();
+
+        // Check for pattern restriction.
+        YangPatternRestriction patternRestriction = stringRestriction.getPatternRestriction();
+        ListIterator<String> patternListIterator = patternRestriction.getPatternList().listIterator();
+        String pattern1 = patternListIterator.next();
+
+        assertThat(pattern1, is("[a-z]"));
+
+        String pattern2 = patternListIterator.next();
+
+        assertThat(pattern2, is("[A-Z]"));
+
+        String pattern3 = patternListIterator.next();
+
+        assertThat(pattern3, is("[0-9]"));
+
+        String pattern4 = patternListIterator.next();
+
+        assertThat(pattern4, is("[\\n]"));
+
+        // Check for length restriction.
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval1 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval1.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval1.getEndValue()).getValue(), is(BigInteger.valueOf(20)));
+
+        YangRangeInterval rangeInterval2 = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval2.getStartValue()).getValue(), is(BigInteger.valueOf(100)));
+        assertThat(((YangUint64) rangeInterval2.getEndValue()).getValue(),
+                is(new BigInteger("18446744073709551615")));
+    }
+
+    /**
+     * Checks multiple pattern and length restriction in referred type and
+     * typedef invalid scenario.
+     */
+    @Test(expected = LinkerException.class)
+    public void processMultiplePatternAndLengthRestrictionInValid()
+            throws IOException, DataModelException {
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternAndLengthRestrictionInValid.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/CustomExceptionMatcher.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/CustomExceptionMatcher.java
new file mode 100644
index 0000000..44d0c67
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/CustomExceptionMatcher.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl;
+
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeMatcher;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+
+/**
+ * ExpectedException framework can use the Hamcrest matcher's to test
+ * custom/extended exceptions. This class extends the type safe matcher to
+ * define the custom exception matcher.
+ */
+public final class CustomExceptionMatcher extends TypeSafeMatcher<ParserException> {
+
+    private int actualLine;
+    private final int expectedLine;
+    private int actualCharPosition;
+    private final int expectedCharPosition;
+
+    /**
+     * Customized exception matcher to match error location.
+     *
+     * @param line error line
+     * @param charPosition error character position
+     * @return customized exception matcher to match error location
+     */
+    public static CustomExceptionMatcher errorLocation(int line, int charPosition) {
+        return new CustomExceptionMatcher(line, charPosition);
+    }
+
+    private CustomExceptionMatcher(int expectedLine, int expectedCharPosition) {
+        this.expectedLine = expectedLine;
+        this.expectedCharPosition = expectedCharPosition;
+    }
+
+    @Override
+    protected boolean matchesSafely(final ParserException exception) {
+        actualLine = exception.getLineNumber();
+        actualCharPosition = exception.getCharPositionInLine();
+        return ((actualLine == expectedLine) && (actualCharPosition == expectedCharPosition));
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText(" Error reported location ")
+                .appendText("Line " + actualLine + ", " + "CharPosition " + actualCharPosition)
+                .appendText(" instead of expected ")
+                .appendText("Line " + expectedLine + ", " + "CharPosition " + expectedCharPosition);
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/TreeWalkListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/TreeWalkListenerTest.java
new file mode 100644
index 0000000..1056d98
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/TreeWalkListenerTest.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl;
+
+import java.io.IOException;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+
+/**
+ * Test cases for testing tree walk listener functionality.
+ */
+public class TreeWalkListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Checks whether exception is thrown for ordered statement.
+     */
+    @Test
+    public void processOrderedByStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"ordered-by\" is not supported in current version, please check wiki" +
+                " for YANG utils road map.");
+        manager.getDataModel("src/test/resources/OrderedByStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown for anyxml statement.
+     */
+    @Test
+    public void processAnyXmlStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"anyxml\" is not supported.");
+        manager.getDataModel("src/test/resources/AnyxmlStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when extra brace is added in the EOF.
+     */
+    @Test
+    public void processFileWithExtraBrace() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting <EOF>");
+        manager.getDataModel("src/test/resources/ProcessFileWithExtraBrace.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf is given after module ends.
+     */
+    @Test
+    public void processFileWithExtraLeaf() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaf' expecting <EOF>");
+        manager.getDataModel("src/test/resources/ProcessFileWithExtraLeaf.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when extra brace is added in between the EOF.
+     */
+    @Test
+    public void processFileWithExtraBraceInBetween() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'container' expecting <EOF>");
+        manager.getDataModel("src/test/resources/ProcessFileWithExtraBraceInBetween.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManagerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManagerTest.java
new file mode 100644
index 0000000..9b3effc
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManagerTest.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+
+/**
+ * Test case for testing YANG utils parser manager.
+ */
+public class YangUtilsParserManagerTest {
+
+    YangUtilsParserManager manager = new YangUtilsParserManager();
+    File file;
+    BufferedWriter out;
+
+    @Before
+    public void setUp() throws Exception {
+        file = new File("demo.yang");
+        out = new BufferedWriter(new FileWriter(file));
+    }
+    @After
+    public void tearDown() throws Exception {
+        file.delete();
+    }
+
+    /**
+     * This test case checks whether the null pointer exception is generated
+     * when the input YANG file is null.
+     */
+    @Test(expected = NullPointerException.class)
+    public void getDataModelNullFileTest() throws IOException, ParserException {
+        YangUtilsParserManager manager = new YangUtilsParserManager();
+        YangNode node = manager.getDataModel(null);
+    }
+
+    /**
+     * This test case checks whether the io exception is generated
+     * when the input YANG file is non existent.
+     */
+    @Test(expected = ParserException.class)
+    public void getDataModelNonExistentFileTest() throws IOException, ParserException {
+
+        YangUtilsParserManager manager = new YangUtilsParserManager();
+        YangNode node = manager.getDataModel("nonexistent.yang");
+    }
+
+    /**
+     * This test case checks if the input YANG file is correct no exception
+     * should be generated.
+     */
+    @Test
+    public void getDataModelCorrectFileTest() throws IOException, ParserException {
+
+        out.write("module ONOS {\n");
+        out.write("yang-version 1;\n");
+        out.write("namespace urn:ietf:params:xml:ns:yang:ietf-ospf;\n");
+        out.write("prefix On;\n");
+        out.write("}\n");
+        out.close();
+
+        YangNode node = manager.getDataModel("demo.yang");
+    }
+
+    /**
+     * This test case checks if the input YANG file with wrong YANG constructs
+     * than parser exception should be generated.
+     */
+    @Test(expected = ParserException.class)
+    public void getDataModelIncorrectFileTest() throws IOException, ParserException {
+
+        out.write("module ONOS {\n");
+        out.write("yang-version 1\n");
+        out.write("namespace urn:ietf:params:xml:ns:yang:ietf-ospf;\n");
+        out.write("prefix On;\n");
+        out.write("}\n");
+        out.close();
+
+        YangNode node = manager.getDataModel("demo.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListenerTest.java
new file mode 100644
index 0000000..3ce2fd0
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListenerTest.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangAugment;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangNodeIdentifier;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing augment listener functionality.
+ */
+public class AugmentListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid augment statement.
+     */
+    @Test
+    public void processValidAugmentStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidAugmentStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangAugment yangAugment = (YangAugment) yangNode.getChild();
+        ListIterator<YangNodeIdentifier> nodeIdentifierIterator = yangAugment.getTargetNode().listIterator();
+        YangNodeIdentifier yangNodeIdentifier = nodeIdentifierIterator.next();
+        assertThat(yangNodeIdentifier.getPrefix(), is("if"));
+        assertThat(yangNodeIdentifier.getName(), is("interfaces"));
+
+        ListIterator<YangLeaf> leafIterator = yangAugment.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("ds0ChannelNumber"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("ChannelNumber"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.DERIVED));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListenerTest.java
new file mode 100644
index 0000000..ee418c2
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListenerTest.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
+/**
+ * Test cases for testing base rule listener functionality.
+ */
+public class BaseFileListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Checks for exception if stack of parsable data is not empty at the entry
+     * of yang base rule.
+     */
+    @Test
+    public void processYangFileEntryNonEmptyStack() {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid holder for yangbase before processing.");
+
+        YangModule tmpModule = new YangModule();
+        TreeWalkListener listener = new TreeWalkListener();
+        listener.getParsedDataStack().push(tmpModule);
+        GeneratedYangParser.YangfileContext ctx = null;
+        BaseFileListener.processYangFileEntry(listener, ctx);
+    }
+
+    /**
+     * Checks that exception shouldn't be generated if stack of parsable data is
+     * empty at the entry of yang base rule.
+     */
+    @Test
+    public void processYangFileEntryEmptyStack() {
+
+        TreeWalkListener listener = new TreeWalkListener();
+        GeneratedYangParser.YangfileContext ctx = null;
+        BaseFileListener.processYangFileEntry(listener, ctx);
+    }
+
+    /**
+     * Checks that exception should be generated if stack of parsable data is
+     * not empty at the exit of yang base rule.
+     */
+    @Test
+    public void processYangFileExitEmptyStack() {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Missing holder at yangbase after processing.");
+
+        TreeWalkListener listener = new TreeWalkListener();
+        GeneratedYangParser.YangfileContext ctx = null;
+        BaseFileListener.processYangFileExit(listener, ctx);
+    }
+
+    /**
+     * Checks that exception shouldn't be generated if stack of parsable data is
+     * empty at the exit of yang base rule.
+     */
+    @Test
+    public void processYangFileExitNonEmptyStack() {
+
+        TreeWalkListener listener = new TreeWalkListener();
+        GeneratedYangParser.YangfileContext ctx = null;
+        BaseFileListener.processYangFileEntry(listener, ctx);
+    }
+
+    /**
+     * Checks that after popping out the parsable node from stack it should be
+     * empty.
+     */
+    @Test
+    public void processYangFileExitStackErrorExtraEntryTest() {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid holder for yangbase after processing.");
+
+        YangModule tmpModule = new YangModule();
+        YangModule tmpModule2 = new YangModule();
+        TreeWalkListener listener = new TreeWalkListener();
+        listener.getParsedDataStack().push(tmpModule);
+        listener.getParsedDataStack().push(tmpModule2);
+        GeneratedYangParser.YangfileContext ctx = null;
+        BaseFileListener.processYangFileExit(listener, ctx);
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BelongstoListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BelongstoListenerTest.java
new file mode 100644
index 0000000..927a2d6
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BelongstoListenerTest.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.CustomExceptionMatcher;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing belongsto listener functionality.
+ */
+public class BelongstoListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if mandatory belongsto parameter "prefix" is not present.
+     */
+    @Test
+    public void processBelongsToWithoutPrefix() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting 'prefix'");
+        thrown.expect(CustomExceptionMatcher.errorLocation(4, 0));
+        YangNode node = manager.getDataModel("src/test/resources/BelongsToWithoutPrefix.yang");
+    }
+
+    /**
+     * Checks that prefix must be present only once in belongsto.
+     */
+    @Test
+    public void processBelongsToDualPrefix() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'prefix' expecting '}'");
+        thrown.expect(CustomExceptionMatcher.errorLocation(5, 0));
+        YangNode node = manager.getDataModel("src/test/resources/BelongsToDualPrefix.yang");
+    }
+
+    /**
+     * Checks if belongsto listener updates the date model tree.
+     */
+    @Test
+    public void processBelongsToWithPrefix() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/BelongsToWithPrefix.yang");
+        YangSubModule yangNode = (YangSubModule) node;
+        assertThat(yangNode.getBelongsTo().getBelongsToModuleName(), is("ONOS"));
+    }
+
+    /**
+     * Checks if mandatory parameter "belongsto" is present.
+     */
+    @Test
+    public void processSubModuleWithoutBelongsTo() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting 'belongs-to'");
+        thrown.expect(CustomExceptionMatcher.errorLocation(3, 0));
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleWithoutBelongsTo.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BitListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BitListenerTest.java
new file mode 100644
index 0000000..6487172
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/BitListenerTest.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangBit;
+import org.onosproject.yangutils.datamodel.YangBits;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangUnion;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Set;
+
+/**
+ * Test cases for bit listener.
+ */
+public class BitListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks bit statement without position.
+     */
+    @Test
+    public void processBitTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/BitTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("mybits"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("bits"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.BITS));
+        assertThat(((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitsName(),
+                is("mybits"));
+
+        Set<YangBit> bitSet = ((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            } else if (tmp.getBitName().equals("Ten-Mb-only")) {
+                assertThat(tmp.getPosition(), is(2));
+            }
+        }
+    }
+
+    /**
+     * Checks bit statement with typedef.
+     */
+    @Test
+    public void processBitTypedefStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/BitTypedefStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
+        assertThat(typedef.getName(), is("type15"));
+
+        YangType type = typedef.getTypeList().iterator().next();
+        assertThat(type.getDataType(), is(YangDataTypes.BITS));
+        assertThat(type.getDataTypeName(), is("bits"));
+        Set<YangBit> bitSet = ((YangBits) type.getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            }
+        }
+    }
+
+    /**
+     * Checks bit statement with union.
+     */
+    @Test
+    public void processBitUnionStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/BitUnionStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("type15"));
+
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UNION));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("union"));
+
+        YangUnion yangUnion = (YangUnion) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        List<YangType<?>> typeList = yangUnion.getTypeList();
+        ListIterator<YangType<?>> typeListIterator = typeList.listIterator();
+        YangType<?> yangType = typeListIterator.next();
+
+        assertThat(yangType.getDataType(), is(YangDataTypes.BITS));
+        assertThat(yangType.getDataTypeName(), is("bits"));
+        Set<YangBit> bitSet = ((YangBits) yangType.getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            }
+        }
+    }
+
+    /**
+     * Checks if enum with same name is not allowed.
+     */
+    @Test(expected = ParserException.class)
+    public void processBitWithDuplicateName() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/BitWithDuplicateName.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/CaseListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/CaseListenerTest.java
new file mode 100644
index 0000000..675a9e9
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/CaseListenerTest.java
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangCase;
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+/**
+ * Test cases for case listener.
+ */
+public class CaseListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks multiple case statement.
+     */
+    @Test
+    public void processCaseStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/CaseStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+
+        YangCase yangCase1 = (YangCase) yangChoice.getChild();
+        assertThat(yangCase1.getName(), is("sports-arena"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator1 = yangCase1.getListOfLeaf().listIterator();
+        YangLeaf leafInfo1 = leafIterator1.next();
+
+        assertThat(leafInfo1.getName(), is("pretzel"));
+
+        YangCase yangCase2 = (YangCase) yangCase1.getNextSibling();
+        assertThat(yangCase2.getName(), is("late-night"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator2 = yangCase2.getListOfLeaf().listIterator();
+        YangLeaf leafInfo2 = leafIterator2.next();
+
+        assertThat(leafInfo2.getName(), is("chocolate"));
+    }
+
+    /**
+     * Checks duplicate case in choice.
+     */
+    @Test(expected = ParserException.class)
+    public void processDuplicateCaseInChoice() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateCaseInChoice.yang");
+    }
+
+    /**
+     * Checks duplicate leaf at different hierarchy.
+     */
+    @Test(expected = ParserException.class)
+    public void processDuplicateLeafInHierarchy() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateLeafInHierarchy.yang");
+    }
+
+    /**
+     * Checks duplicate leaf in different case within choice.
+     */
+    @Test(expected = ParserException.class)
+    public void processDuplicateLeafInChoice() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateLeafInChoice.yang");
+    }
+
+    /**
+     * Checks same case within different choice.
+     */
+    @Test
+    public void processCaseStatementSameEntryDifferentChoice() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/CaseStatementSameEntryDifferentChoice.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+
+        YangCase yangCase1 = (YangCase) yangChoice.getChild();
+        assertThat(yangCase1.getName(), is("sports-arena"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator1 = yangCase1.getListOfLeaf().listIterator();
+        YangLeaf leafInfo1 = leafIterator1.next();
+
+        assertThat(leafInfo1.getName(), is("pretzel"));
+
+        YangChoice yangChoice2 = (YangChoice) yangChoice.getNextSibling();
+        assertThat(yangChoice2.getName(), is("lunch"));
+
+        YangCase yangCase2 = (YangCase) yangChoice2.getChild();
+        assertThat(yangCase2.getName(), is("sports-arena"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator2 = yangCase2.getListOfLeaf().listIterator();
+        YangLeaf leafInfo2 = leafIterator2.next();
+
+        assertThat(leafInfo2.getName(), is("chocolate"));
+    }
+
+    /**
+     * Checks case choice hierarchy.
+     */
+    @Test
+    public void processCaseChoiceHierarchy() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/CaseChoiceHierarchy.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice1 = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice1.getName(), is("snack"));
+
+        YangCase yangCase1 = (YangCase) yangChoice1.getChild();
+        assertThat(yangCase1.getName(), is("sports-arena"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator1 = yangCase1.getListOfLeaf().listIterator();
+        YangLeaf leafInfo1 = leafIterator1.next();
+
+        assertThat(leafInfo1.getName(), is("pretzel"));
+
+        YangCase yangCase2 = (YangCase) yangCase1.getNextSibling();
+        assertThat(yangCase2.getName(), is("late-night"));
+
+        YangChoice yangChoice2 = (YangChoice) yangCase2.getChild();
+        assertThat(yangChoice2.getName(), is("dinner"));
+
+        YangCase yangCase3 = (YangCase) yangChoice2.getChild();
+        assertThat(yangCase3.getName(), is("late-night"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator2 = yangCase3.getListOfLeaf().listIterator();
+        YangLeaf leafInfo2 = leafIterator2.next();
+        assertThat(leafInfo2.getName(), is("beer"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListenerTest.java
new file mode 100644
index 0000000..9dcf448
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListenerTest.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+/**
+ * Test cases for choice listener.
+ */
+public class ChoiceListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks choice statement without body.
+     */
+    @Test
+    public void processChoiceStatementWithoutBody() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceStatementWithoutBody.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+    }
+
+    /**
+     * Checks choice statement with stmt end.
+     */
+    @Test
+    public void processChoiceStatementWithStmtend() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceStatementWithStmtend.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+    }
+
+    /**
+     * Checks choice statement duplicate entry.
+     */
+    @Test(expected = ParserException.class)
+    public void processChoiceStatementDuplicateEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceStatementDuplicateEntry.yang");
+    }
+
+    /**
+     * Checks choice statement with same entry in two different container.
+     */
+    @Test
+    public void processChoiceStatementSameEntryDifferentContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceStatementSameEntryDifferentContainer.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer1 = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer1.getName(), is("food1"));
+
+        YangChoice yangChoice1 = (YangChoice) yangContainer1.getChild();
+        assertThat(yangChoice1.getName(), is("snack"));
+
+        YangContainer yangContainer2 = (YangContainer) yangNode.getChild().getNextSibling();
+        assertThat(yangContainer2.getName(), is("food2"));
+
+        YangChoice yangChoice2 = (YangChoice) yangContainer2.getChild();
+        assertThat(yangChoice2.getName(), is("snack"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListenerTest.java
new file mode 100644
index 0000000..d129e38
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListenerTest.java
@@ -0,0 +1,534 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for config listener.
+ */
+public class ConfigListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid config statement.
+     */
+    @Test
+    public void processConfigTrue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ConfigTrue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the Config value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks valid config statement.
+     */
+    @Test
+    public void processConfigFalse() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalse.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the Config value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(false));
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : config value invalid is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigInvalidValue.yang");
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigEmptyValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input ';'");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigEmptyValue.yang");
+    }
+
+    /**
+     * Checks config statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementConfig() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'config' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+                + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementConfig.yang");
+    }
+
+    /**
+     * Checks config statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementConfig.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks config statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementConfig.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and config value is set.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid config statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementConfig.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether config value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks config statement's default Value.
+     */
+    @Test
+    public void processConfigDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ConfigDefaultValue.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks whether exception is throw when node's parent config set to false,
+     * no node underneath it can have config set to true.
+     */
+    @Test
+    public void processConfigFalseParentContainerChildLeafList() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Unhandled parsed data at container \"valid\" after "
+                + "processing.\nError Information: If a container has \"config\" set to \"false\", no node underneath "
+                + "it can have \"config\" set to \"true\".");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseParentContainerChildLeafList.yang");
+    }
+
+    /**
+     * Checks whether exception is throw when node's parent config set to false,
+     * no node underneath it can have config set to true.
+     */
+    @Test
+    public void processConfigFalseParentContainerChildLeaf() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Unhandled parsed data at container \"valid\" after "
+                + "processing.\nError Information: If a container has \"config\" set to \"false\", no node underneath "
+                + "it can have \"config\" set to \"true\".");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseParentContainerChildLeaf.yang");
+    }
+
+    /**
+     * Checks whether exception is throw when node's parent config set to false,
+     * no node underneath it can have config set to true.
+     */
+    @Test
+    public void processConfigFalseParentListChildLeafList() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Unhandled parsed data at list \"valid\" after"
+                + " processing.\nError Information: If a list has \"config\" set to \"false\", no node underneath"
+                + " it can have \"config\" set to \"true\".");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseParentListChildLeafList.yang");
+    }
+
+    /**
+     * Checks whether exception is throw when node's parent config set to false,
+     * no node underneath it can have config set to true.
+     */
+    @Test
+    public void processConfigFalseParentListChildLeaf() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Unhandled parsed data at list \"valid\" after"
+                + " processing.\nError Information: If a list has \"config\" set to \"false\", no node underneath"
+                + " it can have \"config\" set to \"true\".");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseParentListChildLeaf.yang");
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigContainerSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigContainerSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("hello"));
+        assertThat(container.isConfig(), is(true));
+
+        YangNode containerNode = container.getChild();
+        assertThat(containerNode instanceof YangContainer, is(true));
+        YangContainer childContainer = (YangContainer) containerNode;
+        assertThat(childContainer.getName(), is("valid"));
+        assertThat(childContainer.isConfig(), is(true));
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigContainerSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigContainerSubStatementLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+
+        ListIterator<YangLeafList> leafListIterator = container.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether config value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigContainerSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigContainerSubStatementLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigContainerSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigContainerSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("hello"));
+        assertThat(container.isConfig(), is(true));
+
+        YangNode listNode = container.getChild();
+        assertThat(listNode instanceof YangList, is(true));
+        YangList childList = (YangList) listNode;
+        assertThat(childList.getName(), is("valid"));
+        assertThat(childList.isConfig(), is(true));
+
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigListSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigListSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangList list1 = (YangList) yangNode.getChild();
+        assertThat(list1.getName(), is("list1"));
+        assertThat(list1.isConfig(), is(true));
+
+        YangNode containerNode = list1.getChild();
+        assertThat(containerNode instanceof YangContainer, is(true));
+        YangContainer childContainer = (YangContainer) containerNode;
+        assertThat(childContainer.getName(), is("container1"));
+        assertThat(childContainer.isConfig(), is(true));
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigListSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigListSubStatementLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangList list1 = (YangList) yangNode.getChild();
+        assertThat(list1.getName(), is("valid"));
+        assertThat(list1.isConfig(), is(true));
+
+        ListIterator<YangLeafList> leafListIterator = list1.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether config value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigListSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigListSubStatementLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangList list1 = (YangList) yangNode.getChild();
+        assertThat(list1.getName(), is("valid"));
+        assertThat(list1.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = list1.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks when config is not specified, the default is same as the parent's schema node's
+     * config statement's value.
+     */
+    @Test
+    public void processNoConfigListSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NoConfigListSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangList list1 = (YangList) yangNode.getChild();
+        assertThat(list1.getName(), is("valid"));
+        assertThat(list1.isConfig(), is(true));
+
+        YangNode listNode = list1.getChild();
+        assertThat(listNode instanceof YangList, is(true));
+        YangList childList = (YangList) listNode;
+        assertThat(childList.getName(), is("list1"));
+        assertThat(childList.isConfig(), is(true));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContactListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContactListenerTest.java
new file mode 100644
index 0000000..7c8c5e9
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContactListenerTest.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing contact listener functionality.
+ */
+public class ContactListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if contact listener updates the data model tree.
+     */
+    @Test
+    public void processContactValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContactValidEntry.yang");
+
+        // Checks for the contact value in data model tree.
+        assertThat(((YangModule) node).getContact(), is("\"WG List:  <mailto:spring@ietf.org>\nEditor:    "
+                + "Stephane Litkowski\n           " + "<mailto:stephane.litkowski@orange.com>\""));
+    }
+
+    /**
+     * Checks that contact must be present only once.
+     */
+    @Test(expected = ParserException.class)
+    public void processContactDualEntryTest() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContactDualEntryTest.yang");
+
+    }
+
+    /**
+     * Checks that contact can have a string value without double quotes.
+     */
+    @Test
+    public void processContactWithoutQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContactWithoutQuotes.yang");
+
+        // Checks for the contact value in data model tree.
+        assertThat(((YangModule) node).getContact(), is("WG"));
+    }
+
+    /**
+     * Checks if contact is not empty.
+     */
+    @Test(expected = ParserException.class)
+    public void processContactWithEmptyString() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContactWithEmptyString.yang");
+    }
+
+    /**
+     * Checks that contact must be present after namespace.
+     */
+    @Test(expected = ParserException.class)
+    public void processContactIncorrectOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContactIncorrectOrder.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListenerTest.java
new file mode 100644
index 0000000..a149da2
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListenerTest.java
@@ -0,0 +1,232 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing container listener.
+ */
+public class ContainerListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks container statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+    }
+
+    /**
+     * Checks if container identifier in module is duplicate.
+     */
+    @Test(expected = ParserException.class)
+    public void processModuleDuplicateContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleDuplicateContainer.yang");
+    }
+
+    /**
+     * Checks if container identifier in container is duplicate.
+     */
+    @Test(expected = ParserException.class)
+    public void processContainerDuplicateContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerDuplicateContainer.yang");
+    }
+
+    /**
+     * Checks if container identifier in list is duplicate.
+     */
+    @Test(expected = ParserException.class)
+    public void processListDuplicateContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListDuplicateContainer.yang");
+    }
+
+    /**
+     * Checks if container identifier collides with list at same level.
+     */
+    @Test(expected = ParserException.class)
+    public void processDuplicateContainerAndList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateContainerAndList.yang");
+    }
+
+    /**
+     * Checks container statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        // Check whether the container is child of container
+        YangContainer yangContainer1 = (YangContainer) yangContainer.getChild();
+        assertThat(yangContainer1.getName(), is("valid"));
+    }
+
+    /**
+     * Checks container statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList1 = (YangList) yangNode.getChild();
+        assertThat(yangList1.getName(), is("ospf"));
+
+        ListIterator<String> keyList = yangList1.getKeyList().listIterator();
+        assertThat(keyList.next(), is("process-id"));
+
+        // Check whether the list is child of list
+        YangContainer yangContainer = (YangContainer) yangList1.getChild();
+        assertThat(yangContainer.getName(), is("interface"));
+    }
+
+    /**
+     * Checks container with all its sub-statements.
+     */
+    @Test
+    public void processContainerSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+
+        // Check whether container properties as set correctly.
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        assertThat(yangContainer.isConfig(), is(true));
+        assertThat(yangContainer.getPresence(), is("\"ospf logs\""));
+        assertThat(yangContainer.getDescription(), is("\"container description\""));
+        assertThat(yangContainer.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangContainer.getReference(), is("\"container reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangContainer.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks cardinality of sub-statements of container.
+     */
+    @Test
+    public void processContainerSubStatementCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"reference\" is defined more than once in \"container valid\".");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementCardinality.yang");
+    }
+
+    /**
+     * Checks container as root node.
+     */
+    @Test
+    public void processContainerRootNode() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input 'container'");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerRootNode.yang");
+    }
+
+    /**
+     * Checks invalid identifier for container statement.
+     */
+    @Test
+    public void processContainerInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : container name 1valid is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerInvalidIdentifier.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListenerTest.java
new file mode 100644
index 0000000..2aab556
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListenerTest.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing default listener functionality.
+ */
+public class DefaultListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if default value is set correctly.
+     */
+    @Test
+    public void processLeafSubStatementDefault() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafSubStatementDefault.yang");
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDefaultValueInString(), is("\"1\""));
+    }
+
+    /**
+     * Checks if default value is set correctly.
+     */
+    @Test
+    public void processChoiceSubStatementDefault() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceSubStatementDefault.yang");
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+        assertThat(yangChoice.getDefaultValueInString(), is("\"hello\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListenerTest.java
new file mode 100644
index 0000000..c3989a6
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListenerTest.java
@@ -0,0 +1,251 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for description listener.
+ */
+public class DescriptionListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid description statement.
+     */
+    @Test
+    public void processDescriptionValidStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionValidStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the description is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid description statement.
+     */
+    @Test
+    public void processDescriptionWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of module.
+     */
+    @Test
+    public void processDescriptionEmptyStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionEmptyStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of revision.
+     */
+    @Test
+    public void processRevisionSubStatementRevision() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionSubStatementRevision.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"module description\""));
+        assertThat(yangNode.getRevision().getDescription(), is("\"revision description\""));
+    }
+
+    /**
+     * Checks description statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.getDescription(), is("\"container description\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks description statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementDescription.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and description value is set correctly.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getDescription(), is("\"list description\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether description value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/EnumListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/EnumListenerTest.java
new file mode 100644
index 0000000..a0bff1b
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/EnumListenerTest.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangEnum;
+import org.onosproject.yangutils.datamodel.YangEnumeration;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.ListIterator;
+import java.util.SortedSet;
+
+/**
+ * Test cases for enum listener.
+ */
+public class EnumListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks enum statement without value.
+     */
+    @Test
+    public void processEnumTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/EnumTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        SortedSet<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(0));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(1));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(2));
+            }
+        }
+    }
+
+    /**
+     * Checks if enum with same name is not allowed.
+     */
+    @Test(expected = ParserException.class)
+    public void processEnumWithDuplicateName() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/EnumWithDuplicateName.yang");
+    }
+
+    /**
+     * Checks enum boundary value.
+     */
+    @Test
+    public void processEnumBoundaryValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : value value 21474836472147483647 is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/EnumBoundaryValue.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown if value is not specified following max enum value.
+     */
+    @Test
+    public void processEnumMaxNextValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : "
+                + "An enum value MUST be specified for enum substatements following the one"
+                + "with the current highest value");
+        YangNode node = manager.getDataModel("src/test/resources/EnumMaxNextValue.yang");
+    }
+
+    /**
+     * Checks enum values stored are sorted.
+     */
+    @Test
+    public void processEnumSorted() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/EnumSorted.yang");
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("ifType"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("ifType_enum"));
+
+        SortedSet<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        Iterator<YangEnum> enumIterator = enumSet.iterator();
+        assertThat(enumIterator.next().getNamedValue(), is("five"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListenerTest.java
new file mode 100644
index 0000000..acd0c8a
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListenerTest.java
@@ -0,0 +1,189 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing grouping listener.
+ */
+public class GroupingListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks grouping statement inside module.
+     */
+    @Test
+    public void processGroupingInModule() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/GroupingInModule.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangNode.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        ListIterator<YangLeaf> leafIterator = yangGrouping.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("address"));
+    }
+
+    /**
+     * Checks grouping statement inside container.
+     */
+    @Test
+    public void processGroupingInContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/GroupingInContainer.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangContainer.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        ListIterator<YangLeaf> leafIterator = yangGrouping.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("address"));
+    }
+
+    /**
+     * Checks grouping statement inside list.
+     */
+    @Test
+    public void processGroupingInList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/GroupingInList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangList.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        ListIterator<YangLeaf> leafIterator = yangGrouping.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("address"));
+    }
+
+    /**
+     * Checks grouping with attributes.
+     */
+    @Test
+    public void processGroupingAttributes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/GroupingAttributes.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangList.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+        assertThat(yangGrouping.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangGrouping.getReference(), is("\"RFC 6020\""));
+        assertThat(yangGrouping.getDescription(), is("\"grouping under test\""));
+
+        ListIterator<YangLeaf> leafIterator = yangGrouping.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("address"));
+    }
+
+    /**
+     * Checks duplicate grouping in list.
+     */
+    @Test(expected = ParserException.class)
+    public void processDuplicateGroupingInList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateGroupingInList.yang");
+    }
+
+    /**
+     * Checks duplicate grouping in container.
+     */
+    @Test (expected = ParserException.class)
+    public void processDuplicateGroupingInContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateGroupingInContainer.yang");
+    }
+
+    /**
+     * Checks duplicate grouping in module.
+     */
+    @Test (expected = ParserException.class)
+    public void processDuplicateGroupingInModule() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DuplicateGroupingInModule.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ImportListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ImportListenerTest.java
new file mode 100644
index 0000000..9797e5e
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ImportListenerTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing import listener functionality.
+ */
+public class ImportListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if mandatory parameter prefix is present in import.
+     */
+    @Test(expected = ParserException.class)
+    public void processImportWithoutPrefix() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportWithoutPrefix.yang");
+    }
+
+    /**
+     * Checks that prefix must be present only once in import.
+     */
+    @Test(expected = ParserException.class)
+    public void processImportWithDualPrefix() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportWithDualPrefix.yang");
+    }
+
+    /**
+     * Checks for the correct order of prefix in import.
+     */
+    @Test(expected = ParserException.class)
+    public void processImportInvalidOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportInvalidOrder.yang");
+    }
+
+    /**
+     * Checks if import listener updates the data model tree.
+     */
+    @Test
+    public void processImportValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportValidEntry.yang");
+
+        // Checks for the revision value in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getRevision(), is("2015-02-03"));
+        // Checks for the prefix id in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getPrefixId(), is("On2"));
+        // Checks for the module name in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getModuleName(), is("ietf"));
+    }
+
+    /**
+     * Checks if optional parameter revision is not mandatory in import.
+     */
+    @Test
+    public void processImportWithoutRevision() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportWithoutRevision.yang");
+
+        // Checks for the prefix id in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getPrefixId(), is("On2"));
+        // Checks for the module name in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getModuleName(), is("ietf"));
+    }
+
+    /**
+     * Checks if multiple imports are allowed.
+     */
+    @Test()
+    public void processImportMultipleInstance() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ImportMultipleInstance.yang");
+
+        // Checks for the prefix id in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getPrefixId(), is("On2"));
+        // Checks for the module name in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getModuleName(), is("ietf"));
+
+        // Checks for the prefix id in data model tree.
+        assertThat(((YangModule) node).getImportList().get(1).getPrefixId(), is("On3"));
+        // Checks for the module name in data model tree.
+        assertThat(((YangModule) node).getImportList().get(1).getModuleName(), is("itut"));
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListenerTest.java
new file mode 100644
index 0000000..452fc89
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListenerTest.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing include listener functionality.
+ */
+public class IncludeListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if include listener with ; is valid and updates the data
+     * model tree.
+     */
+    @Test
+    public void processIncludeWithStmtend() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeWithStmtend.yang");
+
+        // Checks for the sub module name in data model tree.
+        assertThat(((YangModule) node).getIncludeList().get(0).getSubModuleName(), is("itut"));
+    }
+
+    /**
+     * Checks if include listener with braces and without revision date is valid
+     * and updates the data model tree.
+     */
+    @Test
+    public void processIncludeWithEmptyBody() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeWithEmptyBody.yang");
+
+        // Checks for the sub module name in data model tree.
+        assertThat(((YangModule) node).getIncludeList().get(0).getSubModuleName(), is("itut"));
+    }
+
+    /**
+     * Checks if include listener with braces and with revision date is valid
+     * and updates the data model tree.
+     */
+    @Test
+    public void processIncludeWithDate() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeWithDate.yang");
+
+        // Checks for the sub module name in data model tree.
+        assertThat(((YangModule) node).getIncludeList().get(0).getSubModuleName(), is("itut"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+    }
+
+    /**
+     * Checks if include has more than one occurrence.
+     */
+    @Test
+    public void processIncludeMultiInstance() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeMultiInstance.yang");
+
+        // Checks for the sub module name in data model tree.
+        assertThat(((YangModule) node).getIncludeList().get(0).getSubModuleName(), is("itut"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getSubModuleName(), is("sdn"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getRevision(), is("2014-02-03"));
+    }
+
+    /**
+     * Checks if include and import can come in any order.
+     */
+    @Test
+    public void processIncludeImportAnyOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeImportAnyOrder.yang");
+
+        // Checks for the sub module name in data model tree.
+        assertThat(((YangModule) node).getIncludeList().get(0).getSubModuleName(), is("itut"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getSubModuleName(), is("sdn"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getRevision(), is("2014-02-03"));
+    }
+
+    /**
+     * Checks if syntax of Include is not correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processIncludeInvalidSyntax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeInvalidSyntax.yang");
+    }
+
+    /**
+     * Checks if syntax of revision date in Include is not correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processIncludeInvalidDateSyntax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IncludeInvalidDateSyntax.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/InputListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/InputListenerTest.java
new file mode 100644
index 0000000..c85c1d5
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/InputListenerTest.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangRpc;
+import org.onosproject.yangutils.datamodel.YangInput;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing Input listener functionality.
+ */
+public class InputListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks input statements with data definition statements as sub-statements.
+     */
+    @Test
+    public void processInputStatementWithDataDefinition() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/InputStatementWithDataDefinition.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangRpc yangRpc = (YangRpc) yangNode.getChild();
+        assertThat(yangRpc.getName(), is("activate-software-image"));
+
+        YangInput yangInput = (YangInput) yangRpc.getChild();
+        assertThat(yangInput.getName(), is("activate-software-image_input"));
+        ListIterator<YangLeaf> leafIterator = yangInput.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("image-name"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+
+        YangList yangList = (YangList) yangInput.getChild();
+        assertThat(yangList.getName(), is("ospf"));
+        assertThat(yangList.getKeyList().contains("invalid-interval"), is(true));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getMaxElements(), is(10));
+        assertThat(yangList.getMinElements(), is(3));
+        leafIterator = yangList.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+
+        YangContainer yangContainer = (YangContainer) yangList.getNextSibling();
+        assertThat(yangContainer.getName(), is("isis"));
+
+        leafIterator = yangContainer.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+    }
+
+    /**
+     * Checks input statements with type-def statement as sub-statements.
+     */
+    @Test
+    public void processInputStatementWithTypedef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/InputStatementWithTypedef.yang");
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangRpc yangRpc = (YangRpc) yangNode.getChild();
+        assertThat(yangRpc.getName(), is("activate-software-image"));
+
+        YangInput yangInput = (YangInput) yangRpc.getChild();
+        assertThat(yangInput.getName(), is("activate-software-image_input"));
+        YangTypeDef typeDef = (YangTypeDef) yangInput.getChild();
+        assertThat(typeDef.getName(), is("my-type"));
+        assertThat(typeDef.getStatus(), is(YangStatusType.DEPRECATED));
+        assertThat(typeDef.getTypeDefBaseType().getDataType(), is(YangDataTypes.INT32));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/KeyListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/KeyListenerTest.java
new file mode 100644
index 0000000..510b313
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/KeyListenerTest.java
@@ -0,0 +1,264 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for key listener.
+ */
+public class KeyListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks key statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementKey() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementKey.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Check multiple key values.
+     */
+    @Test
+    public void processMultipleKeyValues() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultipleKeyValues.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        List<String> keyList = yangList.getKeyList();
+        assertThat(keyList.contains("ospf"), is(true));
+        assertThat(keyList.contains("isis"), is(true));
+    }
+
+    /**
+     * Checks key statement without statement end.
+     */
+    @Test
+    public void processKeyWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaf' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/KeyWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processConfigFalseNoKey() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseNoKey.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+    }
+
+    /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processConfigFalseValidKeyValidLeaf() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseValidKeyValidLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processConfigFalseValidKeyValidLeafList() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalseValidKeyValidLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Checks whether exception is thrown when list's config is set to true and there is no key.
+     */
+    @Test
+    public void processConfigTrueNoKey() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("A list must have atleast one key leaf if config is true");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigTrueNoKey.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when list's config is set to true and there is no leaf.
+     */
+    @Test
+    public void processConfigTrueNoleafNoLeafList() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("A list must have atleast one key leaf if config is true");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigTrueNoleafNoLeafList.yang");
+    }
+
+    /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processConfigTrueValidKeyValidLeaf() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/ConfigTrueValidKeyValidLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Checks key values are set correctly.
+     */
+    @Test
+    public void processKeyWithUsesInList() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/KeyWithUsesInList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild().getNextSibling();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Checks whether exception is thrown when key leaf identifier is not found in list.
+     */
+    @Test
+    public void processInvalidLeafIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("An identifier, in key, must refer to a child leaf of the list");
+        YangNode node = manager.getDataModel("src/test/resources/InvalidLeafIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when key leaf-list identifier is not found in list.
+     */
+    @Test
+    public void processInvalidLeafListIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("An identifier, in key, must refer to a child leaf of the list");
+        YangNode node = manager.getDataModel("src/test/resources/InvalidLeafListIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when key leaf-list is of type empty.
+     */
+    @Test
+    public void processKeyLeafListTypeEmpty() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("A leaf-list that is part of the key must not be the built-in type \"empty\".");
+        YangNode node = manager.getDataModel("src/test/resources/KeyLeafListTypeEmpty.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when key leaf is of type empty.
+     */
+    @Test
+    public void processKeyLeafTypeEmpty() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("A leaf that is part of the key must not be the built-in type \"empty\".");
+        YangNode node = manager.getDataModel("src/test/resources/KeyLeafTypeEmpty.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListenerTest.java
new file mode 100644
index 0000000..8e7489b
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListenerTest.java
@@ -0,0 +1,211 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing leaf-list listener.
+ */
+public class LeafListListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks all the values of leaf-list sub-statements are set correctly.
+     */
+    @Test
+    public void processLeafListSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getMaxElelements(), is(3));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list identifier starts with
+     * digit.
+     */
+    @Test
+    public void processLeafListInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : leaf-list name 1invalid-interval is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list keyword is incorrect.
+     */
+    @Test
+    public void processLeafListInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaflist' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+                + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list keyword without Left
+     * brace as per grammar.
+     */
+    @Test
+    public void processLeafListWithoutLeftBrace() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing '{' at 'type'");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListWithoutLeftBrace.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when config statement cardinality is
+     * not as per grammar.
+     */
+    @Test
+    public void processLeafListConfigInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"config\" is defined more than once in \"leaf-list " +
+                "invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListConfigInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when units statement cardinality is
+     * not as per grammar.
+     */
+    @Test
+    public void processLeafListUnitsInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"units\" is defined more than once in \"leaf-list invalid-interval\"");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListUnitsInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks leaf-list statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementLeafList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        //Check whether the container is child of module.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+
+        // Check whether leaf-list properties as set correctly.
+        ListIterator<YangLeafList> leafListIterator = container.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getMinElements(), is(1));
+        assertThat(leafListInfo.getMaxElelements(), is(2147483647));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks leaf-list statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        // Check whether leaf-list properties as set correctly.
+        ListIterator<YangLeafList> leafListIterator = yangList.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListenerTest.java
new file mode 100644
index 0000000..b330e53
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LeafListenerTest.java
@@ -0,0 +1,237 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing leaf listener.
+ */
+public class LeafListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks all the values of leaf sub-statements are set correctly.
+     */
+    @Test
+    public void processLeafSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafSubStatements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf identifier starts with
+     * digit.
+     */
+    @Test
+    public void processLeafInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : leaf name 1invalid-interval is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf keyword is incorrect.
+     */
+    @Test
+    public void processLeafInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leafs' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+                + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/LeafInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf keyword without Left brace
+     * as per grammar.
+     */
+    @Test
+    public void processLeafWithoutLeftBrace() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing '{' at 'type'");
+        YangNode node = manager.getDataModel("src/test/resources/LeafWithoutLeftBrace.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when config statement cardinality is
+     * not as per grammar.
+     */
+    @Test
+    public void processLeafConfigInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"config\" is defined more than once in \"leaf invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/LeafConfigInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when mandatory statement cardinality
+     * is not as per grammar.
+     */
+    @Test
+    public void processLeafMandatoryInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"mandatory\" is defined more than once in \"leaf invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/LeafMandatoryInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks leaf statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementLeaf.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        //Check whether the container is child of module.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks duplicate leaf statement as sub-statement of module.
+     */
+    @Test(expected = ParserException.class)
+    public void processModuleWithDuplicateLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleWithDuplicateLeaf.yang");
+    }
+
+    /**
+     * Checks duplicate leaf statement as sub-statement of container.
+     */
+    @Test(expected = ParserException.class)
+    public void processContainerWithDuplicateLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerWithDuplicateLeaf.yang");
+    }
+
+    /**
+     * Checks duplicate leaf statement as sub-statement of list.
+     */
+    @Test(expected = ParserException.class)
+    public void processListWithDuplicateLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListWithDuplicateLeaf.yang");
+    }
+
+    /**
+     * Checks leaf statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java
new file mode 100644
index 0000000..0c862ba
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/LengthRestrictionListenerTest.java
@@ -0,0 +1,302 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangRangeInterval;
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.datamodel.utils.builtindatatype.YangUint64;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for length restriction listener.
+ */
+public class LengthRestrictionListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid length statement as sub-statement of leaf statement.
+     */
+    @Test
+    public void processValidLengthStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidLengthStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks valid length statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLengthStatementInsideLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthStatementInsideLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks valid length statement as sub-statement of typedef.
+     */
+    @Test
+    public void processLengthStatementInsideTypeDef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthStatementInsideTypeDef.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
+        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getTypeDefBaseType()
+                .getDataTypeExtendedInfo();
+
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks length statement with invalid type.
+     */
+    @Test
+    public void processLengthWithInvalidType() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : length name \"1..100\" can be used to restrict the built-in type" +
+                " string/binary or types derived from string/binary.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidType.yang");
+    }
+
+    /**
+     * Checks length statement with only start interval.
+     */
+    @Test
+    public void processLengthWithOneInterval() throws IOException, ParserException {
+
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithOneInterval.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(1)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(1)));
+    }
+
+    /**
+     * Checks length statement with min and max.
+     */
+    @Test
+    public void processLengthWithMinMax() throws IOException, ParserException {
+
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithMinMax.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(new BigInteger("18446744073709551615")));
+    }
+
+    /**
+     * Checks length statement with invalid integer pattern.
+     */
+    @Test
+    public void processLengthWithInvalidIntegerPattern() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : Input value \"a\" is not a valid uint64.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidIntegerPattern.yang");
+    }
+
+    /**
+     * Checks length statement with invalid interval.
+     */
+    @Test
+    public void processLengthWithInvalidInterval() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : 18446744073709551617 is greater than maximum value" +
+                " 18446744073709551615.");
+        YangNode node = manager.getDataModel("src/test/resources/LengthWithInvalidInterval.yang");
+    }
+
+    /**
+     * Checks valid length substatements.
+     */
+    @Test
+    public void processLengthSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        assertThat(lengthRestriction.getDescription(), is("\"length description\""));
+        assertThat(lengthRestriction.getReference(), is("\"length reference\""));
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+
+    /**
+     * Checks whether space can be allowed when length statement is present.
+     */
+    @Test
+    public void processLengthStatementWithSpace() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LengthStatementWithSpace.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        YangRangeRestriction lengthRestriction = stringRestriction.getLengthRestriction();
+
+        ListIterator<YangRangeInterval> lengthListIterator = lengthRestriction.getAscendingRangeIntervals()
+                .listIterator();
+
+        YangRangeInterval rangeInterval = lengthListIterator.next();
+
+        assertThat(((YangUint64) rangeInterval.getStartValue()).getValue(), is(BigInteger.valueOf(0)));
+        assertThat(((YangUint64) rangeInterval.getEndValue()).getValue(), is(BigInteger.valueOf(100)));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ListListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ListListenerTest.java
new file mode 100644
index 0000000..526a645
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ListListenerTest.java
@@ -0,0 +1,211 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing list listener.
+ */
+public class ListListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks list statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Checks list statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        // Check whether the list is child of container
+        YangList yangList = (YangList) yangContainer.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getKeyList().contains("invalid-interval"), is(true));
+    }
+
+    /**
+     * Checks list statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList1 = (YangList) yangNode.getChild();
+        assertThat(yangList1.getName(), is("ospf"));
+        assertThat(yangList1.getKeyList().contains("process-id"), is(true));
+
+        // Check whether the list is child of list
+        YangList yangList = (YangList) yangList1.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getKeyList().contains("invalid-interval"), is(true));
+    }
+
+    /**
+     * Checks list with all its sub-statements.
+     */
+    @Test
+    public void processListSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+
+        // Check whether list properties as set correctly.
+        assertThat(yangList.getName(), is("ospf"));
+        assertThat(yangList.getKeyList().contains("invalid-interval"), is(true));
+
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getMaxElements(), is(10));
+        assertThat(yangList.getMinElements(), is(3));
+        assertThat(yangList.getDescription(), is("\"list description\""));
+        assertThat(yangList.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangList.getReference(), is("\"list reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks cardinality of sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementsCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"reference\" is defined more than once in \"list valid\".");
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementsCardinality.yang");
+    }
+
+    /**
+     * Checks list statement without child.
+     */
+    @Test
+    public void processListStatementWithoutChild() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: Missing \"data-def-substatements\" in \"list valid\".");
+        YangNode node = manager.getDataModel("src/test/resources/ListStatementWithoutChild.yang");
+    }
+
+    /**
+     * Checks list as root node.
+     */
+    @Test
+    public void processListAsRootNode() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input 'list'");
+        YangNode node = manager.getDataModel("src/test/resources/ListAsRootNode.yang");
+    }
+
+    /**
+     * Checks invalid identifier for list statement.
+     */
+    @Test
+    public void processListInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : list name 1valid is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/ListInvalidIdentifier.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListenerTest.java
new file mode 100644
index 0000000..52e43a9
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListenerTest.java
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for mandatory listener.
+ */
+public class MandatoryListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid mandatory with value true statement.
+     */
+    @Test
+    public void processMandatoryTrue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryTrue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(true));
+    }
+
+    /**
+     * Checks valid mandatory with value false statement.
+     */
+    @Test
+    public void processMandatoryFalse() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryFalse.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(false));
+    }
+
+    /**
+     * Checks default value of mandatory statement.
+     */
+    @Test
+    public void processMandatoryDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(false));
+    }
+
+    /**
+     * Checks invalid of mandatory statement and expects exception.
+     */
+    @Test
+    public void processMandatoryEmptyStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input ';'");
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryEmptyStatement.yang");
+    }
+
+    /**
+     * Checks invalid mandatory statement(without statement end) and expects
+     * exception.
+     */
+    @Test
+    public void processMandatoryWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks mandatory statement as sub-statement of module and expects
+     * exception.
+     */
+    @Test
+    public void processModuleSubStatementMandatory() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'mandatory' expecting {'anyxml', 'augment', 'choice', 'contact',"
+                + " 'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference',"
+                + " 'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementMandatory.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListenerTest.java
new file mode 100644
index 0000000..aa0cee2
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListenerTest.java
@@ -0,0 +1,190 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing max-elements listener.
+ */
+public class MaxElementsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks max-elements as sub-statements of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementMaxElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementMaxElements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMaxElelements(), is(3));
+    }
+
+    /**
+     * Checks max-elements as sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementMaxElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementMaxElements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getMaxElements(), is(3));
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid max-elements keyword is
+     * given as input.
+     */
+    @Test
+    public void processMaxElementsInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input 'max-element' expecting {'config', 'description', 'if-feature',"
+                + " 'max-elements', 'min-elements', 'must', 'ordered-by', 'reference', 'status', 'type', 'units', "
+                + "'when', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when max-elements statement without
+     * statement end is given as input.
+     */
+    @Test
+    public void processMaxElementsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at 'description'");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when max-elements cardinality is not
+     * as per the grammar.
+     */
+    @Test
+    public void processMaxElementsCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"max-elements\" is defined more than once in \"leaf-list " +
+                "invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsCardinality.yang");
+    }
+
+    /**
+     * Checks unbounded value of max-elements statement.
+     */
+    @Test
+    public void processMaxElementsUnbounded() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsUnbounded.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMaxElelements(), is(2147483647));
+    }
+
+    /**
+     * Checks default value of max-elements statement.
+     */
+    @Test
+    public void processMaxElementsDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMaxElelements(), is(2147483647));
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements value is
+     * given as input.
+     */
+    @Test
+    public void processMaxElementsMaxValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : max-elements value 77777777777777777777777 is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsMaxValue.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java
new file mode 100644
index 0000000..c2f668b
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing min-elements listener.
+ */
+public class MinElementsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks min-elements as sub-statements of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementMinElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementMinElements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMinElements(), is(3));
+    }
+
+    /**
+     * Checks min-elements as sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementMinElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementMinElements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getMinElements(), is(3));
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements keyword is
+     * given as input.
+     */
+    @Test
+    public void processMinElementsInvalidKeyword() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input 'min-element' expecting {'config', 'description', 'if-feature',"
+                + " 'max-elements', 'min-elements', 'must', 'ordered-by', 'reference', 'status', 'type', 'units',"
+                + " 'when', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidKeyword.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements value is
+     * given as input.
+     */
+    @Test
+    public void processMinElementsInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : min-elements value asd is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidValue.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements value is
+     * given as input.
+     */
+    @Test
+    public void processMinElementsMaxValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : min-elements value 77777777777777777777777 is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsMaxValue.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when min-elements statement without
+     * statement end is given as input.
+     */
+    @Test
+    public void processMinElementsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at 'description'");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when min-elements cardinality is not
+     * as per the grammar.
+     */
+    @Test
+    public void processMinElementsInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"min-elements\" is defined more than once in \"leaf-list " +
+                "invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks min-element's default value.
+     */
+    @Test
+    public void processMinElementsDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMinElements(), is(0));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListenerTest.java
new file mode 100644
index 0000000..f77050a
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListenerTest.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing module listener functionality.
+ */
+public class ModuleListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Checks if module listener updates the data model root node.
+     */
+    @Test
+    public void processModuleValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleValidEntry.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+    }
+
+    /**
+     * Checks if module name is set correctly.
+     */
+    @Test(expected = ParserException.class)
+    public void processModuleInvalidEntryTest() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleWithInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when module length is greater than 64 characters.
+     */
+    @Test
+    public void processModuleInvalidIdentifierLength() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : module name Testttttttttttttttttttttttttttttttttttttttttttttttttttt" +
+                "tttttttttt is greater than 64 characters.");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleInvalidIdentifierLength.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListenerTest.java
new file mode 100644
index 0000000..0f35705
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListenerTest.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing namespace listener functionality.
+ */
+public class NamespaceListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks that value of namespace shouldn't have invalid spaces.
+     */
+    @Test(expected = ParserException.class)
+    public void processNamespaceWithInvalidSpaces() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NamespaceWithInvalidSpaces.yang");
+    }
+
+    /**
+     * Checks if namespace with double quotes is allowed.
+     */
+    @Test()
+    public void processNamespaceInDoubleQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NamespaceInDoubleQuotes.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getNameSpace().getUri(), is("\"urn:ietf:params:xml:ns:yang:ietf-ospf\""));
+    }
+
+    /**
+     * Checks if namespace without double quotes is allowed.
+     */
+    @Test()
+    public void processNamespaceWithoutQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NamespaceWithoutQuotes.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getNameSpace().getUri(), is("urn:ietf:params:xml:ns:yang:ietf-ospf"));
+    }
+
+    /**
+     * Checks if namespace is present only once.
+     */
+    @Test(expected = ParserException.class)
+    public void processNamespaceDualEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NamespaceDualEntry.yang");
+    }
+
+    /**
+     * Checks if mandatory parameter namespace is present.
+     */
+    @Test(expected = ParserException.class)
+    public void processNamespaceNoEntryTest() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/NamespaceNoEntryTest.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListenerTest.java
new file mode 100644
index 0000000..7da2468
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListenerTest.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangNotification;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing notification listener functionality.
+ */
+public class NotificationListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid notification statement.
+     */
+    @Test
+    public void processValidNotificationStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidNotificationStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangNotification yangNotification = (YangNotification) yangNode.getChild();
+        assertThat(yangNotification.getName(), is("link-failure"));
+        assertThat(yangNotification.getDescription(), is("\"A link failure has been detected\""));
+        assertThat(yangNotification.getStatus(), is(YangStatusType.DEPRECATED));
+        assertThat(yangNotification.getReference(), is("\"reference\""));
+
+        YangTypeDef typeDef = (YangTypeDef) yangNotification.getChild();
+        assertThat(typeDef.getName(), is("my-type"));
+        assertThat(typeDef.getStatus(), is(YangStatusType.DEPRECATED));
+
+        ListIterator<YangLeaf> leafIterator = yangNotification.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("if-name"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListenerTest.java
new file mode 100644
index 0000000..e9098d3
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListenerTest.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing organization listener functionality.
+ */
+public class OrganizationListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if organization listener updates the data model tree.
+     */
+    @Test
+    public void processOrganizationValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OrganizationValidEntry.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getOrganization(), is("\"IETF SPRING Working Group\""));
+    }
+
+    /**
+     * Checks that organization must be present only once.
+     */
+    @Test(expected = ParserException.class)
+    public void processOrganizationDualEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OrganizationDualEntry.yang");
+    }
+
+    /**
+     * Checks if organization entry syntax is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processOrganizationMissingValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OrganizationMissingValue.yang");
+    }
+
+    /**
+     * Checks if organization and namespace is present in correct order.
+     */
+    @Test(expected = ParserException.class)
+    public void processOrganizationInvalidOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OrganizationInvalidOrder.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OutputListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OutputListenerTest.java
new file mode 100644
index 0000000..a727092
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/OutputListenerTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangOutput;
+import org.onosproject.yangutils.datamodel.YangRpc;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing output listener functionality.
+ */
+public class OutputListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks output statements with data definition statements as sub-statements.
+     */
+    @Test
+    public void processOutputStatementWithDataDefinition() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OutputStatementWithDataDefinition.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangRpc yangRpc = (YangRpc) yangNode.getChild();
+        assertThat(yangRpc.getName(), is("activate-software-image"));
+
+        YangOutput yangOutput = (YangOutput) yangRpc.getChild();
+        assertThat(yangOutput.getName(), is("activate-software-image_output"));
+        ListIterator<YangLeaf> leafIterator = yangOutput.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("image-name"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+
+        YangList yangList = (YangList) yangOutput.getChild();
+        assertThat(yangList.getName(), is("ospf"));
+        assertThat(yangList.getKeyList().contains("invalid-interval"), is(true));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getMaxElements(), is(10));
+        assertThat(yangList.getMinElements(), is(3));
+        leafIterator = yangList.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+
+        YangContainer yangContainer = (YangContainer) yangList.getNextSibling();
+        assertThat(yangContainer.getName(), is("isis"));
+
+        leafIterator = yangContainer.getListOfLeaf().listIterator();
+        leafInfo = leafIterator.next();
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+    }
+
+    /**
+     * Checks output statements with type-def statement as sub-statements.
+     */
+    @Test
+    public void processOutputStatementWithTypedef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/OutputStatementWithTypedef.yang");
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangRpc yangRpc = (YangRpc) yangNode.getChild();
+        assertThat(yangRpc.getName(), is("activate-software-image"));
+
+        YangOutput yangOutput = (YangOutput) yangRpc.getChild();
+        assertThat(yangOutput.getName(), is("activate-software-image_output"));
+        YangTypeDef typeDef = (YangTypeDef) yangOutput.getChild();
+        assertThat(typeDef.getName(), is("my-type"));
+        assertThat(typeDef.getStatus(), is(YangStatusType.DEPRECATED));
+        assertThat(typeDef.getName(), is("my-type"));
+        assertThat(typeDef.getStatus(), is(YangStatusType.DEPRECATED));
+        assertThat(typeDef.getTypeDefBaseType().getDataType(), is(YangDataTypes.INT32));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
new file mode 100644
index 0000000..5216ef3
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangPatternRestriction;
+import org.onosproject.yangutils.datamodel.YangStringRestriction;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for pattern restriction listener.
+ */
+public class PatternRestrictionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid pattern statement as sub-statement of leaf statement.
+     */
+    @Test
+    public void processValidPatternStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidPatternStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processPatternStatementInsideLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementInsideLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement as sub-statement of typedef.
+     */
+    @Test
+    public void processPatternStatementInsideTypeDef() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementInsideTypeDef.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
+        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getTypeDefBaseType()
+                .getDataTypeExtendedInfo();
+
+        YangPatternRestriction yangPatternRestriction = stringRestriction.getPatternRestriction();
+        assertThat(yangPatternRestriction.getPatternList().listIterator().next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid multiple pattern statements.
+     */
+    @Test
+    public void processMultiplePatternStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultiplePatternStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks valid pattern statement with plus symbol in pattern.
+     */
+    @Test
+    public void processPatternStatementWithPlus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternStatementWithPlus.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("-[0-9]+|[0-9]+"));
+    }
+
+    /**
+     * Checks valid pattern substatement.
+     */
+    @Test
+    public void processPatternSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PatternSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("string"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.STRING));
+        YangStringRestriction stringRestriction = (YangStringRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+        assertThat(stringRestriction.getDescription(), is("\"pattern description\""));
+        assertThat(stringRestriction.getReference(), is("\"pattern reference\""));
+        ListIterator<String> patternListIterator = stringRestriction.getPatternRestriction()
+                .getPatternList().listIterator();
+        assertThat(patternListIterator.next(), is("[a-zA-Z]"));
+    }
+
+    /**
+     * Checks invalid pattern sub-statement.
+     */
+    @Test(expected = ParserException.class)
+    public void processInvalidPatternSubStatements() throws IOException, ParserException {
+        YangNode node = manager.getDataModel("src/test/resources/InvalidPatternSubStatements.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PositionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PositionListenerTest.java
new file mode 100644
index 0000000..7d252ba
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PositionListenerTest.java
@@ -0,0 +1,186 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangBit;
+import org.onosproject.yangutils.datamodel.YangBits;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import java.util.Set;
+
+/**
+ * Test cases for position listener.
+ */
+public class PositionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks explicitly configured value.
+     */
+    @Test
+    public void processPositionStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("mybits"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("bits"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.BITS));
+        assertThat(((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitsName(),
+                is("mybits"));
+
+        Set<YangBit> bitSet = ((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            } else if (tmp.getBitName().equals("Ten-Mb-only")) {
+                assertThat(tmp.getPosition(), is(2));
+            }
+        }
+    }
+
+    /**
+     * Checks position value with double quotes.
+     */
+    @Test
+    public void processPositionWithDoubleQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionWithDoubleQuotes.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("mybits"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("bits"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.BITS));
+        assertThat(((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitsName(),
+                is("mybits"));
+
+        Set<YangBit> bitSet = ((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            } else if (tmp.getBitName().equals("Ten-Mb-only")) {
+                assertThat(tmp.getPosition(), is(2));
+            }
+        }
+    }
+
+    /**
+     * Checks explicit value and auto generated value.
+     */
+    @Test
+    public void processPositionImplicitAndExplicit() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionImplicitAndExplicit.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("mybits"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("bits"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.BITS));
+        assertThat(((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitsName(),
+                is("mybits"));
+
+        Set<YangBit> bitSet = ((YangBits) leafInfo.getDataType().getDataTypeExtendedInfo()).getBitSet();
+        for (YangBit tmp : bitSet) {
+            if (tmp.getBitName().equals("disable-nagle")) {
+                assertThat(tmp.getPosition(), is(0));
+            } else if (tmp.getBitName().equals("auto-sense-speed")) {
+                assertThat(tmp.getPosition(), is(1));
+            } else if (tmp.getBitName().equals("Ten-Mb-only")) {
+                assertThat(tmp.getPosition(), is(2));
+            }
+        }
+    }
+
+    /**
+     * Checks explicit value should not be repeated.
+     */
+    @Test(expected = ParserException.class)
+    public void processPositionDuplication() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionDuplication.yang");
+    }
+
+    /**
+     * Checks explicit or auto generated value should not be repeated.
+     */
+    @Test(expected = ParserException.class)
+    public void processPositionImplicitAndExplicitDuplication() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionImplicitAndExplicitDuplication.yang");
+    }
+
+    /**
+     * Checks if negative value of position is not allowed.
+     */
+    @Test(expected = ParserException.class)
+    public void processPositionNegativeValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PositionNegativeValue.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListenerTest.java
new file mode 100644
index 0000000..ef89a78
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListenerTest.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing prefix listener functionality.
+ */
+public class PrefixListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if value of prefix is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processPrefixInvalidValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixInvalidValue.yang");
+    }
+
+    /**
+     * Checks if prefix listener updates the data model tree.
+     */
+    @Test
+    public void processPrefixValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixValidEntry.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getPrefix(), is("On"));
+    }
+
+    /**
+     * Checks prefix value with double quotes.
+     */
+    @Test
+    public void processPrefixWithDoubleQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixWithDoubleQuotes.yang");
+        assertThat(((YangModule) node).getPrefix(), is("On"));
+    }
+
+    /**
+     * Checks that prefix should be present just once.
+     */
+    @Test(expected = ParserException.class)
+    public void processPrefixDualEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixDualEntry.yang");
+    }
+
+    /**
+     * Checks if prefix syntax is followed.
+     */
+    @Test(expected = ParserException.class)
+    public void processPrefixMissingValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixMissingValue.yang");
+    }
+
+    /**
+     * Checks that exception should be reported if prefix is missing.
+     */
+    @Test(expected = ParserException.class)
+    public void processPrefixOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PrefixOrder.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListenerTest.java
new file mode 100644
index 0000000..2d0e376
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListenerTest.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+/**
+ * Test cases for presence listener.
+ */
+public class PresenceListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks presence statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementPresence() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementPresence.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+        assertThat(yangContainer.getPresence(), is("\"invalid\""));
+    }
+
+    /**
+     * checks default value of presence statement.
+     */
+    @Test
+    public void processPresenceDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PresenceDefaultValue.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+        assertThat(yangContainer.getPresence(), is(nullValue()));
+    }
+
+    /**
+     * Checks presence statement without statement end.
+     */
+    @Test
+    public void processPresenceWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaf' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/PresenceWithoutStatementEnd.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java
new file mode 100644
index 0000000..0ed801f
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListenerTest.java
@@ -0,0 +1,239 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangRangeInterval;
+import org.onosproject.yangutils.datamodel.YangRangeRestriction;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.datamodel.utils.builtindatatype.YangInt32;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for range restriction listener.
+ */
+public class RangeRestrictionListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid range statement as sub-statement of leaf statement.
+     */
+    @Test
+    public void processValidRangeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidRangeStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
+
+    /**
+     * Checks valid range statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processRangeStatementInsideLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeStatementInsideLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
+
+    /**
+     * Checks valid range statement with one interval.
+     */
+    @Test
+    public void processRangeWithOneInterval() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithOneInterval.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(1));
+    }
+
+    /**
+     * Checks valid range statement with min and max.
+     */
+    @Test
+    public void processRangeWithMinMax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithMinMax.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafListInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(-2147483648));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(2147483647));
+    }
+
+    /**
+     * Checks valid range statement with invalid integer pattern.
+     */
+    @Test
+    public void processRangeWithInvalidIntegerPattern() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : Input value \"a\" is not a valid int32.");
+        YangNode node = manager.getDataModel("src/test/resources/RangeWithInvalidIntegerPattern.yang");
+    }
+
+    /**
+     * Checks valid range statement with description.
+     */
+    @Test
+    public void processRangeSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        assertThat(rangeRestriction.getDescription(), is("\"range description\""));
+        assertThat(rangeRestriction.getReference(), is("\"range reference\""));
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
+
+    /**
+     * Checks whether space can be allowed when range statement is present.
+     */
+    @Test
+    public void processRangeStatementWithSpace() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RangeStatementWithSpace.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("int32"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.INT32));
+        YangRangeRestriction rangeRestriction = (YangRangeRestriction) leafInfo
+                .getDataType().getDataTypeExtendedInfo();
+
+        ListIterator<YangRangeInterval> rangeListIterator = rangeRestriction.getAscendingRangeIntervals()
+                .listIterator();
+        YangRangeInterval rangeInterval = rangeListIterator.next();
+        assertThat(((YangInt32) rangeInterval.getStartValue()).getValue(), is(1));
+        assertThat(((YangInt32) rangeInterval.getEndValue()).getValue(), is(4));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListenerTest.java
new file mode 100644
index 0000000..17a679a
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListenerTest.java
@@ -0,0 +1,250 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for reference listener.
+ */
+public class ReferenceListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid reference statement.
+     */
+    @Test
+    public void processReferenceStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the reference is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid reference statement.
+     */
+    @Test
+    public void processReferenceWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks valid reference statement under module.
+     */
+    @Test
+    public void processModuleSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid reference statement under module.
+     */
+    @Test
+    public void processReferenceEmptyStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceEmptyStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getReference(), is("\"\""));
+    }
+
+    /**
+     * Checks valid reference statement as sub-statement of revision.
+     */
+    @Test
+    public void processRevisionSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getRevision().getReference(), is("\"revision reference\""));
+    }
+
+    /**
+     * Checks reference statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.getReference(), is("\"container reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks reference statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementReference.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and description value is set correctly.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getReference(), is("\"list reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid reference statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether description value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListenerTest.java
new file mode 100644
index 0000000..c12b377
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListenerTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing revision date listener functionality.
+ */
+public class RevisionDateListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if revision date syntax is correct in include.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionDateInvalidSyntaxAtInclude() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInvalidSyntaxAtInclude.yang");
+    }
+
+    /**
+     * Checks if revision date syntax is correct in import.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionDateInvalidSyntaxAtImport() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInvalidSyntaxAtImport.yang");
+    }
+
+    /**
+     * Checks revision date in quotes inside include.
+     */
+    @Test
+    public void processRevisionDateInQuotesAtInclude() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInQuotesAtInclude.yang");
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getRevision(), is("2015-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getRevision(), is("2014-02-03"));
+    }
+
+    /**
+     * Checks revision date in quotes inside import.
+     */
+    @Test
+    public void processRevisionDateInQuotesAtImport() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInQuotesAtImport.yang");
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getRevision(), is("2015-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getRevision(), is("2014-02-03"));
+    }
+
+    /**
+     * Checks if revision date follows YYYY-MM-DD format.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionDateInvalidFormat() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInvalidFormat.yang");
+    }
+
+    /**
+     * Checks if revision date is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionDateInvalid() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateInvalid.yang");
+    }
+
+    /**
+     * Checks if revision date listener updates the data model tree.
+     */
+    @Test
+    public void processRevisionDateValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionDateValidEntry.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getImportList().get(0).getRevision(), is("2015-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(0).getRevision(), is("2016-02-03"));
+        assertThat(((YangModule) node).getIncludeList().get(1).getRevision(), is("2014-02-03"));
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListenerTest.java
new file mode 100644
index 0000000..a5eeb04
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListenerTest.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNull.notNullValue;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing revision listener functionality.
+ */
+public class RevisionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if revision doesn't have optional parameters "revision and
+     * description".
+     */
+    @Test
+    public void processRevisionNoOptionalParameter() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionNoOptionalParameter.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getRevision().getRevDate(), is("2016-02-03"));
+    }
+
+    /**
+     * Checks if the syntax of revision is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionInValidSyntax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionInValidSyntax.yang");
+    }
+
+    /**
+     * Checks if the correct order is followed.
+     */
+    @Test(expected = ParserException.class)
+    public void processRevisionInValidOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionInValidOrder.yang");
+    }
+
+    /**
+     * Checks the revision with current date is created for empty revision statement.
+     */
+    @Test
+    public void processWithoutRevision() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionAbsence.yang");
+        assertThat(((YangModule) node).getRevision().getRevDate(), notNullValue());
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RpcListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RpcListenerTest.java
new file mode 100644
index 0000000..3af045d
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/RpcListenerTest.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangRpc;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing Rpc listener functionality.
+ */
+public class RpcListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid rpc statements.
+     */
+    @Test
+    public void processValidRpcStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidRpcStatement.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("rock"));
+
+        YangRpc yangRpc = (YangRpc) yangNode.getChild();
+        assertThat(yangRpc.getName(), is("rock-the-house"));
+        assertThat(yangRpc.getDescription(), is("\"description\""));
+        assertThat(yangRpc.getReference(), is("\"reference\""));
+        assertThat(yangRpc.getStatus(), is(YangStatusType.CURRENT));
+
+        YangTypeDef typeDef = (YangTypeDef) yangRpc.getChild();
+        assertThat(typeDef.getName(), is("my-type"));
+        assertThat(typeDef.getStatus(), is(YangStatusType.DEPRECATED));
+        assertThat(typeDef.getTypeDefBaseType().getDataType(), is(YangDataTypes.INT32));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListenerTest.java
new file mode 100644
index 0000000..132f7f4
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListenerTest.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangCase;
+import org.onosproject.yangutils.datamodel.YangChoice;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+/**
+ * Test cases for short case listener.
+ */
+public class ShortCaseListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks short case listener with container.
+     */
+    @Test
+    public void processShortCaseListenerWithContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ShortCaseListenerWithContainer.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+
+        YangCase yangCase = (YangCase) yangChoice.getChild();
+        assertThat(yangCase.getName(), is("sports-arena"));
+
+        YangContainer yangContainer1 = (YangContainer) yangCase.getChild();
+        assertThat(yangContainer1.getName(), is("sports-arena"));
+    }
+
+    /**
+     * Checks short case listener with list.
+     */
+    @Test
+    public void processShortCaseListenerWithList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ShortCaseListenerWithList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("food"));
+
+        YangChoice yangChoice = (YangChoice) yangContainer.getChild();
+        assertThat(yangChoice.getName(), is("snack"));
+
+        YangCase yangCase = (YangCase) yangChoice.getChild();
+        assertThat(yangCase.getName(), is("sports-arena"));
+
+        YangList yangList = (YangList) yangCase.getChild();
+        assertThat(yangList.getName(), is("sports-arena"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/StatusListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/StatusListenerTest.java
new file mode 100644
index 0000000..b2cbd71
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/StatusListenerTest.java
@@ -0,0 +1,288 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for status listener.
+ */
+public class StatusListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementCurrent() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementCurrent.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+    }
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementDeprecated() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementDeprecated.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.DEPRECATED));
+    }
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementObsolete() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementObsolete.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.OBSOLETE));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid status statement.
+     */
+    @Test
+    public void processStatusWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/StatusWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid status statement.
+     */
+    @Test
+    public void processStatusInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : status invalid is not valid.");
+        YangNode node = manager.getDataModel("src/test/resources/StatusInvalidValue.yang");
+    }
+
+    /**
+     * Checks status statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementStatus() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'status' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import',"
+                + " 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', 'reference', "
+                + "'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementStatus.yang");
+    }
+
+    /**
+     * Checks status statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementStatus.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether status is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+        assertThat(container.getStatus(), is(YangStatusType.OBSOLETE));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks status statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementStatus.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and status is set.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getStatus(), is(YangStatusType.CURRENT));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid status statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementStatus.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether status is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+    }
+
+    /**
+     * Checks default value of status statement.
+     */
+    @Test
+    public void processStatusDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether status is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListenerTest.java
new file mode 100644
index 0000000..6a53cbe
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListenerTest.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNull.notNullValue;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing submodule listener functionality.
+ */
+public class SubModuleListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if the sub module listeners updates the data model tree.
+     */
+    @Test
+    public void processSubModuleValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleValidEntry.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangSubModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.SUB_MODULE_NODE));
+
+        YangSubModule yangNode = (YangSubModule) node;
+        // Check whether the module name is set correctly.
+        assertThat(yangNode.getName(), is("Test"));
+        // Checks for the version value in data model tree.
+        assertThat(yangNode.getVersion(), is((byte) 1));
+        // Checks identifier of belongsto in data model tree.
+        assertThat(yangNode.getBelongsTo().getBelongsToModuleName(), is("ONOS"));
+        // Checks for the version value in data model tree.
+        assertThat(yangNode.getBelongsTo().getPrefix(), is("On1"));
+    }
+
+    /**
+     * Checks if the yang version and belongs to can come in any order in sub
+     * module.
+     */
+    @Test
+    public void processSubModuleOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleOrder.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangSubModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.SUB_MODULE_NODE));
+
+        YangSubModule yangNode = (YangSubModule) node;
+        // Check whether the module name is set correctly.
+        assertThat(yangNode.getName(), is("Test"));
+        // Checks for the version value in data model tree.
+        assertThat(yangNode.getVersion(), is((byte) 1));
+        // Checks identifier of belongsto in data model tree.
+        assertThat(yangNode.getBelongsTo().getBelongsToModuleName(), is("ONOS"));
+        // Checks for the version value in data model tree.
+        assertThat(yangNode.getBelongsTo().getPrefix(), is("On1"));
+    }
+
+    /**
+     * Checks if yang version is optional.
+     */
+    @Test
+    public void processSubModuleWithoutVersion() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleWithoutVersion.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangSubModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.SUB_MODULE_NODE));
+
+        YangSubModule yangNode = (YangSubModule) node;
+        // Check whether the module name is set correctly.
+        assertThat(yangNode.getName(), is("Test"));
+        // Checks identifier of belongsto in data model tree.
+        assertThat(yangNode.getBelongsTo().getBelongsToModuleName(), is("ONOS"));
+        // Checks for the version value in data model tree.
+        assertThat(yangNode.getBelongsTo().getPrefix(), is("On1"));
+        //Checks the revision with current date is created for empty revision statement.
+        assertThat(((YangSubModule) node).getRevision().getRevDate(), notNullValue());
+    }
+
+    /**
+     * Checks if sub module name is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processSubModuleInvalidName() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleInvalidName.yang");
+    }
+
+    /**
+     * Checks if sub module has invalid modules construct eg namespace.
+     */
+    @Test(expected = ParserException.class)
+    public void processSubModuleWithNamespace() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/SubModuleWithNamespace.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/TypeListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/TypeListenerTest.java
new file mode 100644
index 0000000..1b6a7c6
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/TypeListenerTest.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for type listener.
+ */
+public class TypeListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks derived statement without contraints.
+     */
+    @Test
+    public void processDerivedTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DerivedTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("hello"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.DERIVED));
+    }
+
+    /**
+     * Checks valid yang data type.
+     */
+    @Test
+    public void processIntegerTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IntegerTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+    }
+
+    /**
+     * Checks type for leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementType() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+    }
+
+    /**
+     * Checks for unsupported type leafref.
+     */
+    @Test
+    public void processLeafrefType() throws IOException, ParserException {
+
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"leafref\" is not supported in current version,"
+                + " please check wiki for YANG utils road map.");
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/LeafrefInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks for unsupported type identityref.
+     */
+    @Test
+    public void processIdentityrefType() throws IOException, ParserException {
+
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"identityref\" is not supported in current version,"
+                + " please check wiki for YANG utils road map.");
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/IdentityrefInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks for unsupported type instance identifier.
+     */
+    @Test
+    public void processInstanceIdentifierType() throws IOException, ParserException {
+
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : \"instance-identifier\" is not supported in current version,"
+                + " please check wiki for YANG utils road map.");
+
+        YangNode node = manager
+                .getDataModel("src/test/resources/InstanceIdentifierInvalidIdentifier.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java
new file mode 100644
index 0000000..1ac199f
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.ListIterator;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangUnion;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing union listener.
+ */
+public class UnionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks union when type is in leaf.
+     */
+    @Test
+    public void processUnionWhenTypeInLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnionWhenTypeInLeaf.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UNION));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("union"));
+
+        YangUnion yangUnion = (YangUnion) leafInfo.getDataType().getDataTypeExtendedInfo();
+
+        List<YangType<?>> typeList = yangUnion.getTypeList();
+        ListIterator<YangType<?>> typeListIterator = typeList.listIterator();
+        YangType<?> yangType = typeListIterator.next();
+
+        assertThat(yangType.getDataTypeName(), is("int32"));
+        assertThat(yangType.getDataType(), is(YangDataTypes.INT32));
+
+        YangType<?> yangTypeEnum = typeListIterator.next();
+
+        assertThat(yangTypeEnum.getDataTypeName(), is("enumeration"));
+        assertThat(yangTypeEnum.getDataType(), is(YangDataTypes.ENUMERATION));
+    }
+
+    /**
+     * Checks union when type is in leaflist.
+     */
+    @Test
+    public void processUnionWhenTypeInLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnionWhenTypeInLeafList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<YangLeafList> leafListIterator = yangList.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UNION));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("union"));
+
+        YangUnion yangUnion = (YangUnion) leafListInfo.getDataType().getDataTypeExtendedInfo();
+
+        List<YangType<?>> typeList = yangUnion.getTypeList();
+        ListIterator<YangType<?>> typeListIterator = typeList.listIterator();
+        YangType<?> yangType = typeListIterator.next();
+
+        assertThat(yangType.getDataTypeName(), is("int32"));
+        assertThat(yangType.getDataType(), is(YangDataTypes.INT32));
+
+        YangType<?> yangTypeEnum = typeListIterator.next();
+
+        assertThat(yangTypeEnum.getDataTypeName(), is("enumeration"));
+        assertThat(yangTypeEnum.getDataType(), is(YangDataTypes.ENUMERATION));
+    }
+
+    /**
+     * Checks union with empty type.
+     */
+    @Test (expected = ParserException.class)
+    public void processUnionWithEmptyType() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnionWithEmptyType.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java
new file mode 100644
index 0000000..6684df5
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java
@@ -0,0 +1,188 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.nullValue;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for units listener.
+ */
+public class UnitsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid units statement.
+     */
+    @Test
+    public void processUnitsStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether units value is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+    }
+
+    /**
+     * Checks invalid units statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementUnits() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'type' expecting {'anyxml', 'augment', 'choice', 'contact', "
+                + "'container', 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity',"
+                + " 'import', 'include', 'leaf', 'leaf-list', 'list', 'notification', 'organization', "
+                + "'reference', 'revision', 'rpc', 'typedef', 'uses', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementUnits.yang");
+    }
+
+    /**
+     * Checks invalid units statement(without statement end).
+     */
+    @Test
+    public void processUnitsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/UnitsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks order of units statement in leaf.
+     */
+    @Test
+    public void processUnitsStatementOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatementOrder.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether leaf properties is set correctly.
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("uint16"));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks the default value of unit statement.
+     */
+    @Test
+    public void processUnitsDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("invalid-interval"));
+        assertThat(leafInfo.getUnits(), is(nullValue()));
+    }
+
+    /**
+     * Checks invalid occurance of units statement as sub-statement of leaf.
+     */
+    @Test
+    public void processUnitsStatementCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error: \"units\" is defined more than once in \"leaf invalid-interval\".");
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatementCardinality.yang");
+    }
+
+    /**
+     * Checks valid units statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementUnits() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementUnits.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat(node instanceof YangModule, is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether units value is set correctly.
+        assertThat(leafListInfo.getName(), is("invalid-interval"));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UsesListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UsesListenerTest.java
new file mode 100644
index 0000000..a20c43e
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UsesListenerTest.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangUses;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing uses listener.
+ */
+public class UsesListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks uses statement inside module.
+     */
+    @Test
+    public void processUsesInModule() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UsesInModule.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangNode.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        YangUses yangUses = (YangUses) yangGrouping.getNextSibling();
+        assertThat(yangUses.getName(), is("endpoint"));
+    }
+
+    /**
+     * Checks uses statement inside container.
+     */
+    @Test
+    public void processUsesInContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UsesInContainer.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangNode.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        YangContainer yangContainer = (YangContainer) yangGrouping.getNextSibling();
+        assertThat(yangContainer.getName(), is("valid"));
+
+        YangUses yangUses = (YangUses) yangContainer.getChild();
+        assertThat(yangUses.getName(), is("endpoint"));
+
+        // Check attributes associated with uses.
+        assertThat(yangUses.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangUses.getReference(), is("\"RFC 6020\""));
+        assertThat(yangUses.getDescription(), is("\"grouping under test\""));
+    }
+
+    /**
+     * Checks uses statement inside list.
+     */
+    @Test
+    public void processUsesInList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UsesInList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        YangGrouping yangGrouping = (YangGrouping) yangNode.getChild();
+        assertThat(yangGrouping.getName(), is("endpoint"));
+
+        YangList yangList = (YangList) yangGrouping.getNextSibling();
+        assertThat(yangList.getName(), is("valid"));
+
+        YangUses yangUses = (YangUses) yangList.getChild();
+        assertThat(yangUses.getName(), is("endpoint"));
+
+        // Check attributes associated with uses.
+        assertThat(yangUses.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangUses.getReference(), is("\"RFC 6020\""));
+        assertThat(yangUses.getDescription(), is("\"grouping under test\""));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ValueListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ValueListenerTest.java
new file mode 100644
index 0000000..6dae702
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/ValueListenerTest.java
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangEnum;
+import org.onosproject.yangutils.datamodel.YangEnumeration;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import java.util.Set;
+
+/**
+ * Test cases for value listener.
+ */
+public class ValueListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks explicitly configured value.
+     */
+    @Test
+    public void processValueStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(10));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(100));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(1000));
+            }
+        }
+    }
+
+    /**
+     * Checks explicitly configured negative value.
+     */
+    @Test
+    public void processValueStatementWithNegativeValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueStatementWithNegativeValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(-2));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(-1));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(0));
+            }
+        }
+    }
+
+    /**
+     * Checks explicitly configured value with double quotes.
+     */
+    @Test
+    public void processValueStatementWithQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueStatementWithQuotes.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(10));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(100));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(1000));
+            }
+        }
+    }
+
+    /**
+     * Checks explicit value and auto generated value.
+     */
+    @Test
+    public void processValueAndAutoStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueAndAutoStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getName(), is("speed"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("enumeration"));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.ENUMERATION));
+        assertThat(((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getName(),
+                is("speed_enum"));
+
+        Set<YangEnum> enumSet = ((YangEnumeration) leafInfo.getDataType().getDataTypeExtendedInfo()).getEnumSet();
+        for (YangEnum tmp : enumSet) {
+            if (tmp.getNamedValue().equals("10m")) {
+                assertThat(tmp.getValue(), is(10));
+            } else if (tmp.getNamedValue().equals("100m")) {
+                assertThat(tmp.getValue(), is(11));
+            } else if (tmp.getNamedValue().equals("auto")) {
+                assertThat(tmp.getValue(), is(1000));
+            }
+        }
+    }
+
+    /**
+     * Checks explicit value should not be repeated.
+     */
+    @Test(expected = ParserException.class)
+    public void processValueDuplication() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueDuplication.yang");
+    }
+
+    /**
+     * Checks explicit or auto generated value should not be repeated.
+     */
+    @Test(expected = ParserException.class)
+    public void processValueExplicitAndAutoDuplication() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValueExplicitAndAutoDuplication.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/VersionListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/VersionListenerTest.java
new file mode 100644
index 0000000..3d9de83
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/listeners/VersionListenerTest.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test cases for testing version listener functionality.
+ */
+public class VersionListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks if value of version is correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processVersionInvalidValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionInvalidValue.yang");
+    }
+
+    /**
+     * Checks if version listener updates the data model tree.
+     */
+    @Test
+    public void processVersionValidEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionValidEntry.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getVersion(), is((byte) 1));
+    }
+
+    /**
+     * Checks version in double quotes.
+     */
+    @Test
+    public void processValidVersionWithDoubleQuotes() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ValidVersionWithDoubleQuotes.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getVersion(), is((byte) 1));
+    }
+
+    /**
+     * Checks if version which is optional paramater is not present.
+     */
+    @Test
+    public void processVersionNotPresent() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionNotPresent.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getVersion(), is((byte) 1));
+    }
+
+    /**
+     * Checks that version should be present only once.
+     */
+    @Test(expected = ParserException.class)
+    public void processVersionDualEntry() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionDualEntry.yang");
+    }
+
+    /**
+     * Checks if version can appear in any order in module header.
+     */
+    @Test
+    public void processVersionOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionOrder.yang");
+
+        // Checks for the version value in data model tree.
+        assertThat(((YangModule) node).getVersion(), is((byte) 1));
+    }
+
+    /**
+     * Checks if sytax of version entry is not correct.
+     */
+    @Test(expected = ParserException.class)
+    public void processVersionInvalidSyntax() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/VersionInvalidSyntax.yang");
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/AugmentListnerUtilTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/AugmentListnerUtilTest.java
new file mode 100644
index 0000000..3cf6eaa
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/AugmentListnerUtilTest.java
@@ -0,0 +1,320 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parseutils;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNodeIdentifier;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.parser.impl.parserutils.AugmentListenerUtil.clearOccurrenceCount;
+import static org.onosproject.yangutils.parser.impl.parserutils.AugmentListenerUtil.createValidNameForAugment;
+import static org.onosproject.yangutils.parser.impl.parserutils.AugmentListenerUtil.getAugmentJavaFileNameList;
+import static org.onosproject.yangutils.parser.impl.parserutils.AugmentListenerUtil.updateNameWhenHasMultipleOuccrrence;
+
+/**
+ * Unit test case for augment listener utility.
+ */
+public class AugmentListnerUtilTest {
+
+    private static final String TEST1 = "test1Node";
+    private static final String PARENT_PREFIX = "if";
+    private static final String NODE_PREFIX = "rf";
+
+    private static final String TEST1_AUGMENTED_NAME_WITHOUT_PREFIX = "AugmentedTest1Node";
+    private static final String TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI1 = "AugmentedTest1Node1";
+    private static final String TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI2 = "AugmentedTest1Node2";
+    private static final String TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI3 = "AugmentedTest1Node3";
+
+    private static final String TEST1_AUGMENTED_NAME_WITH_PREFIX = "AugmentedRfTest1Node";
+    private static final String TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI1 = "AugmentedRfTest1Node1";
+    private static final String TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI2 = "AugmentedRfTest1Node2";
+    private static final String TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI3 = "AugmentedRfTest1Node3";
+
+    private static String testString = "";
+
+    /**
+     * Unit test case when parent's prefix is present and one occurrence of augment node to update same target node.
+     */
+    @Test
+    public void testForAugmentNameWhenOneOuccrrenceWithParentPrefix() {
+        clearData();
+        testString = createValidNameForAugment(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX)));
+    }
+
+    /**
+     * Unit test case when no prefix and one occurrence of augment node to update same target node.
+     */
+    @Test
+    public void testForAugmentNameWhenOneOuccrrenceWithNoPrefix() {
+        clearData();
+        testString = createValidNameForAugment(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX)));
+    }
+
+    /**
+     * Unit test case when different prefix then parent is present and
+     * one occurrence of augment node to update same target node.
+     */
+    @Test
+    public void testForAugmentNameWhenOneOuccrrenceWithDiffPrefix() {
+        clearData();
+        testString = createValidNameForAugment(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX)));
+    }
+
+    /**
+     * Unit test case when parent's prefix is present and two occurrence of augment node to update
+     * same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenTwoOuccrrenceWithParentPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI2)));
+    }
+
+    /**
+     * Unit test case when no prefix and two occurrence of augment node to update
+     * same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenTwoOuccrrenceWithNoPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI2)));
+    }
+
+    /**
+     * Unit test case when different prefix then parent is present and
+     * two occurrence of augment node to update same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenTwoOuccrrenceWithDiffPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI2)));
+    }
+
+    /**
+     * Unit test case when parent prefix and three occurrence of augment node to update
+     * same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenThreeOuccrrenceWithParentPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Unit test case when no prefix and three occurrence of augment node to update
+     * same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenThreeOuccrrenceNoPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Unit test case when different prefix and three occurrence of augment node to update
+     * same target node is present.
+     */
+    @Test
+    public void testForAugmentNameWhenThreeOuccrrenceWithDiffPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+
+        testString = updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Unit test case for when three occurrence is there and parent prefix is present,
+     * all the names need to be updated in list.
+     */
+    @Test
+    public void testForPreviousNamesGotUpdatedWhenParentPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithParentPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithParentPrefix()));
+
+        testString = getAugmentJavaFileNameList().get(0);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI1)));
+
+        testString = getAugmentJavaFileNameList().get(1);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI2)));
+
+        testString = getAugmentJavaFileNameList().get(2);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Unit test case for when three occurrence is there and no prefix is present,
+     * all the names need to be updated in list.
+     */
+    @Test
+    public void testForPreviousNamesGotUpdatedWhenNoPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithNoPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithNoPrefix()));
+
+        testString = getAugmentJavaFileNameList().get(0);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI1)));
+
+        testString = getAugmentJavaFileNameList().get(1);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI2)));
+
+        testString = getAugmentJavaFileNameList().get(2);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITHOUT_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Unit test case for when three occurrence is there and different prefix is present,
+     * all the names need to be updated in list.
+     */
+    @Test
+    public void testForPreviousNamesGotUpdatedWhenDifferentPrefix() {
+        clearData();
+
+        createValidNameForAugment(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+        updateNameWhenHasMultipleOuccrrence(getStubNodeIdetifierWithDiffPrefix(),
+                isPrefixPresent(getStubNodeIdetifierWithDiffPrefix()));
+
+        testString = getAugmentJavaFileNameList().get(0);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI1)));
+
+        testString = getAugmentJavaFileNameList().get(1);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI2)));
+
+        testString = getAugmentJavaFileNameList().get(2);
+        assertThat(true, is(testString.equals(TEST1_AUGMENTED_NAME_WITH_PREFIX_MULTI3)));
+    }
+
+    /**
+     * Returns stub node identifier when parent prefix is used.
+     *
+     * @param name name of node
+     * @param prefix prefix of node
+     * @return node identifier for node
+     */
+    private YangNodeIdentifier getStubNodeIdetifierWithParentPrefix() {
+        YangNodeIdentifier nodeId = new YangNodeIdentifier();
+        nodeId.setName(TEST1);
+        nodeId.setPrefix(PARENT_PREFIX);
+        return nodeId;
+    }
+
+    /**
+     * Returns stub node identifier when no prefix is used.
+     *
+     * @param name name of node
+     * @param prefix prefix of node
+     * @return node identifier for node
+     */
+    private YangNodeIdentifier getStubNodeIdetifierWithNoPrefix() {
+        YangNodeIdentifier nodeId = new YangNodeIdentifier();
+        nodeId.setName(TEST1);
+        nodeId.setPrefix(null);
+        return nodeId;
+    }
+
+    /**
+     * Returns stub node identifier when different prefix is used.
+     *
+     * @param name name of node
+     * @param prefix prefix of node
+     * @return node identifier for node
+     */
+    private YangNodeIdentifier getStubNodeIdetifierWithDiffPrefix() {
+        YangNodeIdentifier nodeId = new YangNodeIdentifier();
+        nodeId.setName(TEST1);
+        nodeId.setPrefix(NODE_PREFIX);
+        return nodeId;
+    }
+
+    /**
+     * Returns true if a prefix is present and it is not equals to parents prefix.
+     *
+     * @param nodeId YANG node identifier
+     * @param parentsPrefix parent's prefix
+     * @return true if a prefix is present and it is not equals to parents prefix
+     */
+    private static boolean isPrefixPresent(YangNodeIdentifier nodeId) {
+        return nodeId.getPrefix() != null && nodeId.getPrefix() != PARENT_PREFIX;
+    }
+
+    /**
+     * Clears list of names and occurrence count after each test case.
+     */
+    private void clearData() {
+        getAugmentJavaFileNameList().clear();
+        clearOccurrenceCount();
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerErrorMessageConstructionTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerErrorMessageConstructionTest.java
new file mode 100644
index 0000000..bcfaf20
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerErrorMessageConstructionTest.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parseutils;
+
+import org.junit.Test;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.CONTACT_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+
+/**
+ * Test case for testing listener error message construction util.
+ */
+public class ListenerErrorMessageConstructionTest {
+
+    /**
+     * Checks for error message construction with parsable data type name.
+     */
+    @Test
+    public void checkErrorMsgConstructionWithName() {
+
+        // Create an test error message
+        String testErrorMessage = constructListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA, "Test Instance", ENTRY);
+
+        // Check message.
+        assertThat(testErrorMessage, is("Internal parser error detected: Invalid holder for contact "
+                + "\"Test Instance\" before processing."));
+    }
+
+    /**
+     * Checks for error message construction without parsable data type name.
+     */
+    @Test
+    public void checkErrorMsgConstructionWithoutName() {
+
+        // Create an test error message
+        String testErrorMessage = constructListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA, "Test Instance", ENTRY);
+
+        // Check message.
+        assertThat(testErrorMessage,
+                   is("Internal parser error detected: Invalid holder for contact \"Test Instance\""
+                           + " before processing."));
+    }
+
+    /**
+     * Checks for extended error message construction with parsable data type
+     * name.
+     */
+    @Test
+    public void checkExtendedErrorMsgConstructionWithName() {
+
+        // Create an test error message
+        String testErrorMessage = constructExtendedListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA,
+                                                                        "Test Instance", ENTRY,
+                                                                        "Extended Information");
+
+        // Check message.
+        assertThat(testErrorMessage,
+                   is("Internal parser error detected: Invalid holder for contact \"Test Instance\""
+                           + " before processing.\n" + "Error Information: Extended Information"));
+    }
+
+    /**
+     * Checks for extended error message construction without parsable data type
+     * name.
+     */
+    @Test
+    public void checkExtendedErrorMsgConstructionWithoutName() {
+
+        // Create an test error message
+        String testErrorMessage = constructExtendedListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA, "", ENTRY,
+                                                                        "Extended Information");
+
+        // Check message.
+        assertThat(testErrorMessage, is("Internal parser error detected: Invalid holder for contact"
+                + " before processing.\n" + "Error Information: Extended Information"));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerUtilTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerUtilTest.java
new file mode 100644
index 0000000..c29b126
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerUtilTest.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parseutils;
+
+import java.io.IOException;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+/**
+ * Test case for testing listener util.
+ */
+public class ListenerUtilTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks whether exception is thrown when identifier starts with xml.
+     */
+    @Test
+    public void validateIdentifierStartsWithXml() throws IOException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("YANG file error : module identifier xMlTest must not start" +
+                " with (('X'|'x') ('M'|'m') ('L'|'l'))");
+        manager.getDataModel("src/test/resources/InValidIdentifierXML.yang");
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerValidationTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerValidationTest.java
new file mode 100644
index 0000000..ce347d6
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ListenerValidationTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parseutils;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangRevision;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.YANGBASE_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsEmpty;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+
+/**
+ * Test case for testing listener validation util.
+ */
+public class ListenerValidationTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Checks for exception in case parsable stack is empty while validating for
+     * not empty scenario.
+     */
+    @Test
+    public void validateStackIsNotEmptyForEmptyStack() {
+
+        String expectedError = constructListenerErrorMessage(MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+
+        // Get the exception occurred during parsing.
+        thrown.expect(ParserException.class);
+        thrown.expectMessage(expectedError);
+
+        // Create test walker and assign test error to it.
+        TreeWalkListener testWalker = new TreeWalkListener();
+
+        checkStackIsNotEmpty(testWalker, MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+    }
+
+    /**
+     * Checks if there is no exception in case parsable stack is not empty while
+     * validating for not empty scenario.
+     */
+    @Test
+    public void validateStackIsNotEmptyForNonEmptyStack() {
+
+        // Create test walker and assign test error to it.
+        TreeWalkListener testWalker = new TreeWalkListener();
+
+        // Create a temporary node of parsable.
+        YangRevision tmpNode = new YangRevision();
+        testWalker.getParsedDataStack().push(tmpNode);
+
+        checkStackIsNotEmpty(testWalker, MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+    }
+
+    /**
+     * Checks for exception in case parsable stack is not empty while validating
+     * for empty scenario.
+     */
+    @Test
+    public void validateStackIsEmptyForNonEmptyStack() {
+
+        String expectedError = constructListenerErrorMessage(MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+
+        // Get the exception occurred during parsing.
+        thrown.expect(ParserException.class);
+        thrown.expectMessage(expectedError);
+
+        // Create test walker and assign test error to it.
+        TreeWalkListener testWalker = new TreeWalkListener();
+
+        // Create a temporary node of parsable.
+        YangRevision tmpNode = new YangRevision();
+        testWalker.getParsedDataStack().push(tmpNode);
+
+        checkStackIsEmpty(testWalker, MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+    }
+
+    /**
+     * Checks if there is no exception in case parsable stack is empty while
+     * validating for empty scenario.
+     */
+    @Test
+    public void validateStackIsEmptyForEmptyStack() {
+
+        // Create test walker and assign test error to it.
+        TreeWalkListener testWalker = new TreeWalkListener();
+
+        checkStackIsEmpty(testWalker, MISSING_HOLDER, YANGBASE_DATA, "", EXIT);
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ParseTreeErrorListenerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ParseTreeErrorListenerTest.java
new file mode 100644
index 0000000..4489e77
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/parser/impl/parseutils/ParseTreeErrorListenerTest.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parseutils;
+
+import org.antlr.v4.runtime.ANTLRFileStream;
+import org.antlr.v4.runtime.ANTLRInputStream;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.tree.ParseTree;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangLexer;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.CustomExceptionMatcher;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+import org.onosproject.yangutils.parser.impl.parserutils.ParseTreeErrorListener;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Test case for testing parse tree error listener.
+ */
+public class ParseTreeErrorListenerTest {
+
+    YangUtilsParserManager manager = new YangUtilsParserManager();
+    File file;
+    BufferedWriter out;
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Checks that no exception is generated for YANG file with valid syntax.
+     */
+    @Test
+    public void checkValidYangFileForNoSyntaxError() throws IOException {
+
+        ANTLRInputStream input = new ANTLRFileStream("src/test/resources/YangFileWithoutSyntaxError.yang");
+
+        // Create a lexer that feeds off of input char stream.
+        GeneratedYangLexer lexer = new GeneratedYangLexer(input);
+        // Create a buffer of tokens pulled from the lexer.
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        // Create a parser that feeds off the tokens buffer.
+        GeneratedYangParser parser = new GeneratedYangParser(tokens);
+        // Remove console error listener.
+        parser.removeErrorListeners();
+        // Create instance of customized error listener.
+        ParseTreeErrorListener parseTreeErrorListener = new ParseTreeErrorListener();
+        // Add customized error listener to catch errors during parsing.
+        parser.addErrorListener(parseTreeErrorListener);
+        // Begin parsing YANG file and generate parse tree.
+        ParseTree tree = parser.yangfile();
+    }
+
+    /**
+     * Checks that exception is generated for YANG file with invalid syntax.
+     */
+    @Test
+    public void checkInvalidYangFileForSyntaxError() throws IOException {
+
+        // Get the exception occurred during parsing.
+        thrown.expect(ParserException.class);
+        thrown.expect(CustomExceptionMatcher.errorLocation(3, 0));
+        thrown.expectMessage("no viable alternative at input 'yang-version 1\\nnamespace'");
+
+        ANTLRInputStream input = new ANTLRFileStream("src/test/resources/YangFileWithSyntaxError.yang");
+
+        // Create a lexer that feeds off of input char stream.
+        GeneratedYangLexer lexer = new GeneratedYangLexer(input);
+        // Create a buffer of tokens pulled from the lexer.
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        // Create a parser that feeds off the tokens buffer.
+        GeneratedYangParser parser = new GeneratedYangParser(tokens);
+        // Remove console error listener.
+        parser.removeErrorListeners();
+        // Create instance of customized error listener.
+        ParseTreeErrorListener parseTreeErrorListener = new ParseTreeErrorListener();
+        // Add customized error listener to catch errors during parsing.
+        parser.addErrorListener(parseTreeErrorListener);
+        // Begin parsing YANG file and generate parse tree.
+        ParseTree tree = parser.yangfile();
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/AttributesJavaDataTypeTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/AttributesJavaDataTypeTest.java
new file mode 100644
index 0000000..f2ca36e
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/AttributesJavaDataTypeTest.java
@@ -0,0 +1,203 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangDerivedInfo;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.translator.tojava.JavaFileInfo;
+import org.onosproject.yangutils.translator.tojava.javamodel.YangJavaModule;
+import org.onosproject.yangutils.translator.tojava.javamodel.YangJavaTypeDef;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.BOOLEAN;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.DERIVED;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.INT32;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.UINT8;
+import static org.onosproject.yangutils.translator.tojava.utils.AttributesJavaDataType.getJavaDataType;
+import static org.onosproject.yangutils.translator.tojava.utils.AttributesJavaDataType.getJavaImportClass;
+import static org.onosproject.yangutils.translator.tojava.utils.AttributesJavaDataType.getJavaImportPackage;
+import static org.onosproject.yangutils.utils.UtilConstants.JAVA_LANG;
+
+/**
+ * Unit test case for attribute java data type.
+ */
+public class AttributesJavaDataTypeTest {
+
+    private static final YangDataTypes TYPE1 = STRING;
+    private static final YangDataTypes TYPE2 = INT32;
+    private static final YangDataTypes TYPE3 = BOOLEAN;
+    private static final YangDataTypes TYPE4 = UINT8;
+    private static final YangDataTypes TYPE_DEF = DERIVED;
+    private static final String CLASS_INFO1 = "String";
+    private static final String CLASS_INFO2 = "int";
+    private static final String CLASS_INFO3 = "boolean";
+    private static final String CLASS_INFO4 = "short";
+    private static final String CLASS_INFO5 = "Integer";
+    private static final String TYPE_DEF_PKG = "target.test";
+    private static String test = "";
+    private static YangToJavaNamingConflictUtil pluginConfig = null;
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {AttributesJavaDataType.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * Unit test for java class info method test.
+     */
+    @Test
+    public void testgetJavaClassInfo() {
+        test = getJavaImportClass(getStubYangType(TYPE1), false, pluginConfig);
+        assertThat(true, is(test.equals(CLASS_INFO1)));
+
+        test = getJavaImportClass(getStubYangType(TYPE2), true, pluginConfig);
+        assertThat(true, is(test.equals(CLASS_INFO5)));
+
+        test = getJavaImportClass(getStubYangType(TYPE3), false, pluginConfig);
+        assertThat(null, is(test));
+
+        test = getJavaImportClass(getStubYangType(TYPE4), false, pluginConfig);
+        assertThat(null, is(test));
+    }
+
+    /**
+     * Unit test for java data type method.
+     */
+    @Test
+    public void testgetJavaDataType() {
+        test = getJavaDataType(getStubYangType(TYPE1));
+        assertThat(true, is(test.equals(CLASS_INFO1)));
+
+        test = getJavaDataType(getStubYangType(TYPE2));
+        assertThat(true, is(test.equals(CLASS_INFO2)));
+
+        test = getJavaDataType(getStubYangType(TYPE3));
+        assertThat(true, is(test.equals(CLASS_INFO3)));
+
+        test = getJavaDataType(getStubYangType(TYPE4));
+        assertThat(true, is(test.equals(CLASS_INFO4)));
+    }
+
+    /**
+     * Unit test for java package info method.
+     */
+    @Test
+    public void testgetJavaPkgInfo() {
+        test = getJavaImportPackage(getStubYangType(TYPE1), false, pluginConfig);
+        assertThat(true, is(test.equals(JAVA_LANG)));
+
+        test = getJavaImportPackage(getStubYangType(TYPE2), true, pluginConfig);
+        assertThat(true, is(test.equals(JAVA_LANG)));
+
+        test = getJavaImportPackage(getStubYangType(TYPE3), false, pluginConfig);
+        assertThat(null, is(test));
+
+        test = getJavaImportPackage(getStubYangType(TYPE4), false, pluginConfig);
+        assertThat(null, is(test));
+    }
+
+    /**
+     * Unit test case for typedef.
+     *
+     * @throws DataModelException when fails to do data model operations
+     */
+    @Test
+    public void testForTypeDef() throws DataModelException {
+        test = getJavaImportPackage(getStubExtendedInfo(getStubYangType(TYPE_DEF)), false, pluginConfig);
+        assertThat(true, is(test.equals(TYPE_DEF_PKG)));
+    }
+
+    /**
+     * Returns stub YANG type for test.
+     *
+     * @param dataTypes YANG data types
+     * @return YANG type
+     */
+    private YangType<?> getStubYangType(YangDataTypes dataTypes) {
+        YangType<?> type = new YangType<>();
+        type.setDataType(dataTypes);
+        return type;
+    }
+
+    /**
+     * Returns YANG type with extended info.
+     *
+     * @param type YANG type
+     * @return YANG type with extended info
+     * @throws DataModelException when fails to do data model operations
+     */
+    @SuppressWarnings("unchecked")
+    private YangType<?> getStubExtendedInfo(YangType<?> type) throws DataModelException {
+        YangJavaTypeDef typedef = new YangJavaTypeDef();
+        getStubParent().addChild(typedef);
+        YangDerivedInfo<?> derInfo = new YangDerivedInfo<>();
+        derInfo.setReferredTypeDef(typedef);
+        ((YangType<YangDerivedInfo<?>>) type).setDataTypeExtendedInfo(derInfo);
+        return type;
+    }
+
+    /**
+     * Returns java file info.
+     *
+     * @return java file info
+     */
+    private JavaFileInfo addStubJavaFileInfo() {
+        JavaFileInfo fileInfo = new JavaFileInfo();
+        fileInfo.setJavaName("test");
+        fileInfo.setPackage("target");
+        return fileInfo;
+    }
+
+    /**
+     * Adds stub parent module for typedef.
+     *
+     * @return stub parent module
+     */
+    private YangNode getStubParent() {
+        YangJavaModule parent = new YangJavaModule();
+        parent.setJavaFileInfo(addStubJavaFileInfo());
+        return parent;
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ChoiceCaseTranslatorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ChoiceCaseTranslatorTest.java
new file mode 100644
index 0000000..74043f6
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ChoiceCaseTranslatorTest.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Unit tests for choice-case translator.
+ */
+public final class ChoiceCaseTranslatorTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks choice-case translation should not result in any exception.
+     */
+    @Test
+    public void processChoiceCaseTranslator() throws IOException, ParserException {
+
+        String userDir = System.getProperty("user.dir");
+        YangNode node = manager.getDataModel("src/test/resources/ChoiceCaseTranslator.yang");
+
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir(userDir + "/target/ChoiceCaseTestGenFile/");
+
+        generateJavaCode(node, yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/ChoiceCaseTestGenFile/");
+    }
+    // TODO enhance the test cases, after having a framework of translator test.
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java
new file mode 100644
index 0000000..39d5205
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/ClassDefinitionGeneratorTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.translator.tojava.GeneratedJavaFileType.BUILDER_CLASS_MASK;
+import static org.onosproject.yangutils.translator.tojava.GeneratedJavaFileType.BUILDER_INTERFACE_MASK;
+import static org.onosproject.yangutils.translator.tojava.GeneratedJavaFileType.GENERATE_TYPEDEF_CLASS;
+import static org.onosproject.yangutils.translator.tojava.GeneratedJavaFileType.IMPL_CLASS_MASK;
+import static org.onosproject.yangutils.translator.tojava.utils.ClassDefinitionGenerator.generateClassDefinition;
+
+/**
+ * Unit tests for class definition generator for generated files.
+ */
+public final class ClassDefinitionGeneratorTest {
+
+    private static final String CLASS_NAME = "TestClass";
+    private static final String INTERFACE_CLASS_DEF = "public interface TestClass {\n";
+    private static final String BULDER_INTERFACE_CLASS_DEF = "interface TestClassBuilder {\n\n";
+    private static final String BUILDER_CLASS_DEF = "public class TestClassBuilder implements "
+            + "TestClass.TestClassBuilder {\n";
+    private static final String IMPL_CLASS_DEF = "public final class TestClassImpl implements TestClass {\n";
+    private static final String TYPE_DEF_CLASS_DEF = "public final class TestClass {\n";
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {ClassDefinitionGenerator.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * Unit test for builder class definition.
+     */
+    @Test
+    public void generateBuilderClassDefinitionTest() {
+        String builderClassDefinition = generateClassDefinition(BUILDER_CLASS_MASK, CLASS_NAME);
+        assertThat(true, is(builderClassDefinition.equals(BUILDER_CLASS_DEF)));
+    }
+
+    /**
+     * Unit test for builder interface definition.
+     */
+    @Test
+    public void generateBuilderInterfaceDefinitionTest() {
+        String builderInterfaceDefinition = generateClassDefinition(BUILDER_INTERFACE_MASK, CLASS_NAME);
+        assertThat(true, is(builderInterfaceDefinition.equals(BULDER_INTERFACE_CLASS_DEF)));
+    }
+
+    /**
+     * Unit test for impl class definition.
+     */
+    @Test
+    public void generateImplDefinitionTest() {
+        String implDefinition = generateClassDefinition(IMPL_CLASS_MASK, CLASS_NAME);
+        assertThat(true, is(implDefinition.equals(IMPL_CLASS_DEF)));
+    }
+
+    /**
+     * Unit test for interface definition.
+     */
+    @Test
+    public void generateinterfaceDefinitionTest() {
+        // TODO: need to add this test case.
+    }
+
+    /**
+     * Unit test for typedef generated type.
+     */
+    @Test
+    public void generateTypeDefTest() {
+        String typeDef = generateClassDefinition(GENERATE_TYPEDEF_CLASS, CLASS_NAME);
+        assertThat(true, is(typeDef.equals(TYPE_DEF_CLASS_DEF)));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/EnumTranslatorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/EnumTranslatorTest.java
new file mode 100644
index 0000000..2a950fc
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/EnumTranslatorTest.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Unit test case for enum translator.
+ */
+public final class EnumTranslatorTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks enum translation should not result in any exception.
+     */
+    @Test
+    public void processEnumTranslator()
+            throws IOException, ParserException {
+
+        String userDir = System.getProperty("user.dir");
+        YangNode node = manager.getDataModel("src/test/resources/EnumTranslator.yang");
+
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir(userDir + "/target/EnumTestGenFile/");
+
+        generateJavaCode(node, yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/EnumTestGenFile/");
+    }
+    // TODO enhance the test cases, after having a framework of translator test.
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaCodeSnippetGenTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaCodeSnippetGenTest.java
new file mode 100644
index 0000000..fd5c0d3
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaCodeSnippetGenTest.java
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.translator.tojava.JavaQualifiedTypeInfo;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaCodeSnippetGen.getImportText;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaCodeSnippetGen.getJavaAttributeDefination;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaCodeSnippetGen.getJavaClassDefClose;
+import static org.onosproject.yangutils.utils.UtilConstants.CLOSE_CURLY_BRACKET;
+import static org.onosproject.yangutils.utils.UtilConstants.DIAMOND_CLOSE_BRACKET;
+import static org.onosproject.yangutils.utils.UtilConstants.DIAMOND_OPEN_BRACKET;
+import static org.onosproject.yangutils.utils.UtilConstants.IMPORT;
+import static org.onosproject.yangutils.utils.UtilConstants.JAVA_LANG;
+import static org.onosproject.yangutils.utils.UtilConstants.LIST;
+import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
+import static org.onosproject.yangutils.utils.UtilConstants.PERIOD;
+import static org.onosproject.yangutils.utils.UtilConstants.PRIVATE;
+import static org.onosproject.yangutils.utils.UtilConstants.SEMI_COLAN;
+import static org.onosproject.yangutils.utils.UtilConstants.SPACE;
+import static org.onosproject.yangutils.utils.UtilConstants.STRING_DATA_TYPE;
+
+/**
+ * Unit test cases for java code snippet generator.
+ */
+public class JavaCodeSnippetGenTest {
+
+    private static final String PKG_INFO = "org.onosproject.unittest";
+    private static final String CLASS_INFO = "JavaCodeSnippetGenTest";
+    private static final String YANG_NAME = "Test";
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {JavaCodeSnippetGen.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * Unit test case for import text.
+     */
+    @Test
+    public void testForImportText() {
+        JavaQualifiedTypeInfo importInfo = new JavaQualifiedTypeInfo();
+        importInfo.setPkgInfo(PKG_INFO);
+        importInfo.setClassInfo(CLASS_INFO);
+
+        String imports = getImportText(importInfo);
+
+        assertThat(true, is(imports.equals(IMPORT + PKG_INFO + PERIOD + CLASS_INFO + SEMI_COLAN + NEW_LINE)));
+    }
+
+    /**
+     * Unit test case for java class interface definition close.
+     */
+    @Test
+    public void testForJavaClassDefClose() {
+        String interfaceDef = getJavaClassDefClose();
+        assertThat(true, is(interfaceDef.equals(CLOSE_CURLY_BRACKET)));
+    }
+
+    /**
+     * Unit test case for java attribute info.
+     */
+    @Test
+    public void testForJavaAttributeInfo() {
+
+        String attributeWithoutTypePkg = getJavaAttributeDefination(null, STRING_DATA_TYPE, YANG_NAME, false);
+        assertThat(true, is(attributeWithoutTypePkg.equals(
+                PRIVATE + SPACE + STRING_DATA_TYPE + SPACE + YANG_NAME + SEMI_COLAN + NEW_LINE)));
+
+        String attributeWithTypePkg = getJavaAttributeDefination(JAVA_LANG, STRING_DATA_TYPE, YANG_NAME, false);
+        assertThat(true, is(attributeWithTypePkg.equals(PRIVATE + SPACE + JAVA_LANG + PERIOD
+                + STRING_DATA_TYPE + SPACE + YANG_NAME + SEMI_COLAN + NEW_LINE)));
+
+        String attributeWithListPkg = getJavaAttributeDefination(JAVA_LANG, STRING_DATA_TYPE, YANG_NAME, true);
+        assertThat(true, is(attributeWithListPkg.equals(
+                PRIVATE + SPACE + LIST + DIAMOND_OPEN_BRACKET + JAVA_LANG + PERIOD + STRING_DATA_TYPE
+                        + DIAMOND_CLOSE_BRACKET + SPACE + YANG_NAME + SEMI_COLAN + NEW_LINE)));
+
+        String attributeWithListWithoutPkg = getJavaAttributeDefination(null, STRING_DATA_TYPE, YANG_NAME, true);
+        assertThat(true, is(attributeWithListWithoutPkg.equals(
+                PRIVATE + SPACE + LIST + DIAMOND_OPEN_BRACKET + STRING_DATA_TYPE + DIAMOND_CLOSE_BRACKET + SPACE
+                        + YANG_NAME + SEMI_COLAN + NEW_LINE)));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntaxTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntaxTest.java
new file mode 100644
index 0000000..6b86b9c
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/JavaIdentifierSyntaxTest.java
@@ -0,0 +1,284 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.translator.exception.TranslatorException;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getCamelCase;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getCapitalCase;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getJavaPackageFromPackagePath;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getPackageDirPathFromJavaJPackage;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getRootPackage;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getSmallCase;
+import static org.onosproject.yangutils.utils.UtilConstants.DEFAULT_BASE_PKG;
+import static org.onosproject.yangutils.utils.UtilConstants.PERIOD;
+
+/**
+ * Unit tests for java identifier syntax.
+ */
+public final class JavaIdentifierSyntaxTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private static final String PARENT_PACKAGE = "test5/test6/test7";
+    private static final String CHILD_PACKAGE = "test1:test2:test3";
+    private static final String DATE1 = "2000-1-5";
+    private static final String DATE2 = "1992-01-25";
+    private static final String PARENT_WITH_PERIOD = "test5.test6.test7";
+    private static final String CHILD_WITH_PERIOD = "test1.test2.test3";
+    private static final String DATE_WITH_REV1 = "rev20000105";
+    private static final String DATE_WITH_REV2 = "rev19920125";
+    private static final String VERSION_NUMBER = "v1";
+    private static final String VALID_PREFIX = "123add-prefix";
+    private static final String INVALID_PREFIX = "-*()&^&#$%";
+    private static final String INVALID_PREFIX1 = "abc~!@#$%^&*()_+}{:<>?`1234567890-=[]''|,./SS";
+    private static final String INVALID_NAME_SPACE_FOR_INVALID_PREFIX = "try:#test3:9case3";
+    private static final String INVALID_NAME_SPACE1 = "byte:#test2:9test3";
+    private static final String INVALID_NAME_SPACE2 = "const:#test2://9test3";
+    private static final String INVALID_NAME_SPACE3 = "CONST:TRY://9test3";
+    private static final String VALID_NAME_SPACE1 = "123addprefixbyte.test2.123addprefix9test3";
+    private static final String VALID_NAME_SPACE2 = "yangautoprefixconst.test2.yangautoprefix9test3";
+    private static final String VALID_NAME_SPACE3 = "abc1234567890ssconst.test2.abc1234567890ss9test3";
+    private static final String VALID_NAME_SPACE4 = "yangautoprefixconst.yangautoprefixtry.yangautoprefix9test3";
+    private static final String WITHOUT_CAMEL_CASE = "test-camel-case-identifier";
+    private static final String WITH_CAMEL_CASE = "testCamelCaseIdentifier";
+    private static final String WITHOUT_CAMEL_CASE1 = ".-_try-._-.123";
+    private static final String WITH_CAMEL_CASE1 = "try123";
+    private static final String WITHOUT_CAMEL_CASE2 = "_try";
+    private static final String WITH_CAMEL_CASE2 = "yangAutoPrefixTry";
+    private static final String WITHOUT_CAMEL_CASE3 = "-1-123g-123ga-a";
+    private static final String WITH_CAMEL_CASE3 = "yangAutoPrefix1123G123Gaa";
+    private static final String WITHOUT_CAMEL_CASE4 = "a-b-c-d-e-f-g-h";
+    private static final String WITH_CAMEL_CASE4 = "aBcDeFgh";
+    private static final String WITHOUT_CAMEL_CASE5 = "TestName";
+    private static final String WITH_CAMEL_CASE5 = "testName";
+    private static final String WITHOUT_CAMEL_CASE6 = "TEST-NAME";
+    private static final String WITH_CAMEL_CASE6 = "testName";
+    private static final String WITHOUT_CAMEL_CASE7 = "TESTNAME";
+    private static final String WITH_CAMEL_CASE7 = "testname";
+    private static final String WITHOUT_CAMEL_CASE8 = "TE-ST-NA-ME";
+    private static final String WITH_CAMEL_CASE8 = "teStNaMe";
+    private static final String WITHOUT_CAMEL_CASE9 = "TEST3NAME";
+    private static final String WITH_CAMEL_CASE9 = "test3Name";
+    private static final String WITHOUT_CAMEL_CASE10 = "TEST3";
+    private static final String WITH_CAMEL_CASE10 = "test3";
+    private static final String WITHOUT_CAMEL_CASE11 = "TEST3nAMe";
+    private static final String WITH_CAMEL_CASE11 = "test3Name";
+    private static final String WITHOUT_CAMEL_CASE12 = "TEST3name";
+    private static final String WITH_CAMEL_CASE12 = "test3Name";
+    private static final String WITHOUT_CAMEL_CASE13 = "t-RY";
+    private static final String WITH_CAMEL_CASE13 = "tRy";
+    private static final String WITHOUT_CAMEL_CASE14 = "TRY";
+    private static final String WITH_CAMEL_CASE14 = "yangAutoPrefixTry";
+    private static final String WITHOUT_CAPITAL = "test_this";
+    private static final String WITH_CAPITAL = "Test_this";
+    private static final String WITH_SMALL = "test_this";
+    private static final String WITH_CAMEL_CASE_WITH_PREFIX = "123addPrefixTry";
+    private static final String WITH_CAMEL_CASE_WITH_PREFIX1 = "abc1234567890Ss1123G123Gaa";
+    private static YangToJavaNamingConflictUtil conflictResolver = new YangToJavaNamingConflictUtil();
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException if any security violation is observed.
+     * @throws NoSuchMethodException if when the method is not found.
+     * @throws IllegalArgumentException if there is illegal argument found.
+     * @throws InstantiationException if instantiation is provoked for the
+     *             private constructor.
+     * @throws IllegalAccessException if instance is provoked or a method is
+     *             provoked.
+     * @throws InvocationTargetException when an exception occurs by the method
+     *             or constructor.
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {JavaIdentifierSyntax.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * Unit test for root package generation with revision complexity.
+     */
+    @Test
+    public void getRootPackageTest() {
+        conflictResolver.setPrefixForIdentifier(null);
+        String rootPackage = getRootPackage((byte) 1, CHILD_PACKAGE, DATE1, conflictResolver);
+        assertThat(rootPackage.equals(DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER
+                + PERIOD + CHILD_WITH_PERIOD + PERIOD + DATE_WITH_REV1), is(true));
+    }
+
+    /**
+     * Unit test for root package generation with invalid prefix.
+     */
+    @Test
+    public void getRootPackageWithInvalidPrefix() throws TranslatorException {
+        thrown.expect(TranslatorException.class);
+        thrown.expectMessage("The given prefix in pom.xml is invalid.");
+        conflictResolver.setPrefixForIdentifier(INVALID_PREFIX);
+        String rootPackage1 = getRootPackage((byte) 1, INVALID_NAME_SPACE_FOR_INVALID_PREFIX, DATE1, conflictResolver);
+    }
+
+    /**
+     * Unit test for root package generation with special characters presence.
+     */
+    @Test
+    public void getRootPackageWithSpecialCharactersTest() {
+        conflictResolver.setPrefixForIdentifier(VALID_PREFIX);
+        String rootPackage = getRootPackage((byte) 1, INVALID_NAME_SPACE1, DATE1, conflictResolver);
+        assertThat(rootPackage.equals(DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER
+                + PERIOD + VALID_NAME_SPACE1 + PERIOD + DATE_WITH_REV1), is(true));
+        conflictResolver.setPrefixForIdentifier(null);
+        String rootPackage1 = getRootPackage((byte) 1, INVALID_NAME_SPACE2, DATE1, conflictResolver);
+        assertThat(rootPackage1.equals(DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER
+                + PERIOD + VALID_NAME_SPACE2 + PERIOD + DATE_WITH_REV1), is(true));
+        String rootPackage2 = getRootPackage((byte) 1, INVALID_NAME_SPACE3, DATE1, conflictResolver);
+        assertThat(rootPackage2.equals(DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER
+                + PERIOD + VALID_NAME_SPACE4 + PERIOD + DATE_WITH_REV1), is(true));
+        conflictResolver.setPrefixForIdentifier(INVALID_PREFIX1);
+        String rootPackage3 = getRootPackage((byte) 1, INVALID_NAME_SPACE2, DATE1, conflictResolver);
+        assertThat(rootPackage3.equals(DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER
+                + PERIOD + VALID_NAME_SPACE3 + PERIOD + DATE_WITH_REV1), is(true));
+
+    }
+
+    /**
+     * Unit test for root package generation without complexity in revision.
+     */
+    @Test
+    public void getRootPackageWithRevTest() {
+        String rootPkgWithRev = getRootPackage((byte) 1, CHILD_PACKAGE, DATE2, null);
+        assertThat(rootPkgWithRev.equals(
+                DEFAULT_BASE_PKG + PERIOD + VERSION_NUMBER + PERIOD + CHILD_WITH_PERIOD + PERIOD + DATE_WITH_REV2),
+                is(true));
+    }
+
+    /**
+     * Unit test for capitalizing the incoming string.
+     */
+    @Test
+    public void getCapitalCaseTest() {
+        String capitalCase = getCapitalCase(WITHOUT_CAPITAL);
+        assertThat(capitalCase.equals(WITH_CAPITAL), is(true));
+    }
+
+    /**
+     * Unit test for getting the camel case for the received string.
+     */
+    @Test
+    public void getCamelCaseTest() {
+        conflictResolver.setPrefixForIdentifier(null);
+        String camelCase = getCamelCase(WITHOUT_CAMEL_CASE, conflictResolver);
+        assertThat(camelCase.equals(WITH_CAMEL_CASE), is(true));
+        String camelCase1 = getCamelCase(WITHOUT_CAMEL_CASE1, conflictResolver);
+        assertThat(camelCase1.equals(WITH_CAMEL_CASE1), is(true));
+        String camelCase2 = getCamelCase(WITHOUT_CAMEL_CASE2, conflictResolver);
+        assertThat(camelCase2.equals(WITH_CAMEL_CASE2), is(true));
+        String camelCase3 = getCamelCase(WITHOUT_CAMEL_CASE3, conflictResolver);
+        assertThat(camelCase3.equals(WITH_CAMEL_CASE3), is(true));
+        String camelCase4 = getCamelCase(WITHOUT_CAMEL_CASE4, conflictResolver);
+        assertThat(camelCase4.equals(WITH_CAMEL_CASE4), is(true));
+        String camelCase5 = getCamelCase(WITHOUT_CAMEL_CASE5, conflictResolver);
+        assertThat(camelCase5.equals(WITH_CAMEL_CASE5), is(true));
+        String camelCase6 = getCamelCase(WITHOUT_CAMEL_CASE6, conflictResolver);
+        assertThat(camelCase6.equals(WITH_CAMEL_CASE6), is(true));
+        String camelCase7 = getCamelCase(WITHOUT_CAMEL_CASE7, conflictResolver);
+        assertThat(camelCase7.equals(WITH_CAMEL_CASE7), is(true));
+        String camelCase8 = getCamelCase(WITHOUT_CAMEL_CASE8, conflictResolver);
+        assertThat(camelCase8.equals(WITH_CAMEL_CASE8), is(true));
+        String camelCase9 = getCamelCase(WITHOUT_CAMEL_CASE9, conflictResolver);
+        assertThat(camelCase9.equals(WITH_CAMEL_CASE9), is(true));
+        String camelCase10 = getCamelCase(WITHOUT_CAMEL_CASE10, conflictResolver);
+        assertThat(camelCase10.equals(WITH_CAMEL_CASE10), is(true));
+        String camelCase11 = getCamelCase(WITHOUT_CAMEL_CASE11, conflictResolver);
+        assertThat(camelCase11.equals(WITH_CAMEL_CASE11), is(true));
+        String camelCase12 = getCamelCase(WITHOUT_CAMEL_CASE12, conflictResolver);
+        assertThat(camelCase12.equals(WITH_CAMEL_CASE12), is(true));
+        String camelCase13 = getCamelCase(WITHOUT_CAMEL_CASE13, conflictResolver);
+        assertThat(camelCase13.equals(WITH_CAMEL_CASE13), is(true));
+        String camelCase14 = getCamelCase(WITHOUT_CAMEL_CASE14, conflictResolver);
+        assertThat(camelCase14.equals(WITH_CAMEL_CASE14), is(true));
+    }
+
+    /**
+     * Unit test for getting the camel case along with the prefix provided.
+     */
+    @Test
+    public void getCamelCaseWithPrefixTest() {
+
+        conflictResolver.setPrefixForIdentifier(VALID_PREFIX);
+        String camelCase = getCamelCase(WITHOUT_CAMEL_CASE2, conflictResolver);
+        assertThat(camelCase.equals(WITH_CAMEL_CASE_WITH_PREFIX), is(true));
+        conflictResolver.setPrefixForIdentifier(INVALID_PREFIX1);
+        String camelCase2 = getCamelCase(WITHOUT_CAMEL_CASE3, conflictResolver);
+        assertThat(camelCase2.equals(WITH_CAMEL_CASE_WITH_PREFIX1), is(true));
+    }
+
+    /**
+     * Unit test for getting the camel case along with the invalid prefix provided.
+     */
+    @Test
+    public void getCamelCaseWithInvalidPrefixTest() throws TranslatorException {
+
+        thrown.expect(TranslatorException.class);
+        thrown.expectMessage("The given prefix in pom.xml is invalid.");
+        conflictResolver.setPrefixForIdentifier(INVALID_PREFIX);
+        String camelCase = getCamelCase(WITHOUT_CAMEL_CASE3, conflictResolver);
+    }
+
+    /**
+     * Unit test for getting the camel case for the received string.
+     */
+    @Test
+    public void getSmallCaseTest() {
+        String smallCase = getSmallCase(WITHOUT_CAPITAL);
+        assertThat(smallCase.equals(WITH_SMALL), is(true));
+    }
+
+    /**
+     * Unit test for getting the camel case for the received string.
+     */
+    @Test
+    public void getPackageFromPathTest() {
+        String pkg = getJavaPackageFromPackagePath(PARENT_PACKAGE);
+        assertThat(pkg.equals(PARENT_WITH_PERIOD), is(true));
+    }
+
+    /**
+     * Unit test for getting the camel case for the received string.
+     */
+    @Test
+    public void getPathFromPackageTest() {
+        String path = getPackageDirPathFromJavaJPackage(PARENT_WITH_PERIOD);
+        assertThat(path.equals(PARENT_PACKAGE), is(true));
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGeneratorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGeneratorTest.java
new file mode 100644
index 0000000..05fe52d
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/MethodsGeneratorTest.java
@@ -0,0 +1,318 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.translator.tojava.JavaAttributeInfo;
+import org.onosproject.yangutils.translator.tojava.JavaQualifiedTypeInfo;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.datamodel.YangDataTypes.STRING;
+import static org.onosproject.yangutils.translator.tojava.GeneratedJavaFileType.GENERATE_SERVICE_AND_MANAGER;
+import static org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax.getCapitalCase;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getBuild;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getBuildForInterface;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getCheckNotNull;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getConstructor;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getConstructorStart;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getEqualsMethod;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getGetterForClass;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getGetterForInterface;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getOfMethod;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getOverRideString;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getSetterForClass;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getSetterForInterface;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getSetterForTypeDefClass;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getToStringMethod;
+import static org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator.getTypeConstructorStringAndJavaDoc;
+import static org.onosproject.yangutils.utils.UtilConstants.ADD_STRING;
+import static org.onosproject.yangutils.utils.UtilConstants.BUILD;
+import static org.onosproject.yangutils.utils.UtilConstants.BUILDER;
+import static org.onosproject.yangutils.utils.UtilConstants.CHECK_NOT_NULL_STRING;
+import static org.onosproject.yangutils.utils.UtilConstants.CLOSE_CURLY_BRACKET;
+import static org.onosproject.yangutils.utils.UtilConstants.CLOSE_PARENTHESIS;
+import static org.onosproject.yangutils.utils.UtilConstants.COMMA;
+import static org.onosproject.yangutils.utils.UtilConstants.EIGHT_SPACE_INDENTATION;
+import static org.onosproject.yangutils.utils.UtilConstants.EQUAL;
+import static org.onosproject.yangutils.utils.UtilConstants.EQUALS_STRING;
+import static org.onosproject.yangutils.utils.UtilConstants.FOUR_SPACE_INDENTATION;
+import static org.onosproject.yangutils.utils.UtilConstants.GET_METHOD_PREFIX;
+import static org.onosproject.yangutils.utils.UtilConstants.IMPL;
+import static org.onosproject.yangutils.utils.UtilConstants.JAVA_LANG;
+import static org.onosproject.yangutils.utils.UtilConstants.NEW;
+import static org.onosproject.yangutils.utils.UtilConstants.NEW_LINE;
+import static org.onosproject.yangutils.utils.UtilConstants.OBJECT;
+import static org.onosproject.yangutils.utils.UtilConstants.OBJECT_STRING;
+import static org.onosproject.yangutils.utils.UtilConstants.OF;
+import static org.onosproject.yangutils.utils.UtilConstants.OPEN_CURLY_BRACKET;
+import static org.onosproject.yangutils.utils.UtilConstants.OPEN_PARENTHESIS;
+import static org.onosproject.yangutils.utils.UtilConstants.OVERRIDE;
+import static org.onosproject.yangutils.utils.UtilConstants.PERIOD;
+import static org.onosproject.yangutils.utils.UtilConstants.PUBLIC;
+import static org.onosproject.yangutils.utils.UtilConstants.QUOTES;
+import static org.onosproject.yangutils.utils.UtilConstants.RETURN;
+import static org.onosproject.yangutils.utils.UtilConstants.SEMI_COLAN;
+import static org.onosproject.yangutils.utils.UtilConstants.SET_METHOD_PREFIX;
+import static org.onosproject.yangutils.utils.UtilConstants.SIXTEEN_SPACE_INDENTATION;
+import static org.onosproject.yangutils.utils.UtilConstants.SPACE;
+import static org.onosproject.yangutils.utils.UtilConstants.STATIC;
+import static org.onosproject.yangutils.utils.UtilConstants.STRING_DATA_TYPE;
+import static org.onosproject.yangutils.utils.UtilConstants.SUFFIX_S;
+import static org.onosproject.yangutils.utils.UtilConstants.THIS;
+import static org.onosproject.yangutils.utils.UtilConstants.TWELVE_SPACE_INDENTATION;
+import static org.onosproject.yangutils.utils.UtilConstants.VALUE;
+import static org.onosproject.yangutils.utils.UtilConstants.VOID;
+
+/**
+ * Unit tests for generated methods from the file type.
+ */
+public final class MethodsGeneratorTest {
+
+    private static final String CLASS_NAME = "testname";
+    private static final String ATTRIBUTE_NAME = "testname";
+
+    /**
+     * Unit test for private constructor.
+     *
+     * @throws SecurityException         if any security violation is observed
+     * @throws NoSuchMethodException     if when the method is not found
+     * @throws IllegalArgumentException  if there is illegal argument found
+     * @throws InstantiationException    if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException    if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {MethodsGenerator.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * Unit test case for checking the parse builder and type constructor.
+     */
+    @Test
+    public void getTypeConstructorTest() {
+
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String test = getTypeConstructorStringAndJavaDoc(testAttr, CLASS_NAME, pluginConfig);
+        assertThat(true, is(test.contains(PUBLIC + SPACE + CLASS_NAME + OPEN_PARENTHESIS)));
+    }
+
+    /**
+     * Test for build method for class.
+     */
+    @Test
+    public void getBuildTest() {
+        String method = getBuild(CLASS_NAME);
+        assertThat(true, is(method.equals(FOUR_SPACE_INDENTATION + PUBLIC + SPACE + CLASS_NAME + SPACE + BUILD
+                + OPEN_PARENTHESIS + CLOSE_PARENTHESIS + SPACE + OPEN_CURLY_BRACKET + NEW_LINE + EIGHT_SPACE_INDENTATION
+                + RETURN + SPACE + NEW + SPACE + CLASS_NAME + IMPL + OPEN_PARENTHESIS + THIS + CLOSE_PARENTHESIS
+                + SEMI_COLAN + NEW_LINE + FOUR_SPACE_INDENTATION + CLOSE_CURLY_BRACKET)));
+
+    }
+
+    /**
+     * Test for build method of interface.
+     */
+    @Test
+    public void getBuildForInterfaceTest() {
+        String method = getBuildForInterface(CLASS_NAME);
+        assertThat(true, is(method.equals(FOUR_SPACE_INDENTATION + CLASS_NAME + SPACE + BUILD +
+                OPEN_PARENTHESIS + CLOSE_PARENTHESIS + SEMI_COLAN + NEW_LINE)));
+    }
+
+    /**
+     * Test for check not null method.
+     */
+    @Test
+    public void getCheckNotNullTest() {
+        String method = getCheckNotNull(CLASS_NAME);
+        assertThat(true, is(method.equals(EIGHT_SPACE_INDENTATION + CHECK_NOT_NULL_STRING + OPEN_PARENTHESIS
+                + CLASS_NAME + COMMA + SPACE + CLASS_NAME + CLOSE_PARENTHESIS + SEMI_COLAN + NEW_LINE)));
+    }
+
+    /**
+     * Test case for constructor.
+     */
+    @Test
+    public void getConstructorTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        String method = getConstructor(CLASS_NAME, testAttr, GENERATE_SERVICE_AND_MANAGER, pluginConfig);
+        assertThat(true, is(method.contains(THIS + PERIOD + CLASS_NAME + SPACE + EQUAL + SPACE + "builder" + OBJECT
+                + PERIOD + GET_METHOD_PREFIX + "Testname" + OPEN_PARENTHESIS + CLOSE_PARENTHESIS + SEMI_COLAN)));
+    }
+
+    /**
+     * Test for constrcutor start method.
+     */
+    @Test
+    public void getConstructorStartTest() {
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        String method = getConstructorStart(CLASS_NAME, pluginConfig);
+        assertThat(true, is(method.contains(PUBLIC + SPACE + CLASS_NAME + IMPL + OPEN_PARENTHESIS + CLASS_NAME
+                + BUILDER + SPACE + BUILDER.toLowerCase() + OBJECT + CLOSE_PARENTHESIS + SPACE
+                + OPEN_CURLY_BRACKET + NEW_LINE)));
+    }
+
+    /**
+     * Test case for equals method.
+     */
+    @Test
+    public void getEqualsMethodTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getEqualsMethod(testAttr);
+        assertThat(true, is(method.contains(SIXTEEN_SPACE_INDENTATION + SPACE + OBJECT_STRING + SUFFIX_S + PERIOD
+                + EQUALS_STRING + OPEN_PARENTHESIS)));
+    }
+
+    /**
+     * Test for to string method.
+     */
+    @Test
+    public void getToStringMethodTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getToStringMethod(testAttr);
+        assertThat(true, is(method.equals(
+                TWELVE_SPACE_INDENTATION + PERIOD + ADD_STRING + OPEN_PARENTHESIS + QUOTES + testAttr.getAttributeName()
+                        + QUOTES + COMMA + SPACE + testAttr.getAttributeName() + CLOSE_PARENTHESIS)));
+    }
+
+    /**
+     * Test for getter method of class.
+     */
+    @Test
+    public void getGetterForClassTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getGetterForClass(testAttr, GENERATE_SERVICE_AND_MANAGER);
+        assertThat(true, is(method.contains(PUBLIC + SPACE + STRING_DATA_TYPE + SPACE + GET_METHOD_PREFIX)));
+    }
+
+    /**
+     * Test for getter of interface.
+     */
+    @Test
+    public void getGetterForInterfaceTest() {
+        String method = getGetterForInterface(CLASS_NAME, STRING_DATA_TYPE, false, GENERATE_SERVICE_AND_MANAGER);
+        assertThat(true, is(method.contains(STRING_DATA_TYPE + SPACE + GET_METHOD_PREFIX)));
+    }
+
+    /**
+     * Test case for setter method of class.
+     */
+    @Test
+    public void getSetterForClassTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getSetterForClass(testAttr, CLASS_NAME, GENERATE_SERVICE_AND_MANAGER);
+        assertThat(true, is(
+                method.contains(PUBLIC + SPACE + VOID + SPACE +
+                        SET_METHOD_PREFIX + getCapitalCase(CLASS_NAME) + OPEN_PARENTHESIS +
+                        STRING_DATA_TYPE + SPACE + ATTRIBUTE_NAME)));
+    }
+
+    /**
+     * Test for setter method of interface.
+     */
+    @Test
+    public void getSetterForInterfaceTest() {
+        String method = getSetterForInterface(CLASS_NAME, STRING_DATA_TYPE, CLASS_NAME, false,
+                GENERATE_SERVICE_AND_MANAGER);
+        assertThat(true, is(method.contains(VOID + SPACE +
+                SET_METHOD_PREFIX + "Testname")));
+    }
+
+    /**
+     * Test case for of method.
+     */
+    @Test
+    public void getOfMethodest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getOfMethod(CLASS_NAME, testAttr);
+        assertThat(true, is(method.contains(PUBLIC + SPACE + STATIC + SPACE + CLASS_NAME + SPACE + OF + OPEN_PARENTHESIS
+                + STRING_DATA_TYPE + SPACE + VALUE + CLOSE_PARENTHESIS)));
+    }
+
+    /**
+     * Test case for setter in type def class.
+     */
+    @Test
+    public void getSetterForTypeDefClassTest() {
+        JavaAttributeInfo testAttr = getTestAttribute();
+        String method = getSetterForTypeDefClass(testAttr);
+        assertThat(true, is(method.contains(PUBLIC + SPACE + VOID + SPACE + SET_METHOD_PREFIX)));
+    }
+
+    /**
+     * Test case for over ride string.
+     */
+    @Test
+    public void getOverRideStringTest() {
+        String method = getOverRideString();
+        assertThat(true, is(method.contains(OVERRIDE)));
+    }
+
+    /**
+     * Returns java attribute.
+     *
+     * @return java attribute
+     */
+    private JavaAttributeInfo getTestAttribute() {
+        JavaAttributeInfo testAttr = new JavaAttributeInfo(getTestYangType(), ATTRIBUTE_NAME, false, false);
+        testAttr.setAttributeName(ATTRIBUTE_NAME);
+        testAttr.setAttributeType(getTestYangType());
+        testAttr.setImportInfo(getTestJavaQualifiedTypeInfo());
+        return testAttr;
+    }
+
+    /**
+     * Returns java qualified info.
+     *
+     * @return java qualified info
+     */
+    private JavaQualifiedTypeInfo getTestJavaQualifiedTypeInfo() {
+        JavaQualifiedTypeInfo info = new JavaQualifiedTypeInfo();
+        info.setPkgInfo(JAVA_LANG);
+        info.setClassInfo(STRING_DATA_TYPE);
+        return info;
+    }
+
+    /**
+     * Returns stub YANG type.
+     *
+     * @return test YANG type
+     */
+    private YangType<?> getTestYangType() {
+        YangType<?> attrType = new YangType<>();
+        attrType.setDataTypeName(STRING_DATA_TYPE);
+        attrType.setDataType(STRING);
+        return attrType;
+    }
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/NotificationTranslatorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/NotificationTranslatorTest.java
new file mode 100644
index 0000000..f4d8bf8
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/NotificationTranslatorTest.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Unit tests for union translator.
+ */
+public final class NotificationTranslatorTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks union translation should not result in any exception.
+     */
+    @Test
+    public void processUnionTranslator()
+            throws IOException, ParserException {
+
+        String userDir = System.getProperty("user.dir");
+        YangNode node = manager.getDataModel("src/test/resources/NotificationTest.yang");
+
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir(userDir + "/target/NotificationTest/");
+
+        generateJavaCode(node, yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/NotificationTest/");
+    }
+
+    // TODO enhance the test cases, after having a framework of translator test.
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/RpcTranslatorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/RpcTranslatorTest.java
new file mode 100644
index 0000000..9b8077c
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/RpcTranslatorTest.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Unit tests for rpc translator.
+ */
+public final class RpcTranslatorTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks rpc translation should not result in any exception.
+     */
+    @Test
+    public void processRpcTranslator()
+            throws IOException, ParserException {
+
+        String userDir = System.getProperty("user.dir");
+        YangNode node = manager.getDataModel("src/test/resources/RpcTranslator.yang");
+
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir(userDir + "/target/RpcTestGenFile/");
+
+        generateJavaCode(node, yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/RpcTestGenFile/");
+    }
+    // TODO enhance the test cases, after having a framework of translator test.
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/UnionTranslatorTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/UnionTranslatorTest.java
new file mode 100644
index 0000000..9dcdfdf
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/translator/tojava/utils/UnionTranslatorTest.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.translator.tojava.utils;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import static org.onosproject.yangutils.translator.tojava.JavaCodeGeneratorUtil.generateJavaCode;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+
+/**
+ * Unit tests for union translator.
+ */
+public final class UnionTranslatorTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks union translation should not result in any exception.
+     */
+    @Test
+    public void processUnionTranslator()
+            throws IOException, ParserException {
+
+        String userDir = System.getProperty("user.dir");
+        YangNode node = manager.getDataModel("src/test/resources/UnionTranslator.yang");
+
+        YangPluginConfig yangPluginConfig = new YangPluginConfig();
+        yangPluginConfig.setCodeGenDir("target/UnionTestGenFile/");
+
+        generateJavaCode(node, yangPluginConfig);
+
+        deleteDirectory(userDir + "/target/UnionTestGenFile/");
+    }
+
+    // TODO enhance the test cases, after having a framework of translator test.
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java
new file mode 100644
index 0000000..a63d432
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/UtilConstantsTest.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test case for testing the util constants.
+ */
+public final class UtilConstantsTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {UtilConstants.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/CopyrightHeaderTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/CopyrightHeaderTest.java
new file mode 100644
index 0000000..40ac92c
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/CopyrightHeaderTest.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.io.impl;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Calendar;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static org.apache.commons.io.FileUtils.contentEquals;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.utils.io.impl.CopyrightHeader.getCopyrightHeader;
+
+/**
+ * Unit Tests for the CopyrightHeader contents.
+ */
+public final class CopyrightHeaderTest {
+
+    private static final String COPYRIGHTS_FIRST_LINE = "/*\n * Copyright " + Calendar.getInstance().get(Calendar.YEAR)
+            + "-present Open Networking Laboratory\n";
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * Unit test for testing private constructor.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {CopyrightHeader.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * This test case checks the received copyright header contents.
+     *
+     * @throws IOException when fails to do IO operations
+     */
+    @Test
+    public void testGetCopyrightHeader() throws IOException {
+
+        String path = "src/test/resources/CopyrightHeader.txt";
+
+        File testRsc = new File(path);
+        FileInputStream in = new FileInputStream(testRsc);
+
+        File testFile = new File("target/TestHeader.txt");
+        FileOutputStream out = new FileOutputStream(testFile);
+
+        out.write(COPYRIGHTS_FIRST_LINE.getBytes());
+        int c = 0;
+        while ((c = in.read()) != -1) {
+            out.write(c);
+        }
+
+        String licenseHeader = getCopyrightHeader();
+        File test = new File("target/TestCopyrightHeader.txt");
+
+        FileWriter writer = new FileWriter(test);
+        writer.write(licenseHeader);
+        writer.close();
+        out.close();
+        out.flush();
+        in.close();
+
+        assertThat(true, is(contentEquals(test, testFile)));
+        test.delete();
+        testFile.delete();
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtilTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtilTest.java
new file mode 100644
index 0000000..5fd728b
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/FileSystemUtilTest.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.io.impl;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.translator.tojava.JavaFileInfo;
+import org.onosproject.yangutils.translator.tojava.javamodel.YangJavaModule;
+import org.onosproject.yangutils.translator.tojava.utils.YangPluginConfig;
+
+import static org.apache.commons.io.FileUtils.deleteDirectory;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.utils.UtilConstants.PERIOD;
+import static org.onosproject.yangutils.utils.UtilConstants.SLASH;
+import static org.onosproject.yangutils.utils.io.impl.FileSystemUtil.appendFileContents;
+import static org.onosproject.yangutils.utils.io.impl.FileSystemUtil.createPackage;
+import static org.onosproject.yangutils.utils.io.impl.FileSystemUtil.doesPackageExist;
+import static org.onosproject.yangutils.utils.io.impl.FileSystemUtil.updateFileHandle;
+
+/**
+ * Tests the file handle utilities.
+ */
+public final class FileSystemUtilTest {
+
+    private static final String BASE_DIR_PKG = "target.UnitTestCase.";
+    private static final String BASE_PKG = "target/UnitTestCase";
+    private static final String TEST_DATA_1 = "This is to append a text to the file first1\n";
+    private static final String TEST_DATA_2 = "This is next second line\n";
+    private static final String TEST_DATA_3 = "This is next third line in the file";
+    private static final String TEST_FILE = "testFile";
+    private static final String SOURCE_TEST_FILE = "sourceTestFile";
+    private static final String DIR_PATH = "exist1.exist2.exist3";
+    private static final String PKG_INFO = "package-info.java";
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {FileSystemUtil.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * This test case checks the contents to be written in the file.
+     *
+     * @throws IOException when fails to create a test file
+     */
+    @Test
+    public void updateFileHandleTest() throws IOException {
+
+        File dir = new File(BASE_PKG + SLASH + TEST_FILE);
+        dir.mkdirs();
+        File createFile = new File(dir + TEST_FILE);
+        createFile.createNewFile();
+        File createSourceFile = new File(dir + SOURCE_TEST_FILE);
+        createSourceFile.createNewFile();
+        updateFileHandle(createFile, TEST_DATA_1, false);
+        updateFileHandle(createFile, TEST_DATA_2, false);
+        updateFileHandle(createFile, TEST_DATA_3, false);
+        appendFileContents(createFile, createSourceFile);
+        updateFileHandle(createFile, null, true);
+        deleteDirectory(dir);
+    }
+
+    /**
+     * This test  case checks whether the package is existing.
+     *
+     * @throws IOException when failed to create a test file
+     */
+    @Test
+    public void packageExistTest() throws IOException {
+
+        String strPath = BASE_DIR_PKG + DIR_PATH;
+        File createDir = new File(strPath.replace(PERIOD, SLASH));
+        createDir.mkdirs();
+        File createFile = new File(createDir + SLASH + PKG_INFO);
+        createFile.createNewFile();
+        assertThat(true, is(doesPackageExist(strPath)));
+        createPackage(getStubNode());
+        createDir.delete();
+        deleteDirectory(createDir);
+    }
+
+    /**
+     * Returns stub YANG node.
+     *
+     * @return stub node
+     */
+    private YangNode getStubNode() {
+        YangJavaModule module = new YangJavaModule();
+        module.setName(TEST_DATA_1);
+        JavaFileInfo javafileInfo = new JavaFileInfo();
+        javafileInfo.setJavaName(TEST_DATA_1);
+        javafileInfo.setBaseCodeGenPath("");
+        javafileInfo.setPackageFilePath(BASE_PKG);
+        javafileInfo.setPluginConfig(getStubPluginConfig());
+        module.setJavaFileInfo(javafileInfo);
+        return module;
+    }
+
+    /**
+     * Returns stub pluginConfig.
+     *
+     * @return stub pluginConfig
+     */
+    private YangPluginConfig getStubPluginConfig() {
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        pluginConfig.setConflictResolver(null);
+        return pluginConfig;
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/JavaDocGenTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/JavaDocGenTest.java
new file mode 100644
index 0000000..2e9f436
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/JavaDocGenTest.java
@@ -0,0 +1,210 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.io.impl;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.translator.tojava.utils.YangPluginConfig;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.getJavaDoc;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.BUILDER_CLASS;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.BUILDER_INTERFACE;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.BUILD_METHOD;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.CONSTRUCTOR;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.DEFAULT_CONSTRUCTOR;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.GETTER_METHOD;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.IMPL_CLASS;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.INTERFACE;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.PACKAGE_INFO;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.SETTER_METHOD;
+import static org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType.TYPE_DEF_SETTER_METHOD;
+
+/**
+ * Tests the java doc that is generated.
+ */
+public final class JavaDocGenTest {
+
+    private static final String TEST_NAME = "testName";
+    private static final String END_STRING = " */\n";
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * This test case checks the content received for the builder class java doc.
+     */
+    @Test
+    public void builderClassGenerationTest() {
+        String builderClassJavaDoc = getJavaDoc(BUILDER_CLASS, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true, is(builderClassJavaDoc.contains("Represents the builder implementation of")
+                && builderClassJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the builder interface ge java doc.
+     */
+    @Test
+    public void builderInterfaceGenerationTest() {
+        String builderInterfaceJavaDoc = getJavaDoc(BUILDER_INTERFACE, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(builderInterfaceJavaDoc.contains("Builder for")
+                        && builderInterfaceJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the build  java doc.
+     */
+    @Test
+    public void buildGenerationTest() {
+        String buildDoc = getJavaDoc(BUILD_METHOD, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true, is(buildDoc.contains("Builds object of") && buildDoc.contains(END_STRING)));
+    }
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {JavaDocGen.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * This test case checks the content received for the constructor java doc.
+     */
+    @Test
+    public void constructorGenerationTest() {
+        String constructorDoc = getJavaDoc(CONSTRUCTOR, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(constructorDoc.contains("Creates an instance of ")
+                        && constructorDoc.contains("builder object of")
+                        && constructorDoc.contains("@param") && constructorDoc.contains("*/\n")));
+    }
+
+    /**
+     * This test case checks the content received for the default constructor java doc.
+     */
+    @Test
+    public void defaultConstructorGenerationTest() {
+        String defaultConstructorDoc = getJavaDoc(DEFAULT_CONSTRUCTOR, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true, is(defaultConstructorDoc.contains("Creates an instance of ")
+                && defaultConstructorDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the getter java doc.
+     */
+    @Test
+    public void getterGenerationTest() {
+        String getterJavaDoc = getJavaDoc(GETTER_METHOD, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(getterJavaDoc.contains("Returns the attribute") && getterJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the impl class java doc.
+     */
+    @Test
+    public void implClassGenerationTest() {
+        String implClassJavaDoc = getJavaDoc(IMPL_CLASS, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(implClassJavaDoc.contains("Represents the implementation of")
+                        && implClassJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the interface java doc.
+     */
+    @Test
+    public void interfaceGenerationTest() {
+        String interfaceJavaDoc = getJavaDoc(INTERFACE, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(interfaceJavaDoc.contains("Abstraction of an entity which represents the functionality of")
+                        && interfaceJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the package info  java doc.
+     */
+    @Test
+    public void packageInfoGenerationTest() {
+        String packageInfo = getJavaDoc(PACKAGE_INFO, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(packageInfo.contains("Implementation of YANG node") && packageInfo.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the package info  java doc.
+     */
+    @Test
+    public void packageInfoGenerationForChildNodeTest() {
+        String packageInfo = getJavaDoc(PACKAGE_INFO, TEST_NAME, true, getStubPluginConfig());
+        assertThat(true, is(packageInfo.contains("Implementation of YANG node testName's children nodes")
+                && packageInfo.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the setter java doc.
+     */
+    @Test
+    public void setterGenerationTest() {
+        String setterJavaDoc = getJavaDoc(SETTER_METHOD, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true,
+                is(setterJavaDoc.contains("Returns the builder object of") && setterJavaDoc.contains(END_STRING)));
+    }
+
+    /**
+     * This test case checks the content received for the typedef setter java doc.
+     */
+    @Test
+    public void typeDefSetterGenerationTest() {
+        String typeDefSetter = getJavaDoc(TYPE_DEF_SETTER_METHOD, TEST_NAME, false, getStubPluginConfig());
+        assertThat(true, is(typeDefSetter.contains("Sets the value of") && typeDefSetter.contains(END_STRING)));
+    }
+
+    /**
+     * Returns stub pluginConfig.
+     *
+     * @return stub pluginConfig
+     */
+    private YangPluginConfig getStubPluginConfig() {
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        pluginConfig.setConflictResolver(null);
+        return pluginConfig;
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangFileScannerTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangFileScannerTest.java
new file mode 100644
index 0000000..566d24b
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangFileScannerTest.java
@@ -0,0 +1,166 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.io.impl;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static java.io.File.separator;
+
+import static org.apache.commons.io.FileUtils.deleteDirectory;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.utils.io.impl.YangFileScanner.getJavaFiles;
+import static org.onosproject.yangutils.utils.io.impl.YangFileScanner.getYangFiles;
+
+/**
+ * Test the file scanner service.
+ */
+public final class YangFileScannerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    String baseDir = "target/UnitTestCase";
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException         if any security violation is observed
+     * @throws NoSuchMethodException     if when the method is not found
+     * @throws IllegalArgumentException  if there is illegal argument found
+     * @throws InstantiationException    if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException    if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {YangFileScanner.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * This test case checks for a .java file inside the specified dir.
+     *
+     * @throws IOException when fails to do IO operations
+     */
+    @Test
+    public void checkJavaFileInsideDirTest() throws IOException {
+
+        String dir = baseDir + separator + "scanner2";
+        File path = createDirectory(dir);
+        createFile(path, "testScanner.java");
+        List<String> dirContents = getJavaFiles(path.toString());
+        List<String> expectedContents = new LinkedList<>();
+        expectedContents.add(path.getCanonicalPath() + separator + "testScanner.java");
+        assertThat(true, is(dirContents.equals(expectedContents)));
+        deleteDirectory(path);
+    }
+
+    /**
+     * Method used for creating multiple directories inside the target file.
+     *
+     * @param path where directories should be created
+     * @return the directory path that is created
+     */
+    private File createDirectory(String path) {
+
+        File myDir = new File(path);
+        myDir.mkdirs();
+        return myDir;
+    }
+
+    /**
+     * Method used for creating file inside the specified directory.
+     *
+     * @param myDir    the path where file has to be created inside
+     * @param fileName the name of the file to be created
+     */
+    private void createFile(File myDir, String fileName) throws IOException {
+
+        File file = null;
+        file = new File(myDir + separator + fileName);
+        file.createNewFile();
+    }
+
+    /**
+     * This testcase checks for a java file inside an empty directory.
+     *
+     * @throws IOException when fails to do IO operations
+     */
+    @Test
+    public void emptyDirJavaScannerTest() throws IOException {
+
+        String emptyDir = baseDir + separator + "scanner1";
+        File path = createDirectory(emptyDir);
+        List<String> emptyDirContents = getJavaFiles(path.toString());
+        List<String> expectedContents = new LinkedList<>();
+        assertThat(true, is(emptyDirContents.equals(expectedContents)));
+        deleteDirectory(path);
+    }
+
+    /**
+     * This testcase checks for a yang file inside an empty directory.
+     *
+     * @throws IOException when fails to do IO operations
+     */
+    @Test
+    public void emptyDirYangScannerTest() throws IOException {
+
+        String emptyYangDir = baseDir + separator + "scanner1";
+        File path = createDirectory(emptyYangDir);
+        List<String> emptyDirContents = getYangFiles(path.toString());
+        List<String> expectedContents = new LinkedList<>();
+        assertThat(true, is(emptyDirContents.equals(expectedContents)));
+        deleteDirectory(path);
+    }
+
+    /**
+     * This test case checks with the sub directories in the given path for java files.
+     *
+     * @throws IOException when fails to do IO operations
+     */
+    @Test
+    public void emptySubDirScannerTest() throws IOException {
+
+        String dir = baseDir + separator + "scanner3";
+        File path = createDirectory(dir);
+        String subDir = path.toString() + separator + "subDir1";
+        createDirectory(subDir);
+        createFile(path, "invalidFile.txt");
+        List<String> emptySubDirContents = getJavaFiles(path.toString());
+        List<String> expectedContents = new LinkedList<>();
+        assertThat(true, is(emptySubDirContents.equals(expectedContents)));
+        deleteDirectory(path);
+    }
+
+}
diff --git a/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangIoUtilsTest.java b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangIoUtilsTest.java
new file mode 100644
index 0000000..c10ed03
--- /dev/null
+++ b/utils/yangutils/plugin/src/test/java/org/onosproject/yangutils/utils/io/impl/YangIoUtilsTest.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.utils.io.impl;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.maven.project.MavenProject;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.translator.tojava.utils.YangPluginConfig;
+import org.onosproject.yangutils.utils.UtilConstants;
+import org.sonatype.plexus.build.incremental.BuildContext;
+import org.sonatype.plexus.build.incremental.DefaultBuildContext;
+
+import static org.apache.commons.io.FileUtils.deleteDirectory;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.addPackageInfo;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.addToCompilationRoot;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.deleteDirectory;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.createDirectories;
+import static org.onosproject.yangutils.utils.io.impl.YangIoUtils.trimAtLast;
+
+/**
+ * Unit tests for YANG IO utils.
+ */
+public final class YangIoUtilsTest {
+
+    private static final String BASE_DIR = "target/UnitTestCase";
+    private static final String CREATE_PATH = BASE_DIR + File.separator + "dir1/dir2/dir3/dir4/";
+    private static final String CHECK_STRING = "one, two, three, four, five, six";
+    private static final String TRIM_STRING = "one, two, three, four, five, ";
+    private static final String CHECK1 = "check1";
+    private static final String PKG_INFO = "package-info.java";
+    private static final String PATH = "src/main/yangmodel/";
+    private static final String MSG = "Exception occured while creating package info file.";
+
+    /**
+     * Expected exceptions.
+     */
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    /**
+     * This test case checks whether the package-info file is created.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void addPackageInfoTest() throws IOException {
+
+        File dirPath = new File(CREATE_PATH);
+        dirPath.mkdirs();
+        addPackageInfo(dirPath, CHECK1, CREATE_PATH, false, getStubPluginConfig());
+        File filePath = new File(dirPath + File.separator + PKG_INFO);
+        assertThat(filePath.isFile(), is(true));
+        FileUtils.deleteDirectory(dirPath);
+    }
+
+    /**
+     * This test case checks with an additional info in the path.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void addPackageInfoWithPathTest() throws IOException {
+
+        File dirPath = new File(CREATE_PATH);
+        dirPath.mkdirs();
+        addPackageInfo(dirPath, CHECK1, PATH + CREATE_PATH, false, getStubPluginConfig());
+        File filePath = new File(dirPath + File.separator + PKG_INFO);
+        assertThat(filePath.isFile(), is(true));
+        FileUtils.deleteDirectory(dirPath);
+    }
+
+    /**
+     * This test case checks with a child node.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void addPackageInfoWithChildNode() throws IOException {
+
+        File dirPath = new File(CREATE_PATH);
+        dirPath.mkdirs();
+        addPackageInfo(dirPath, CHECK1, PATH + CREATE_PATH, true, getStubPluginConfig());
+        File filePath = new File(dirPath + File.separator + PKG_INFO);
+        assertThat(filePath.isFile(), is(true));
+        FileUtils.deleteDirectory(dirPath);
+    }
+
+    /**
+     * This test case checks whether the package-info file is created when invalid path is given.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void addPackageInfoWithEmptyPathTest() throws IOException {
+
+        File dirPath = new File("invalid/check");
+        thrown.expect(IOException.class);
+        thrown.expectMessage(MSG);
+        addPackageInfo(dirPath, CHECK1, CREATE_PATH, false, getStubPluginConfig());
+        File filePath1 = new File(dirPath + File.separator + PKG_INFO);
+        assertThat(filePath1.isFile(), is(false));
+        FileUtils.deleteDirectory(dirPath);
+    }
+
+    /**
+     * A private constructor is tested.
+     *
+     * @throws SecurityException if any security violation is observed
+     * @throws NoSuchMethodException if when the method is not found
+     * @throws IllegalArgumentException if there is illegal argument found
+     * @throws InstantiationException if instantiation is provoked for the private constructor
+     * @throws IllegalAccessException if instance is provoked or a method is provoked
+     * @throws InvocationTargetException when an exception occurs by the method or constructor
+     */
+    @Test
+    public void callPrivateConstructors()
+            throws SecurityException, NoSuchMethodException, IllegalArgumentException,
+            InstantiationException, IllegalAccessException, InvocationTargetException {
+
+        Class<?>[] classesToConstruct = {YangIoUtils.class };
+        for (Class<?> clazz : classesToConstruct) {
+            Constructor<?> constructor = clazz.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            assertThat(null, not(constructor.newInstance()));
+        }
+    }
+
+    /**
+     * This test case checks if the directory is cleaned.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void cleanGeneratedDirTest() throws IOException {
+
+        File baseDirPath = new File(BASE_DIR);
+        File createNewDir = new File(BASE_DIR + File.separator + UtilConstants.YANG_GEN_DIR);
+        createNewDir.mkdirs();
+        File createFile = new File(createNewDir + File.separator + "check1.java");
+        createFile.createNewFile();
+        deleteDirectory(baseDirPath.getAbsolutePath());
+        FileUtils.deleteDirectory(createNewDir);
+        FileUtils.deleteDirectory(baseDirPath);
+    }
+
+    /**
+     * This test case checks the cleaning method when an invalid path is provided.
+     *
+     * @throws IOException when fails to do IO operations for test case
+     */
+    @Test
+    public void cleanWithInvalidDirTest() throws IOException {
+
+        File baseDirPath = new File(BASE_DIR + "invalid");
+        deleteDirectory(baseDirPath.getAbsolutePath());
+    }
+
+    /**
+     * This test case tests whether the directories are getting created.
+     */
+    @Test
+    public void createDirectoryTest() throws IOException {
+
+        File dirPath = createDirectories(CREATE_PATH);
+        assertThat(dirPath.isDirectory(), is(true));
+        FileUtils.deleteDirectory(dirPath);
+    }
+
+    /**
+     * This test case checks whether the source is getting added.
+     */
+    @Test
+    public void testForAddSource() throws IOException {
+
+        MavenProject project = new MavenProject();
+        BuildContext context = new DefaultBuildContext();
+        File sourceDir = new File(BASE_DIR + File.separator + "yang");
+        sourceDir.mkdirs();
+        addToCompilationRoot(sourceDir.toString(), project, context);
+        FileUtils.deleteDirectory(sourceDir);
+    }
+
+    /**
+     * Unit test case for trim at last method.
+     */
+    @Test
+    public void testForTrimAtLast() {
+
+        String test = trimAtLast(CHECK_STRING, "six");
+        assertThat(test.contains(TRIM_STRING), is(true));
+    }
+
+    /**
+     * Returns stub pluginConfig.
+     *
+     * @return stub pluginConfig
+     */
+    private YangPluginConfig getStubPluginConfig() {
+        YangPluginConfig pluginConfig = new YangPluginConfig();
+        pluginConfig.setConflictResolver(null);
+        return pluginConfig;
+    }
+}