diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java
new file mode 100644
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--- /dev/null
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnionListenerTest.java
@@ -0,0 +1,141 @@
+/*
+ * 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.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.getLeafName(), 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.getLeafName(), 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");
+    }
+}