Add unit tests for mapping management app

Change-Id: Ie8be52be8c65ba39e8acf541af991865248b019b
diff --git a/apps/mappingmanagement/api/src/test/java/org/onosproject/mapping/MappingIdTest.java b/apps/mappingmanagement/api/src/test/java/org/onosproject/mapping/MappingIdTest.java
new file mode 100644
index 0000000..0acdcaa
--- /dev/null
+++ b/apps/mappingmanagement/api/src/test/java/org/onosproject/mapping/MappingIdTest.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017-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.mapping;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+/**
+ * Unit tests for mapping id class.
+ */
+public class MappingIdTest {
+
+    final MappingId mappingId1 = MappingId.valueOf(1);
+    final MappingId sameAsMappingId1 = MappingId.valueOf(1);
+    final MappingId mappingId2 = MappingId.valueOf(2);
+
+    /**
+     * Checks that the MappingId class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(MappingId.class);
+    }
+
+    /**
+     * Checks the operation of equals(), hashCode() and toString() methods.
+     */
+    @Test
+    public void testEquals() {
+        new EqualsTester()
+                .addEqualityGroup(mappingId1, sameAsMappingId1)
+                .addEqualityGroup(mappingId2)
+                .testEquals();
+    }
+
+    /**
+     * Checks the construction of a MappingId object.
+     */
+    @Test
+    public void testConstruction() {
+        final long mappingIdValue = 8888L;
+        final MappingId mappingId = MappingId.valueOf(mappingIdValue);
+        assertThat(mappingId, is(notNullValue()));
+        assertThat(mappingId.value(), is(mappingIdValue));
+    }
+}