[ONOS-3252] Add the junit test code of VirtualPortId

Change-Id: Ia26594913a7c33406379a0015464c89567790a42

+/*
+ * Copyright 2015 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.vtnrsc.virtualport;
+
+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;
+
+import org.junit.Test;
+import org.onosproject.vtnrsc.VirtualPortId;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Unit tests for VirtualPortId class.
+ */
+public class VirtualPortIdTest {
+
+    final VirtualPortId virtualPortId1 = VirtualPortId.portId("1");
+    final VirtualPortId sameAsVirtualPortId1 = VirtualPortId.portId("1");
+    final VirtualPortId virtualPortId2 = VirtualPortId.portId("2");
+
+    /**
+     * Checks that the VirtualPortId class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(VirtualPortId.class);
+    }
+
+    /**
+     * Checks the operation of equals().
+     */
+    @Test
+    public void testEquals() {
+        new EqualsTester().addEqualityGroup(virtualPortId1, sameAsVirtualPortId1)
+                .addEqualityGroup(virtualPortId2).testEquals();
+    }
+
+    /**
+     * Checks the construction of a VirtualPortId object.
+     */
+    @Test
+    public void testConstruction() {
+        final String vPortIdValue = "aaa";
+        final VirtualPortId virtualPortId = VirtualPortId.portId(vPortIdValue);
+        assertThat(virtualPortId, is(notNullValue()));
+        assertThat(virtualPortId.portId(), is(vPortIdValue));
+
+    }
+}