Add unit tests for MastershipEvent

- Add hashCode and equals for MastershipEvent

Change-Id: I7897b9efc139db014ebee0b00025b257ca00a4b6
diff --git a/core/api/src/main/java/org/onosproject/mastership/MastershipEvent.java b/core/api/src/main/java/org/onosproject/mastership/MastershipEvent.java
index 1156787..8bc8653 100644
--- a/core/api/src/main/java/org/onosproject/mastership/MastershipEvent.java
+++ b/core/api/src/main/java/org/onosproject/mastership/MastershipEvent.java
@@ -22,6 +22,8 @@
 
 import com.google.common.base.MoreObjects;
 
+import java.util.Objects;
+
 /**
  * Describes a device mastership event.
  */
@@ -90,6 +92,26 @@
     }
 
     @Override
+    public int hashCode() {
+        return Objects.hash(type(), subject(), roleInfo(), time());
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof MastershipEvent) {
+            final MastershipEvent other = (MastershipEvent) obj;
+            return Objects.equals(this.type(), other.type()) &&
+                    Objects.equals(this.subject(), other.subject()) &&
+                    Objects.equals(this.roleInfo(), other.roleInfo()) &&
+                    Objects.equals(this.time(), other.time());
+        }
+        return false;
+    }
+
+    @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
                 .add("time", new LocalDateTime(time()))
diff --git a/core/api/src/test/java/org/onosproject/mastership/MastershipEventTest.java b/core/api/src/test/java/org/onosproject/mastership/MastershipEventTest.java
new file mode 100644
index 0000000..9e2acd2
--- /dev/null
+++ b/core/api/src/test/java/org/onosproject/mastership/MastershipEventTest.java
@@ -0,0 +1,84 @@
+/*
+ * 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.mastership;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import org.onosproject.cluster.NodeId;
+import org.onosproject.cluster.RoleInfo;
+import org.onosproject.net.DeviceId;
+
+import java.util.Arrays;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Unit tests for the mastership event.
+ */
+public class MastershipEventTest {
+    private final long time = System.currentTimeMillis();
+    private final DeviceId deviceId1 = DeviceId.deviceId("foo:bar");
+    private final DeviceId deviceId2 = DeviceId.deviceId("bar:baz");
+    private final NodeId node1 = new NodeId("1");
+    private final NodeId node2 = new NodeId("2");
+    private final RoleInfo roleInfo1 = new RoleInfo(node1, Arrays.asList(node1, node2));
+    private final RoleInfo roleInfo2 = new RoleInfo(node2, Arrays.asList(node2, node1));
+
+    private final MastershipEvent event1 =
+            new MastershipEvent(MastershipEvent.Type.BACKUPS_CHANGED, deviceId1, roleInfo1);
+    private final MastershipEvent event2 =
+            new MastershipEvent(MastershipEvent.Type.MASTER_CHANGED, deviceId1, roleInfo1);
+    private final MastershipEvent event3 =
+            new MastershipEvent(MastershipEvent.Type.SUSPENDED, deviceId1, roleInfo1);
+    private final MastershipEvent event4 =
+            new MastershipEvent(MastershipEvent.Type.MASTER_CHANGED, deviceId1, roleInfo2, time);
+    private final MastershipEvent sameAsEvent4 =
+            new MastershipEvent(MastershipEvent.Type.MASTER_CHANGED, deviceId1, roleInfo2, time);
+    private final MastershipEvent event5 =
+            new MastershipEvent(MastershipEvent.Type.BACKUPS_CHANGED, deviceId2, roleInfo1);
+
+    /**
+     * Tests for proper operation of equals(), hashCode() and toString() methods.
+     */
+    @Test
+    public void checkEquals() {
+        new EqualsTester()
+                .addEqualityGroup(event1)
+                .addEqualityGroup(event2)
+                .addEqualityGroup(event3)
+                .addEqualityGroup(event4, sameAsEvent4)
+                .addEqualityGroup(event5)
+                .testEquals();
+    }
+
+    /**
+     * Tests that objects are created properly.
+     */
+    @Test
+    public void checkConstruction() {
+        assertThat(event1.type(), is(MastershipEvent.Type.BACKUPS_CHANGED));
+        assertThat(event1.subject(), is(deviceId1));
+        assertThat(event1.roleInfo(), is(roleInfo1));
+
+        assertThat(event4.time(), is(time));
+        assertThat(event4.type(), is(MastershipEvent.Type.MASTER_CHANGED));
+        assertThat(event4.subject(), is(deviceId1));
+        assertThat(event4.roleInfo(), is(roleInfo2));
+    }
+
+}