Unit tests for LinkKey and Criteria classes.

Change-Id: I4957cd01c66f191cb679da57779283f50db3911c

+/*
+ * Copyright 2014 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.onlab.onos.net;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.allOf;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.PortNumber.portNumber;
+
+/**
+ * Unit tests for the LinkKey class.
+ */
+public class LinkKeyTest {
+
+    static final DeviceId D1 = deviceId("1");
+    static final DeviceId D2 = deviceId("2");
+    static final PortNumber P1 = portNumber(1);
+    static final PortNumber P2 = portNumber(2);
+
+    static final ConnectPoint SRC1 = new ConnectPoint(D1, P1);
+    static final ConnectPoint DST1 = new ConnectPoint(D2, P1);
+    static final ConnectPoint DST2 = new ConnectPoint(D2, P2);
+
+
+    /**
+     * Checks that the LinkKey class is immutable.
+     */
+    @Test
+    public void testLinkKeyImmutability() {
+        assertThatClassIsImmutable(LinkKey.class);
+    }
+
+    /**
+     * Check null source connection.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testNullSrc() {
+        LinkKey key = LinkKey.linkKey(null, DST1);
+    }
+
+    /**
+     * Check null destination connection.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testNullDst() {
+        LinkKey key = LinkKey.linkKey(SRC1, null);
+    }
+
+    /**
+     * Check that two LinkKeys based on the same source/destination pair compare
+     * equal.
+     */
+    @Test
+    public void testCompareEquals() {
+        LinkKey k1 = LinkKey.linkKey(SRC1, DST2);
+        LinkKey k2 = LinkKey.linkKey(SRC1, DST2);
+
+        assertThat(k1, is(equalTo(k2)));
+    }
+
+    /**
+     * Check that two LinkKeys based on different source/destination pairs compare
+     * not equal.
+     */
+    @Test
+    public void testCompareNotEquals() {
+        LinkKey k1 = LinkKey.linkKey(SRC1, DST1);
+        LinkKey k2 = LinkKey.linkKey(SRC1, DST2);
+
+        assertThat(k1, is(not(equalTo(k2))));
+        assertThat(k1, is(not(equalTo(new Object()))));
+    }
+
+    /**
+     * Check that two LinkKeys based on the same source/destination pair compare
+     * equal.
+     */
+    @Test
+    public void testHashCodeEquals() {
+        LinkKey k1 = LinkKey.linkKey(SRC1, DST2);
+        LinkKey k2 = LinkKey.linkKey(SRC1, DST2);
+
+        assertThat(k1.hashCode(), is(equalTo(k2.hashCode())));
+    }
+
+    /**
+     * Check that two LinkKeys based on different source/destination pairs compare
+     * not equal.
+     */
+    @Test
+    public void testHashCodeNotEquals() {
+        LinkKey k1 = LinkKey.linkKey(SRC1, DST1);
+        LinkKey k2 = LinkKey.linkKey(SRC1, DST2);
+
+        assertThat(k1.hashCode(), is(not(equalTo(k2.hashCode()))));
+    }
+
+    /**
+     * Check the toString() method of LinkKey.
+     */
+    @Test
+    public void testToString() {
+        LinkKey k1 = LinkKey.linkKey(SRC1, DST1);
+        String k1String = k1.toString();
+        assertThat(k1String, allOf(containsString("LinkKey{"),
+                                   containsString("src=ConnectPoint{elementId=1, portNumber=1}"),
+                                   containsString("dst=ConnectPoint{elementId=2, portNumber=1}")));
+    }
+}