Renamed AbstractListenerRegistry to ListenerRegistry (since it is not abstract).
- added checkForNonRegistrant() predicate and augmented unit tests.

Change-Id: I7ecc618f01fdc4cead6f143a1e5e0ddd03268efc
diff --git a/core/api/src/test/java/org/onosproject/event/ListenerRegistryTest.java b/core/api/src/test/java/org/onosproject/event/ListenerRegistryTest.java
new file mode 100644
index 0000000..5645926
--- /dev/null
+++ b/core/api/src/test/java/org/onosproject/event/ListenerRegistryTest.java
@@ -0,0 +1,93 @@
+/*
+ * 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.onosproject.event;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Unit tests for {@link ListenerRegistry}.
+ */
+public class ListenerRegistryTest {
+
+    private static class RelaxedRegistry extends TestListenerRegistry {
+        @Override
+        protected boolean checkForNonRegistrant() {
+            return false;
+        }
+    }
+
+    private static final TestEvent FOO_EVENT =
+            new TestEvent(TestEvent.Type.FOO, "foo");
+    private static final TestEvent BAR_EVENT =
+            new TestEvent(TestEvent.Type.BAR, "bar");
+
+    private TestListener listener;
+    private TestListener secondListener;
+    private TestListenerRegistry manager;
+
+    @Before
+    public void setUp() {
+        listener = new TestListener();
+        secondListener = new TestListener();
+        manager = new TestListenerRegistry();
+    }
+
+    @Test
+    public void basics() {
+        manager.addListener(listener);
+        manager.addListener(secondListener);
+
+        manager.process(BAR_EVENT);
+        assertTrue("BAR not processed", listener.events.contains(BAR_EVENT));
+        assertTrue("BAR not processed", secondListener.events.contains(BAR_EVENT));
+
+        manager.removeListener(listener);
+
+        manager.process(FOO_EVENT);
+        assertFalse("FOO processed", listener.events.contains(FOO_EVENT));
+        assertTrue("FOO not processed", secondListener.events.contains(FOO_EVENT));
+    }
+
+    @Test
+    public void badListener() {
+        listener = new BrokenListener();
+
+        manager.addListener(listener);
+        manager.addListener(secondListener);
+
+        manager.process(BAR_EVENT);
+        assertFalse("BAR processed", listener.events.contains(BAR_EVENT));
+        assertFalse("error not reported", manager.errors.isEmpty());
+        assertTrue("BAR not processed", secondListener.events.contains(BAR_EVENT));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void removeNonListenerCausesException() {
+        manager.removeListener(listener);
+    }
+
+    @Test
+    public void removeNonListenerIgnored() {
+        manager = new RelaxedRegistry();
+        manager.removeListener(listener);
+        assertTrue("what?", manager.listeners.isEmpty());
+    }
+
+}