Implement equals/hashCode methods for CopyOnWriteList class, cover logic with unit test

Signed-off-by: Winston Prakash <winston.prakash@gmail.com>

2 files changed, 94 insertions, 3 deletions

diff --git a/hudson-core/src/main/java/hudson/util/CopyOnWriteList.java b/hudson-core/src/main/java/hudson/util/CopyOnWriteList.java
index cd68365..84b6660 100644
--- a/hudson-core/src/main/java/hudson/util/CopyOnWriteList.java
+++ b/hudson-core/src/main/java/hudson/util/CopyOnWriteList.java
@@ -1,6 +1,6 @@
 /*******************************************************************************
  *
- * Copyright (c) 2004-2009 Oracle Corporation.
+ * Copyright (c) 2004-2011 Oracle Corporation.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -9,7 +9,7 @@
  *
  * Contributors: 
 *
-*    Kohsuke Kawaguchi
+*    Kohsuke Kawaguchi, Nikita Levyankov
  *     
  *
  *******************************************************************************/ 
@@ -31,8 +31,8 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Arrays;
-import java.util.logging.Level;
 import java.util.logging.Logger;
+import org.apache.commons.collections.CollectionUtils;
 
 import static java.util.logging.Level.WARNING;
 
@@ -196,5 +196,23 @@ public class CopyOnWriteList<E> implements Iterable<E> {
         }
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        CopyOnWriteList that = (CopyOnWriteList) o;
+        return CollectionUtils.isEqualCollection(this.core, that.core);
+    }
+
+    @Override
+    public int hashCode() {
+        return core != null ? core.hashCode() : 0;
+    }
+
     private static final Logger LOGGER = Logger.getLogger(CopyOnWriteList.class.getName());
 }
diff --git a/hudson-core/src/test/java/hudson/util/CopyOnWriteListEqualsHashCodeTest.java b/hudson-core/src/test/java/hudson/util/CopyOnWriteListEqualsHashCodeTest.java
new file mode 100644
index 0000000..2a38566
--- a/dev/null
+++ b/hudson-core/src/test/java/hudson/util/CopyOnWriteListEqualsHashCodeTest.java
@@ -0,0 +1,73 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2011 Oracle Corporation.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *
+ *   Nikita Levyankov
+ *
+ *
+ *******************************************************************************/
+package hudson.util;
+
+import hudson.tasks.Builder;
+import hudson.tasks.Shell;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Before;
+import org.junit.Test;
+
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertFalse;
+
+/**
+ * Verify equals and hashCode methods for CopyOnWriteList object.
+ * <p/>
+ * Date: 10/5/11
+ *
+ * @author Nikita Levyankov
+ */
+public class CopyOnWriteListEqualsHashCodeTest {
+    private List<Builder> data1;
+    private List<Builder> data2;
+
+    @Before
+    public void setUp() {
+        data1 = new ArrayList<Builder>();
+        data1.add(new Shell("echo 'test'"));
+        data1.add(new Shell("echo 'test1'"));
+        data1.add(new Shell("echo 'test2'"));
+
+        data2 = new ArrayList<Builder>();
+        data2.add(new Shell("echo 'test1'"));
+        data2.add(new Shell("echo 'test'"));
+    }
+
+    @Test
+    public void testHashCode() {
+        assertEquals(new CopyOnWriteList(data1).hashCode(), new CopyOnWriteList(data1).hashCode());
+
+        assertFalse(new CopyOnWriteList(data1).hashCode() == new CopyOnWriteList(data2).hashCode());
+        data2.add(new Shell("echo 'test2'"));
+        assertFalse(new CopyOnWriteList(data1).hashCode() == new CopyOnWriteList(data2).hashCode());
+    }
+
+    @Test
+    public void testEqual() {
+        CopyOnWriteList list = new CopyOnWriteList();
+        assertEquals(list, list);
+        assertFalse(list.equals(null));
+        assertFalse(list.equals(new Object()));
+        assertEquals(new CopyOnWriteList(new ArrayList()), new CopyOnWriteList(new ArrayList()));
+
+        assertFalse(new CopyOnWriteList(data1).equals(new CopyOnWriteList(data2)));
+        assertEquals(new CopyOnWriteList(data1), new CopyOnWriteList(data1));
+        data2.add(new Shell("echo 'test2'"));
+        assertEquals(new CopyOnWriteList(data1), new CopyOnWriteList(data2));
+    }
+}