Add unit test for QueueUtils.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1540643 13f79535-47bb-0310-9956-ffa450edef68

src/test/java/org/apache/commons/collections4/QueueUtilsTest.java

@@ -0,0 +1,113 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.commons.collections4;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+import junit.framework.Test;
+
+import org.apache.commons.collections4.Predicate;
+import org.apache.commons.collections4.Transformer;
+import org.apache.commons.collections4.TransformerUtils;
+import org.apache.commons.collections4.functors.TruePredicate;
+import org.apache.commons.collections4.queue.PredicatedQueue;
+import org.apache.commons.collections4.queue.TransformedQueue;
+import org.apache.commons.collections4.queue.UnmodifiableQueue;
+
+/**
+ * Tests for QueueUtils factory methods.
+ * 
+ * @version $Id$
+ */
+public class QueueUtilsTest extends BulkTest {
+
+    public QueueUtilsTest(final String name) {
+        super(name);
+    }
+
+    public static Test suite() {
+        return BulkTest.makeSuite(QueueUtilsTest.class);
+    }
+
+    // ----------------------------------------------------------------------
+
+    protected Class<?> stringClass = this.getName().getClass();
+    protected Predicate<Object> truePredicate = TruePredicate.truePredicate();
+    protected Transformer<Object, Object> nopTransformer = TransformerUtils.nopTransformer();
+
+    // ----------------------------------------------------------------------
+
+    public void testUnmodifiableQueue() {
+        Queue<Object> queue = QueueUtils.unmodifiableQueue(new LinkedList<Object>());
+        assertTrue("Returned object should be an UnmodifiableQueue.", queue instanceof UnmodifiableQueue);
+        try {
+            QueueUtils.unmodifiableQueue(null);
+            fail("Expecting IllegalArgumentException for null queue.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+    }
+
+    public void testPredicatedQueue() {
+        Queue<Object> queue = QueueUtils.predicatedQueue(new LinkedList<Object>(), truePredicate);
+        assertTrue("Returned object should be a PredicatedQueue.", queue instanceof PredicatedQueue);
+        try {
+            QueueUtils.predicatedQueue(null, truePredicate);
+            fail("Expecting IllegalArgumentException for null queue.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+        try {
+            QueueUtils.predicatedQueue(new LinkedList<Object>(), null);
+            fail("Expecting IllegalArgumentException for null predicate.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+    }
+
+    public void testTransformedQueue() {
+        Queue<Object> queue = QueueUtils.transformingQueue(new LinkedList<Object>(), nopTransformer);
+        assertTrue("Returned object should be an TransformedQueue.", queue instanceof TransformedQueue);
+        try {
+            QueueUtils.transformingQueue(null, nopTransformer);
+            fail("Expecting IllegalArgumentException for null queue.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+        try {
+            QueueUtils.transformingQueue(new LinkedList<Object>(), null);
+            fail("Expecting IllegalArgumentException for null transformer.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+    }
+
+    public void testEmptyQueue() {
+        Queue<Object> queue = QueueUtils.emptyQueue();
+        assertTrue("Returned object should be an UnmodifiableQueue.", queue instanceof UnmodifiableQueue);
+        assertTrue("Returned queue is not empty.", queue.isEmpty());
+
+        try {
+            queue.add(new Object());
+            fail("Expecting UnsupportedOperationException for empty queue.");
+        } catch (final UnsupportedOperationException ex) {
+            // expected
+        }
+    }
+
+}