1 /* 2 * Copyright (C) 2008 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.collect.testing.testers; 18 19 import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER; 20 import static com.google.common.collect.testing.features.CollectionSize.ONE; 21 import static com.google.common.collect.testing.features.CollectionSize.SEVERAL; 22 import static com.google.common.collect.testing.features.CollectionSize.ZERO; 23 24 import com.google.common.annotations.GwtCompatible; 25 import com.google.common.collect.testing.features.CollectionFeature; 26 import com.google.common.collect.testing.features.CollectionSize; 27 28 /** 29 * A generic JUnit test which tests {@code peek()} operations on a queue. 30 * Can't be invoked directly; please see 31 * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}. 32 * 33 * @author Jared Levy 34 */ 35 @GwtCompatible 36 public class QueuePeekTester<E> extends AbstractQueueTester<E> { 37 @CollectionSize.Require(ZERO) 38 public void testPeek_empty() { 39 assertNull("emptyQueue.peek() should return null", getQueue().peek()); 40 expectUnchanged(); 41 } 42 43 @CollectionSize.Require(ONE) 44 public void testPeek_size1() { 45 assertEquals("size1Queue.peek() should return first element", 46 samples.e0, getQueue().peek()); 47 expectUnchanged(); 48 } 49 50 @CollectionFeature.Require(KNOWN_ORDER) 51 @CollectionSize.Require(SEVERAL) 52 public void testPeek_sizeMany() { 53 assertEquals("sizeManyQueue.peek() should return first element", 54 samples.e0, getQueue().peek()); 55 expectUnchanged(); 56 } 57 } 58