001/* 002 * Copyright (C) 2008 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.collect.testing.testers; 018 019import static com.google.common.collect.testing.features.CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION; 020import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE; 021import static com.google.common.collect.testing.features.CollectionSize.SEVERAL; 022import static com.google.common.collect.testing.features.CollectionSize.ZERO; 023import static com.google.common.collect.testing.testers.ReflectionFreeAssertThrows.assertThrows; 024 025import com.google.common.annotations.GwtCompatible; 026import com.google.common.collect.testing.AbstractCollectionTester; 027import com.google.common.collect.testing.features.CollectionFeature; 028import com.google.common.collect.testing.features.CollectionSize; 029import java.util.ConcurrentModificationException; 030import java.util.Iterator; 031import org.junit.Ignore; 032 033/** 034 * A generic JUnit test which tests {@code clear()} operations on a collection. Can't be invoked 035 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}. 036 * 037 * @author George van den Driessche 038 */ 039@GwtCompatible 040@Ignore("test runners must not instantiate and run this directly, only via suites we build") 041// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests. 042@SuppressWarnings("JUnit4ClassUsedInJUnit3") 043public class CollectionClearTester<E> extends AbstractCollectionTester<E> { 044 @CollectionFeature.Require(SUPPORTS_REMOVE) 045 public void testClear() { 046 collection.clear(); 047 assertTrue("After clear(), a collection should be empty.", collection.isEmpty()); 048 assertEquals(0, collection.size()); 049 assertFalse(collection.iterator().hasNext()); 050 } 051 052 @CollectionFeature.Require(absent = SUPPORTS_REMOVE) 053 @CollectionSize.Require(absent = ZERO) 054 public void testClear_unsupported() { 055 assertThrows(UnsupportedOperationException.class, () -> collection.clear()); 056 expectUnchanged(); 057 } 058 059 @CollectionFeature.Require(absent = SUPPORTS_REMOVE) 060 @CollectionSize.Require(ZERO) 061 public void testClear_unsupportedByEmptyCollection() { 062 try { 063 collection.clear(); 064 } catch (UnsupportedOperationException tolerated) { 065 } 066 expectUnchanged(); 067 } 068 069 @CollectionFeature.Require({SUPPORTS_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION}) 070 @CollectionSize.Require(SEVERAL) 071 public void testClearConcurrentWithIteration() { 072 assertThrows( 073 ConcurrentModificationException.class, 074 () -> { 075 Iterator<E> iterator = collection.iterator(); 076 collection.clear(); 077 iterator.next(); 078 }); 079 } 080}