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.CollectionSize.SEVERAL; 020import static com.google.common.collect.testing.features.CollectionSize.ZERO; 021import static com.google.common.collect.testing.features.MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION; 022import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE; 023 024import com.google.common.annotations.GwtCompatible; 025import com.google.common.collect.testing.AbstractMapTester; 026import com.google.common.collect.testing.features.CollectionSize; 027import com.google.common.collect.testing.features.MapFeature; 028import java.util.ConcurrentModificationException; 029import java.util.Iterator; 030import java.util.Map.Entry; 031 032/** 033 * A generic JUnit test which tests {@code clear()} operations on a map. Can't be invoked directly; 034 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}. 035 * 036 * @author George van den Driessche 037 * @author Chris Povirk 038 */ 039@GwtCompatible 040public class MapClearTester<K, V> extends AbstractMapTester<K, V> { 041 @MapFeature.Require(SUPPORTS_REMOVE) 042 public void testClear() { 043 getMap().clear(); 044 assertTrue("After clear(), a map should be empty.", getMap().isEmpty()); 045 assertEquals(0, getMap().size()); 046 assertFalse(getMap().entrySet().iterator().hasNext()); 047 } 048 049 @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE}) 050 @CollectionSize.Require(SEVERAL) 051 public void testClearConcurrentWithEntrySetIteration() { 052 try { 053 Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator(); 054 getMap().clear(); 055 iterator.next(); 056 fail("Expected ConcurrentModificationException"); 057 } catch (ConcurrentModificationException expected) { 058 // success 059 } 060 } 061 062 @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE}) 063 @CollectionSize.Require(SEVERAL) 064 public void testClearConcurrentWithKeySetIteration() { 065 try { 066 Iterator<K> iterator = getMap().keySet().iterator(); 067 getMap().clear(); 068 iterator.next(); 069 fail("Expected ConcurrentModificationException"); 070 } catch (ConcurrentModificationException expected) { 071 // success 072 } 073 } 074 075 @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE}) 076 @CollectionSize.Require(SEVERAL) 077 public void testClearConcurrentWithValuesIteration() { 078 try { 079 Iterator<V> iterator = getMap().values().iterator(); 080 getMap().clear(); 081 iterator.next(); 082 fail("Expected ConcurrentModificationException"); 083 } catch (ConcurrentModificationException expected) { 084 // success 085 } 086 } 087 088 @MapFeature.Require(absent = SUPPORTS_REMOVE) 089 @CollectionSize.Require(absent = ZERO) 090 public void testClear_unsupported() { 091 try { 092 getMap().clear(); 093 fail( 094 "clear() should throw UnsupportedOperation if a map does " 095 + "not support it and is not empty."); 096 } catch (UnsupportedOperationException expected) { 097 } 098 expectUnchanged(); 099 } 100 101 @MapFeature.Require(absent = SUPPORTS_REMOVE) 102 @CollectionSize.Require(ZERO) 103 public void testClear_unsupportedByEmptyCollection() { 104 try { 105 getMap().clear(); 106 } catch (UnsupportedOperationException tolerated) { 107 } 108 expectUnchanged(); 109 } 110}