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;
031import org.junit.Ignore;
032
033/**
034 * A generic JUnit test which tests {@code clear()} operations on a map. Can't be invoked directly;
035 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
036 *
037 * @author George van den Driessche
038 * @author Chris Povirk
039 */
040@GwtCompatible
041@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
042@SuppressWarnings("JUnit4ClassUsedInJUnit3")
043public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
044  @MapFeature.Require(SUPPORTS_REMOVE)
045  public void testClear() {
046    getMap().clear();
047    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
048    assertEquals(0, getMap().size());
049    assertFalse(getMap().entrySet().iterator().hasNext());
050  }
051
052  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
053  @CollectionSize.Require(SEVERAL)
054  public void testClearConcurrentWithEntrySetIteration() {
055    try {
056      Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
057      getMap().clear();
058      iterator.next();
059      fail("Expected ConcurrentModificationException");
060    } catch (ConcurrentModificationException expected) {
061      // success
062    }
063  }
064
065  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
066  @CollectionSize.Require(SEVERAL)
067  public void testClearConcurrentWithKeySetIteration() {
068    try {
069      Iterator<K> iterator = getMap().keySet().iterator();
070      getMap().clear();
071      iterator.next();
072      fail("Expected ConcurrentModificationException");
073    } catch (ConcurrentModificationException expected) {
074      // success
075    }
076  }
077
078  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
079  @CollectionSize.Require(SEVERAL)
080  public void testClearConcurrentWithValuesIteration() {
081    try {
082      Iterator<V> iterator = getMap().values().iterator();
083      getMap().clear();
084      iterator.next();
085      fail("Expected ConcurrentModificationException");
086    } catch (ConcurrentModificationException expected) {
087      // success
088    }
089  }
090
091  @MapFeature.Require(absent = SUPPORTS_REMOVE)
092  @CollectionSize.Require(absent = ZERO)
093  public void testClear_unsupported() {
094    try {
095      getMap().clear();
096      fail(
097          "clear() should throw UnsupportedOperation if a map does "
098              + "not support it and is not empty.");
099    } catch (UnsupportedOperationException expected) {
100    }
101    expectUnchanged();
102  }
103
104  @MapFeature.Require(absent = SUPPORTS_REMOVE)
105  @CollectionSize.Require(ZERO)
106  public void testClear_unsupportedByEmptyCollection() {
107    try {
108      getMap().clear();
109    } catch (UnsupportedOperationException tolerated) {
110    }
111    expectUnchanged();
112  }
113}