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.
042public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
043  @MapFeature.Require(SUPPORTS_REMOVE)
044  public void testClear() {
045    getMap().clear();
046    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
047    assertEquals(0, getMap().size());
048    assertFalse(getMap().entrySet().iterator().hasNext());
049  }
050
051  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
052  @CollectionSize.Require(SEVERAL)
053  public void testClearConcurrentWithEntrySetIteration() {
054    try {
055      Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
056      getMap().clear();
057      iterator.next();
058      fail("Expected ConcurrentModificationException");
059    } catch (ConcurrentModificationException expected) {
060      // success
061    }
062  }
063
064  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
065  @CollectionSize.Require(SEVERAL)
066  public void testClearConcurrentWithKeySetIteration() {
067    try {
068      Iterator<K> iterator = getMap().keySet().iterator();
069      getMap().clear();
070      iterator.next();
071      fail("Expected ConcurrentModificationException");
072    } catch (ConcurrentModificationException expected) {
073      // success
074    }
075  }
076
077  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
078  @CollectionSize.Require(SEVERAL)
079  public void testClearConcurrentWithValuesIteration() {
080    try {
081      Iterator<V> iterator = getMap().values().iterator();
082      getMap().clear();
083      iterator.next();
084      fail("Expected ConcurrentModificationException");
085    } catch (ConcurrentModificationException expected) {
086      // success
087    }
088  }
089
090  @MapFeature.Require(absent = SUPPORTS_REMOVE)
091  @CollectionSize.Require(absent = ZERO)
092  public void testClear_unsupported() {
093    try {
094      getMap().clear();
095      fail(
096          "clear() should throw UnsupportedOperation if a map does "
097              + "not support it and is not empty.");
098    } catch (UnsupportedOperationException expected) {
099    }
100    expectUnchanged();
101  }
102
103  @MapFeature.Require(absent = SUPPORTS_REMOVE)
104  @CollectionSize.Require(ZERO)
105  public void testClear_unsupportedByEmptyCollection() {
106    try {
107      getMap().clear();
108    } catch (UnsupportedOperationException tolerated) {
109    }
110    expectUnchanged();
111  }
112}