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;
023import static com.google.common.collect.testing.testers.ReflectionFreeAssertThrows.assertThrows;
024
025import com.google.common.annotations.GwtCompatible;
026import com.google.common.collect.testing.AbstractMapTester;
027import com.google.common.collect.testing.features.CollectionSize;
028import com.google.common.collect.testing.features.MapFeature;
029import java.util.ConcurrentModificationException;
030import java.util.Iterator;
031import java.util.Map.Entry;
032import org.junit.Ignore;
033
034/**
035 * A generic JUnit test which tests {@code clear()} operations on a map. Can't be invoked directly;
036 * please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
037 *
038 * @author George van den Driessche
039 * @author Chris Povirk
040 */
041@GwtCompatible
042@Ignore("test runners must not instantiate and run this directly, only via suites we build")
043// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
044@SuppressWarnings("JUnit4ClassUsedInJUnit3")
045public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
046  @MapFeature.Require(SUPPORTS_REMOVE)
047  public void testClear() {
048    getMap().clear();
049    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
050    assertEquals(0, getMap().size());
051    assertFalse(getMap().entrySet().iterator().hasNext());
052  }
053
054  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
055  @CollectionSize.Require(SEVERAL)
056  public void testClearConcurrentWithEntrySetIteration() {
057    assertThrows(
058        ConcurrentModificationException.class,
059        () -> {
060          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
061          getMap().clear();
062          iterator.next();
063        });
064  }
065
066  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
067  @CollectionSize.Require(SEVERAL)
068  public void testClearConcurrentWithKeySetIteration() {
069    assertThrows(
070        ConcurrentModificationException.class,
071        () -> {
072          Iterator<K> iterator = getMap().keySet().iterator();
073          getMap().clear();
074          iterator.next();
075        });
076  }
077
078  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
079  @CollectionSize.Require(SEVERAL)
080  public void testClearConcurrentWithValuesIteration() {
081    assertThrows(
082        ConcurrentModificationException.class,
083        () -> {
084          Iterator<V> iterator = getMap().values().iterator();
085          getMap().clear();
086          iterator.next();
087        });
088  }
089
090  @MapFeature.Require(absent = SUPPORTS_REMOVE)
091  @CollectionSize.Require(absent = ZERO)
092  public void testClear_unsupported() {
093    assertThrows(UnsupportedOperationException.class, () -> getMap().clear());
094    expectUnchanged();
095  }
096
097  @MapFeature.Require(absent = SUPPORTS_REMOVE)
098  @CollectionSize.Require(ZERO)
099  public void testClear_unsupportedByEmptyCollection() {
100    try {
101      getMap().clear();
102    } catch (UnsupportedOperationException tolerated) {
103    }
104    expectUnchanged();
105  }
106}