001/*
002 * Copyright (C) 2015 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_ITERATOR_REMOVE;
021import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
022import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
023import static com.google.common.collect.testing.features.CollectionSize.ZERO;
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.Collection;
030import java.util.ConcurrentModificationException;
031import java.util.Iterator;
032import java.util.function.Predicate;
033import org.junit.Ignore;
034
035/**
036 * A generic JUnit test which tests {@link Collection#removeIf}. Can't be invoked directly; please
037 * see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
038 *
039 * @author Louis Wasserman
040 */
041@GwtCompatible
042@SuppressWarnings("unchecked") // too many "unchecked generic array creations"
043@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
044public class CollectionRemoveIfTester<E> extends AbstractCollectionTester<E> {
045  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
046  public void testRemoveIf_alwaysFalse() {
047    assertFalse("removeIf(x -> false) should return false", collection.removeIf(x -> false));
048    expectUnchanged();
049  }
050
051  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
052  @CollectionSize.Require(absent = ZERO)
053  public void testRemoveIf_sometimesTrue() {
054    assertTrue(
055        "removeIf(isEqual(present)) should return true",
056        collection.removeIf(Predicate.isEqual(samples.e0())));
057    expectMissing(samples.e0());
058  }
059
060  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
061  @CollectionSize.Require(absent = ZERO)
062  public void testRemoveIf_allPresent() {
063    assertTrue("removeIf(x -> true) should return true", collection.removeIf(x -> true));
064    expectContents();
065  }
066
067  @CollectionFeature.Require({SUPPORTS_ITERATOR_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
068  @CollectionSize.Require(SEVERAL)
069  public void testRemoveIfSomeMatchesConcurrentWithIteration() {
070    try {
071      Iterator<E> iterator = collection.iterator();
072      assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));
073      iterator.next();
074      fail("Expected ConcurrentModificationException");
075    } catch (ConcurrentModificationException expected) {
076      // success
077    }
078  }
079
080  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
081  @CollectionSize.Require(ZERO)
082  public void testRemoveIf_unsupportedEmptyCollection() {
083    try {
084      assertFalse(
085          "removeIf(Predicate) should return false or throw " + "UnsupportedOperationException",
086          collection.removeIf(
087              x -> {
088                throw new AssertionError("predicate should never be called");
089              }));
090    } catch (UnsupportedOperationException tolerated) {
091    }
092    expectUnchanged();
093  }
094
095  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
096  @CollectionSize.Require(absent = ZERO)
097  public void testRemoveIf_alwaysTrueUnsupported() {
098    try {
099      collection.removeIf(x -> true);
100      fail("removeIf(x -> true) should throw " + "UnsupportedOperationException");
101    } catch (UnsupportedOperationException expected) {
102    }
103    expectUnchanged();
104    assertTrue(collection.contains(samples.e0()));
105  }
106}