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.Helpers.copyToList;
020import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
021
022import com.google.common.annotations.GwtCompatible;
023import com.google.common.collect.testing.MinimalSet;
024import com.google.common.collect.testing.features.CollectionFeature;
025import com.google.common.collect.testing.features.CollectionSize;
026import java.util.Collection;
027import java.util.Set;
028import org.junit.Ignore;
029
030/**
031 * Tests {@link java.util.Set#equals}.
032 *
033 * @author George van den Driessche
034 */
035@GwtCompatible
036@Ignore("test runners must not instantiate and run this directly, only via suites we build")
037// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
038@SuppressWarnings("JUnit4ClassUsedInJUnit3")
039public class SetEqualsTester<E> extends AbstractSetTester<E> {
040  public void testEquals_otherSetWithSameElements() {
041    assertTrue(
042        "A Set should equal any other Set containing the same elements.",
043        getSet().equals(MinimalSet.from(getSampleElements())));
044  }
045
046  @CollectionSize.Require(absent = CollectionSize.ZERO)
047  public void testEquals_otherSetWithDifferentElements() {
048    Collection<E> elements = getSampleElements(getNumElements() - 1);
049    elements.add(getSubjectGenerator().samples().e3());
050
051    assertFalse(
052        "A Set should not equal another Set containing different elements.",
053        getSet().equals(MinimalSet.from(elements)));
054  }
055
056  @CollectionSize.Require(absent = CollectionSize.ZERO)
057  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
058  public void testEquals_containingNull() {
059    Collection<E> elements = getSampleElements(getNumElements() - 1);
060    elements.add(null);
061
062    collection = getSubjectGenerator().create(elements.toArray());
063    assertTrue(
064        "A Set should equal any other Set containing the same elements,"
065            + " even if some elements are null.",
066        getSet().equals(MinimalSet.from(elements)));
067  }
068
069  @CollectionSize.Require(absent = CollectionSize.ZERO)
070  public void testEquals_otherContainsNull() {
071    Collection<E> elements = getSampleElements(getNumElements() - 1);
072    elements.add(null);
073    Set<E> other = MinimalSet.from(elements);
074
075    assertFalse(
076        "Two Sets should not be equal if exactly one of them contains null.",
077        getSet().equals(other));
078  }
079
080  @CollectionSize.Require(absent = CollectionSize.ZERO)
081  public void testEquals_smallerSet() {
082    Collection<E> fewerElements = getSampleElements(getNumElements() - 1);
083    assertFalse(
084        "Sets of different sizes should not be equal.",
085        getSet().equals(MinimalSet.from(fewerElements)));
086  }
087
088  public void testEquals_largerSet() {
089    Collection<E> moreElements = getSampleElements(getNumElements() + 1);
090    assertFalse(
091        "Sets of different sizes should not be equal.",
092        getSet().equals(MinimalSet.from(moreElements)));
093  }
094
095  public void testEquals_list() {
096    assertFalse("A List should never equal a Set.", getSet().equals(copyToList(getSet())));
097  }
098}