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