SetEqualsTester.java revision 7dd252788645e940eada959bdde927426e2531c9 
1/*
2 * Copyright (C) 2008 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect.testing.testers;
18
19import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
20
21import com.google.common.annotations.GwtCompatible;
22import com.google.common.collect.testing.Helpers;
23import com.google.common.collect.testing.MinimalSet;
24import com.google.common.collect.testing.features.CollectionFeature;
25import com.google.common.collect.testing.features.CollectionSize;
26
27import java.util.Collection;
28import java.util.Set;
29
30/**
31 * Tests {@link java.util.Set#equals}.
32 *
33 * <p>This class is GWT compatible.
34 *
35 * @author George van den Driessche
36 */
37@GwtCompatible
38public class SetEqualsTester<E> extends AbstractSetTester<E> {
39  public void testEquals_otherSetWithSameElements() {
40    assertTrue(
41        "A Set should equal any other Set containing the same elements.",
42        getSet().equals(MinimalSet.from(getSampleElements())));
43  }
44
45  @CollectionSize.Require(absent = CollectionSize.ZERO)
46  public void testEquals_otherSetWithDifferentElements() {
47    Collection<E> elements = getSampleElements(getNumElements() - 1);
48    elements.add(getSubjectGenerator().samples().e3);
49
50    assertFalse(
51        "A Set should not equal another Set containing different elements.",
52        getSet().equals(MinimalSet.from(elements))
53    );
54  }
55
56  @CollectionSize.Require(absent = CollectionSize.ZERO)
57  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
58  public void testEquals_containingNull() {
59    Collection<E> elements = getSampleElements(getNumElements() - 1);
60    elements.add(null);
61
62    collection = getSubjectGenerator().create(elements.toArray());
63    assertTrue("A Set should equal any other Set containing the same elements,"
64        + " even if some elements are null.",
65        getSet().equals(MinimalSet.from(elements)));
66  }
67
68  @CollectionSize.Require(absent = CollectionSize.ZERO)
69  public void testEquals_otherContainsNull() {
70    Collection<E> elements = getSampleElements(getNumElements() - 1);
71    elements.add(null);
72    Set<E> other = MinimalSet.from(elements);
73
74    assertFalse(
75        "Two Sets should not be equal if exactly one of them contains null.",
76        getSet().equals(other));
77  }
78
79  @CollectionSize.Require(absent = CollectionSize.ZERO)
80  public void testEquals_smallerSet() {
81    Collection<E> fewerElements = getSampleElements(getNumElements() - 1);
82    assertFalse("Sets of different sizes should not be equal.",
83        getSet().equals(MinimalSet.from(fewerElements)));
84  }
85
86  public void testEquals_largerSet() {
87    Collection<E> moreElements = getSampleElements(getNumElements() + 1);
88    assertFalse("Sets of different sizes should not be equal.",
89        getSet().equals(MinimalSet.from(moreElements)));
90  }
91
92  public void testEquals_list() {
93    assertFalse("A List should never equal a Set.",
94        getSet().equals(Helpers.copyToList(getSet())));
95  }
96}
97