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.collect.testing.Helpers;
22import com.google.common.collect.testing.MinimalSet;
23import com.google.common.collect.testing.features.CollectionFeature;
24import com.google.common.collect.testing.features.CollectionSize;
25
26import java.util.Collection;
27import java.util.Set;
28
29/**
30 * Tests {@link java.util.Set#equals}.
31 *
32 * <p>This class is GWT compatible.
33 *
34 * @author George van den Driessche
35 */
36public class SetEqualsTester<E> extends AbstractSetTester<E> {
37  public void testEquals_otherSetWithSameElements() {
38    assertTrue(
39        "A Set should equal any other Set containing the same elements.",
40        getSet().equals(MinimalSet.from(getSampleElements())));
41  }
42
43  @CollectionSize.Require(absent = CollectionSize.ZERO)
44  public void testEquals_otherSetWithDifferentElements() {
45    Collection<E> elements = getSampleElements(getNumElements() - 1);
46    elements.add(getSubjectGenerator().samples().e3);
47
48    assertFalse(
49        "A Set should not equal another Set containing different elements.",
50        getSet().equals(MinimalSet.from(elements))
51    );
52  }
53
54  @CollectionSize.Require(absent = CollectionSize.ZERO)
55  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
56  public void testEquals_containingNull() {
57    Collection<E> elements = getSampleElements(getNumElements() - 1);
58    elements.add(null);
59
60    collection = getSubjectGenerator().create(elements.toArray());
61    assertTrue("A Set should equal any other Set containing the same elements,"
62        + " even if some elements are null.",
63        getSet().equals(MinimalSet.from(elements)));
64  }
65
66  @CollectionSize.Require(absent = CollectionSize.ZERO)
67  public void testEquals_otherContainsNull() {
68    Collection<E> elements = getSampleElements(getNumElements() - 1);
69    elements.add(null);
70    Set<E> other = MinimalSet.from(elements);
71
72    assertFalse(
73        "Two Sets should not be equal if exactly one of them contains null.",
74        getSet().equals(other));
75  }
76
77  @CollectionSize.Require(absent = CollectionSize.ZERO)
78  public void testEquals_smallerSet() {
79    Collection<E> fewerElements = getSampleElements(getNumElements() - 1);
80    assertFalse("Sets of different sizes should not be equal.",
81        getSet().equals(MinimalSet.from(fewerElements)));
82  }
83
84  public void testEquals_largerSet() {
85    Collection<E> moreElements = getSampleElements(getNumElements() + 1);
86    assertFalse("Sets of different sizes should not be equal.",
87        getSet().equals(MinimalSet.from(moreElements)));
88  }
89
90  public void testEquals_list() {
91    assertFalse("A List should never equal a Set.",
92        getSet().equals(Helpers.copyToList(getSet())));
93  }
94}
95