ListEqualsTester.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.MinimalSet;
23import com.google.common.collect.testing.features.CollectionFeature;
24import com.google.common.collect.testing.features.CollectionSize;
25
26import java.util.ArrayList;
27import java.util.Collection;
28import java.util.List;
29
30/**
31 * Tests {@link List#equals}.
32 *
33 * <p>This class is GWT compatible.
34 *
35 * @author George van den Driessche
36 */
37@GwtCompatible
38public class ListEqualsTester<E> extends AbstractListTester<E> {
39  public void testEquals_otherListWithSameElements() {
40    assertTrue(
41        "A List should equal any other List containing the same elements.",
42        getList().equals(new ArrayList<E>(getOrderedElements())));
43  }
44
45  @CollectionSize.Require(absent = CollectionSize.ZERO)
46  public void testEquals_otherListWithDifferentElements() {
47    ArrayList<E> other = new ArrayList<E>(getSampleElements());
48    other.set(other.size() / 2, getSubjectGenerator().samples().e3);
49    assertFalse(
50        "A List should not equal another List containing different elements.",
51        getList().equals(other));
52  }
53
54  @CollectionSize.Require(absent = CollectionSize.ZERO)
55  public void testEquals_otherListContainingNull() {
56    List<E> other = new ArrayList<E>(getSampleElements());
57    other.set(other.size() / 2, null);
58    assertFalse("Two Lists should not be equal if exactly one of them has "
59        + "null at a given index.",
60        getList().equals(other));
61  }
62
63  @CollectionSize.Require(absent = CollectionSize.ZERO)
64  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
65  public void testEquals_containingNull() {
66    ArrayList<E> elements = new ArrayList<E>(getSampleElements());
67    elements.set(elements.size() / 2, null);
68    collection = getSubjectGenerator().create(elements.toArray());
69    List<E> other = new ArrayList<E>(getSampleElements());
70    assertFalse("Two Lists should not be equal if exactly one of them has "
71        + "null at a given index.",
72        getList().equals(other));
73  }
74
75  @CollectionSize.Require(absent = CollectionSize.ZERO)
76  public void testEquals_shorterList() {
77    Collection<E> fewerElements = getSampleElements(getNumElements() - 1);
78    assertFalse("Lists of different sizes should not be equal.",
79        getList().equals(new ArrayList<E>(fewerElements)));
80  }
81
82  public void testEquals_longerList() {
83    Collection<E> moreElements = getSampleElements(getNumElements() + 1);
84    assertFalse("Lists of different sizes should not be equal.",
85        getList().equals(new ArrayList<E>(moreElements)));
86  }
87
88  public void testEquals_set() {
89    assertFalse("A List should never equal a Set.",
90        getList().equals(MinimalSet.from(getList())));
91  }
92}
93