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_QUERIES;
20import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
21import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
22import static com.google.common.collect.testing.features.CollectionSize.ZERO;
23
24import com.google.common.collect.testing.AbstractCollectionTester;
25import com.google.common.collect.testing.WrongType;
26import com.google.common.collect.testing.features.CollectionFeature;
27import com.google.common.collect.testing.features.CollectionSize;
28
29import java.util.Iterator;
30
31/**
32 * A generic JUnit test which tests {@code remove} operations on a collection.
33 * Can't be invoked directly; please see
34 * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
35 *
36 * <p>This class is GWT compatible.
37 *
38 * @author George van den Driessche
39 */
40@SuppressWarnings("unchecked") // too many "unchecked generic array creations"
41public class CollectionRemoveTester<E> extends AbstractCollectionTester<E> {
42  @CollectionFeature.Require(SUPPORTS_REMOVE)
43  @CollectionSize.Require(absent = ZERO)
44  public void testRemove_present() {
45    int initialSize = collection.size();
46    assertTrue("remove(present) should return true",
47        collection.remove(samples.e0));
48    assertEquals("remove(present) should decrease a collection's size by one.",
49        initialSize - 1, collection.size());
50    expectMissing(samples.e0);
51  }
52
53  @CollectionFeature.Require(SUPPORTS_REMOVE)
54  public void testRemove_notPresent() {
55    assertFalse("remove(notPresent) should return false",
56        collection.remove(samples.e3));
57    expectUnchanged();
58  }
59
60  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
61  @CollectionSize.Require(absent = ZERO)
62  public void testRemove_nullPresent() {
63    collection = getSubjectGenerator().create(createArrayWithNullElement());
64
65    int initialSize = collection.size();
66    assertTrue("remove(null) should return true", collection.remove(null));
67    assertEquals("remove(present) should decrease a collection's size by one.",
68        initialSize - 1, collection.size());
69    expectMissing((E) null);
70  }
71
72  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
73  @CollectionSize.Require(absent = ZERO)
74  public void testRemove_unsupported() {
75    try {
76      collection.remove(samples.e0);
77      fail("remove(present) should throw UnsupportedOperationException");
78    } catch (UnsupportedOperationException expected) {
79    }
80    expectUnchanged();
81    assertTrue("remove(present) should not remove the element",
82        collection.contains(samples.e0));
83  }
84
85  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
86  public void testRemove_unsupportedNotPresent() {
87    try {
88      assertFalse("remove(notPresent) should return false or throw "
89          + "UnsupportedOperationException",
90          collection.remove(samples.e3));
91    } catch (UnsupportedOperationException tolerated) {
92    }
93    expectUnchanged();
94    expectMissing(samples.e3);
95  }
96
97  @CollectionFeature.Require(
98      value = SUPPORTS_REMOVE,
99      absent = ALLOWS_NULL_QUERIES)
100  public void testRemove_nullNotSupported() {
101    try {
102      assertFalse("remove(null) should return false or throw "
103          + "NullPointerException",
104          collection.remove(null));
105    } catch (NullPointerException tolerated) {
106    }
107    expectUnchanged();
108  }
109
110  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
111  public void testRemove_nullAllowed() {
112    assertFalse("remove(null) should return false", collection.remove(null));
113    expectUnchanged();
114  }
115
116  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
117  @CollectionSize.Require(absent = ZERO)
118  public void testIteratorRemove_unsupported() {
119    Iterator<E> iterator = collection.iterator();
120    iterator.next();
121    try {
122      iterator.remove();
123      fail("iterator.remove() should throw UnsupportedOperationException");
124    } catch (UnsupportedOperationException expected) {
125    }
126    expectUnchanged();
127    assertTrue(collection.contains(samples.e0));
128  }
129
130  @CollectionFeature.Require(SUPPORTS_REMOVE)
131  public void testRemove_wrongType() {
132    try {
133      assertFalse(collection.remove(WrongType.VALUE));
134    } catch (ClassCastException tolerated) {
135    }
136    expectUnchanged();
137  }
138}
139