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.CollectionSize.ZERO;
20import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
21import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_QUERIES;
22import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
23
24import com.google.common.collect.testing.AbstractMapTester;
25import com.google.common.collect.testing.WrongType;
26import com.google.common.collect.testing.features.CollectionSize;
27import com.google.common.collect.testing.features.MapFeature;
28
29/**
30 * A generic JUnit test which tests {@code remove} operations on a map. Can't be
31 * invoked directly; please see
32 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
33 *
34 * <p>This class is GWT compatible.
35 *
36 * @author George van den Driessche
37 * @author Chris Povirk
38 */
39@SuppressWarnings("unchecked") // too many "unchecked generic array creations"
40public class MapRemoveTester<K, V> extends AbstractMapTester<K, V> {
41  @MapFeature.Require(SUPPORTS_REMOVE)
42  @CollectionSize.Require(absent = ZERO)
43  public void testRemove_present() {
44    int initialSize = getMap().size();
45    assertEquals("remove(present) should return the associated value",
46        samples.e0.getValue(), getMap().remove(samples.e0.getKey()));
47    assertEquals("remove(present) should decrease a map's size by one.",
48        initialSize - 1, getMap().size());
49    expectMissing(samples.e0);
50  }
51
52  @MapFeature.Require(SUPPORTS_REMOVE)
53  public void testRemove_notPresent() {
54    assertNull("remove(notPresent) should return null",
55        getMap().remove(samples.e3.getKey()));
56    expectUnchanged();
57  }
58
59  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
60  @CollectionSize.Require(absent = ZERO)
61  public void testRemove_nullPresent() {
62    initMapWithNullKey();
63
64    int initialSize = getMap().size();
65    assertEquals("remove(null) should return the associated value",
66        getValueForNullKey(), getMap().remove(null));
67    assertEquals("remove(present) should decrease a map's size by one.",
68        initialSize - 1, getMap().size());
69    expectMissing(entry(null, getValueForNullKey()));
70  }
71
72  @MapFeature.Require(absent = SUPPORTS_REMOVE)
73  @CollectionSize.Require(absent = ZERO)
74  public void testRemove_unsupported() {
75    try {
76      getMap().remove(samples.e0.getKey());
77      fail("remove(present) should throw UnsupportedOperationException");
78    } catch (UnsupportedOperationException expected) {
79    }
80    expectUnchanged();
81    assertEquals("remove(present) should not remove the element",
82        samples.e0.getValue(), get(samples.e0.getKey()));
83  }
84
85  @MapFeature.Require(absent = SUPPORTS_REMOVE)
86  public void testRemove_unsupportedNotPresent() {
87    try {
88      assertNull("remove(notPresent) should return null or throw "
89          + "UnsupportedOperationException",
90          getMap().remove(samples.e3.getKey()));
91    } catch (UnsupportedOperationException tolerated) {
92    }
93    expectUnchanged();
94    expectMissing(samples.e3);
95  }
96
97  @MapFeature.Require(
98      value = SUPPORTS_REMOVE,
99      absent = ALLOWS_NULL_QUERIES)
100  public void testRemove_nullQueriesNotSupported() {
101    try {
102      assertNull("remove(null) should return null or throw "
103          + "NullPointerException",
104          getMap().remove(null));
105    } catch (NullPointerException tolerated) {
106    }
107    expectUnchanged();
108  }
109
110  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
111  public void testRemove_nullSupportedMissing() {
112    assertNull("remove(null) should return null", getMap().remove(null));
113    expectUnchanged();
114  }
115
116  @MapFeature.Require(SUPPORTS_REMOVE)
117  public void testRemove_wrongType() {
118    try {
119      assertNull(getMap().remove(WrongType.VALUE));
120    } catch (ClassCastException tolerated) {
121    }
122    expectUnchanged();
123  }
124}
125