MultisetRemoveTester.java revision 0888a09821a98ac0680fad765217302858e70fa4 
1/*
2 * Copyright (C) 2013 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.google;
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.SEVERAL;
23import static com.google.common.collect.testing.features.CollectionSize.ZERO;
24import static org.truth0.Truth.ASSERT;
25
26import com.google.common.annotations.GwtCompatible;
27import com.google.common.annotations.GwtIncompatible;
28import com.google.common.collect.testing.Helpers;
29import com.google.common.collect.testing.WrongType;
30import com.google.common.collect.testing.features.CollectionFeature;
31import com.google.common.collect.testing.features.CollectionSize;
32
33import java.lang.reflect.Method;
34import java.util.Arrays;
35import java.util.Collections;
36import java.util.List;
37
38/**
39 * Tests for {@code Multiset#remove}, {@code Multiset.removeAll}, and {@code Multiset.retainAll}
40 * not already covered by the corresponding Collection testers.
41 *
42 * @author Jared Levy
43 */
44@GwtCompatible(emulated = true)
45public class MultisetRemoveTester<E> extends AbstractMultisetTester<E> {
46  @CollectionFeature.Require(SUPPORTS_REMOVE)
47  public void testRemoveNegative() {
48    try {
49      getMultiset().remove(samples.e0, -1);
50      fail("Expected IllegalArgumentException");
51    } catch (IllegalArgumentException expected) {}
52    expectUnchanged();
53  }
54
55  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
56  public void testRemoveUnsupported() {
57    try {
58      getMultiset().remove(samples.e0, 2);
59      fail("Expected UnsupportedOperationException");
60    } catch (UnsupportedOperationException expected) {}
61  }
62
63  @CollectionFeature.Require(SUPPORTS_REMOVE)
64  public void testRemoveZeroNoOp() {
65    int originalCount = getMultiset().count(samples.e0);
66    assertEquals("old count", originalCount, getMultiset().remove(samples.e0, 0));
67    expectUnchanged();
68  }
69
70  @CollectionSize.Require(absent = ZERO)
71  @CollectionFeature.Require(SUPPORTS_REMOVE)
72  public void testRemove_occurrences_present() {
73    assertEquals("multiset.remove(present, 2) didn't return the old count",
74        1, getMultiset().remove(samples.e0, 2));
75    assertFalse("multiset contains present after multiset.remove(present, 2)",
76        getMultiset().contains(samples.e0));
77    assertEquals(0, getMultiset().count(samples.e0));
78  }
79
80  @CollectionSize.Require(SEVERAL)
81  @CollectionFeature.Require(SUPPORTS_REMOVE)
82  public void testRemove_some_occurrences_present() {
83    initThreeCopies();
84    assertEquals("multiset.remove(present, 2) didn't return the old count",
85        3, getMultiset().remove(samples.e0, 2));
86    assertTrue("multiset contains present after multiset.remove(present, 2)",
87        getMultiset().contains(samples.e0));
88    assertEquals(1, getMultiset().count(samples.e0));
89  }
90
91  @CollectionFeature.Require(SUPPORTS_REMOVE)
92  public void testRemove_occurrences_absent() {
93    assertEquals("multiset.remove(absent, 0) didn't return 0",
94        0, getMultiset().remove(samples.e3, 2));
95  }
96
97  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
98  public void testRemove_occurrences_unsupported_absent() {
99    // notice: we don't care whether it succeeds, or fails with UOE
100    try {
101      assertEquals(
102          "multiset.remove(absent, 2) didn't return 0 or throw an exception",
103          0, getMultiset().remove(samples.e3, 2));
104    } catch (UnsupportedOperationException ok) {}
105  }
106
107  @CollectionFeature.Require(SUPPORTS_REMOVE)
108  public void testRemove_occurrences_0() {
109    int oldCount = getMultiset().count(samples.e0);
110    assertEquals("multiset.remove(E, 0) didn't return the old count",
111        oldCount, getMultiset().remove(samples.e0, 0));
112  }
113
114  @CollectionFeature.Require(SUPPORTS_REMOVE)
115  public void testRemove_occurrences_negative() {
116    try {
117      getMultiset().remove(samples.e0, -1);
118      fail("multiset.remove(E, -1) didn't throw an exception");
119    } catch (IllegalArgumentException required) {}
120  }
121
122  @CollectionFeature.Require(SUPPORTS_REMOVE)
123  public void testRemove_occurrences_wrongType() {
124    assertEquals("multiset.remove(wrongType, 1) didn't return 0",
125        0, getMultiset().remove(WrongType.VALUE, 1));
126  }
127
128  @CollectionSize.Require(absent = ZERO)
129  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
130  public void testRemove_nullPresent() {
131    initCollectionWithNullElement();
132    assertEquals(1, getMultiset().remove(null, 2));
133    assertFalse("multiset contains present after multiset.remove(present, 2)",
134        getMultiset().contains(null));
135    assertEquals(0, getMultiset().count(null));
136  }
137
138  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
139  public void testRemove_nullAbsent() {
140    assertEquals(0, getMultiset().remove(null, 2));
141  }
142
143  @CollectionFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_QUERIES)
144  public void testRemove_nullForbidden() {
145    try {
146      getMultiset().remove(null, 2);
147      fail("Expected NullPointerException");
148    } catch (NullPointerException expected) {}
149  }
150
151  @CollectionSize.Require(SEVERAL)
152  @CollectionFeature.Require(SUPPORTS_REMOVE)
153  public void testRemoveAllIgnoresCount() {
154    initThreeCopies();
155    assertTrue(getMultiset().removeAll(Collections.singleton(samples.e0)));
156    ASSERT.that(getMultiset()).isEmpty();
157  }
158
159  @CollectionSize.Require(SEVERAL)
160  @CollectionFeature.Require(SUPPORTS_REMOVE)
161  public void testRetainAllIgnoresCount() {
162    initThreeCopies();
163    List<E> contents = Helpers.copyToList(getMultiset());
164    assertFalse(getMultiset().retainAll(Collections.singleton(samples.e0)));
165    expectContents(contents);
166  }
167
168  /**
169   * Returns {@link Method} instances for the remove tests that assume multisets
170   * support duplicates so that the test of {@code Multisets.forSet()} can
171   * suppress them.
172   */
173  @GwtIncompatible("reflection")
174  public static List<Method> getRemoveDuplicateInitializingMethods() {
175    return Arrays.asList(
176        Helpers.getMethod(MultisetRemoveTester.class, "testRemove_some_occurrences_present"));
177  }
178}
179