001/*
002 * Copyright (C) 2013 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.collect.testing.google;
018
019import static com.google.common.collect.testing.Helpers.assertEmpty;
020import static com.google.common.collect.testing.Helpers.copyToList;
021import static com.google.common.collect.testing.Helpers.getMethod;
022import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_QUERIES;
023import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
024import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
025import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
026import static com.google.common.collect.testing.features.CollectionSize.ZERO;
027import static java.util.Arrays.asList;
028import static java.util.Collections.singleton;
029import static org.junit.Assert.assertThrows;
030
031import com.google.common.annotations.GwtCompatible;
032import com.google.common.annotations.GwtIncompatible;
033import com.google.common.annotations.J2ktIncompatible;
034import com.google.common.collect.testing.WrongType;
035import com.google.common.collect.testing.features.CollectionFeature;
036import com.google.common.collect.testing.features.CollectionSize;
037import java.lang.reflect.Method;
038import java.util.List;
039
040/**
041 * Tests for {@code Multiset#remove}, {@code Multiset.removeAll}, and {@code Multiset.retainAll} not
042 * already covered by the corresponding Collection testers.
043 *
044 * @author Jared Levy
045 */
046@GwtCompatible
047public class MultisetRemoveTester<E> extends AbstractMultisetTester<E> {
048  @CollectionFeature.Require(SUPPORTS_REMOVE)
049  public void testRemoveNegative() {
050    assertThrows(IllegalArgumentException.class, () -> getMultiset().remove(e0(), -1));
051    expectUnchanged();
052  }
053
054  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
055  public void testRemoveUnsupported() {
056    assertThrows(UnsupportedOperationException.class, () -> getMultiset().remove(e0(), 2));
057  }
058
059  @CollectionFeature.Require(SUPPORTS_REMOVE)
060  public void testRemoveZeroNoOp() {
061    int originalCount = getMultiset().count(e0());
062    assertEquals("old count", originalCount, getMultiset().remove(e0(), 0));
063    expectUnchanged();
064  }
065
066  @CollectionSize.Require(absent = ZERO)
067  @CollectionFeature.Require(SUPPORTS_REMOVE)
068  public void testRemove_occurrences_present() {
069    assertEquals(
070        "multiset.remove(present, 2) didn't return the old count",
071        1,
072        getMultiset().remove(e0(), 2));
073    assertFalse(
074        "multiset contains present after multiset.remove(present, 2)",
075        getMultiset().contains(e0()));
076    assertEquals(0, getMultiset().count(e0()));
077  }
078
079  @CollectionSize.Require(SEVERAL)
080  @CollectionFeature.Require(SUPPORTS_REMOVE)
081  public void testRemove_some_occurrences_present() {
082    initThreeCopies();
083    assertEquals(
084        "multiset.remove(present, 2) didn't return the old count",
085        3,
086        getMultiset().remove(e0(), 2));
087    assertTrue(
088        "multiset contains present after multiset.remove(present, 2)",
089        getMultiset().contains(e0()));
090    assertEquals(1, getMultiset().count(e0()));
091  }
092
093  @CollectionFeature.Require(SUPPORTS_REMOVE)
094  public void testRemove_occurrences_absent() {
095    int distinct = getMultiset().elementSet().size();
096    assertEquals("multiset.remove(absent, 0) didn't return 0", 0, getMultiset().remove(e3(), 2));
097    assertEquals(distinct, getMultiset().elementSet().size());
098  }
099
100  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
101  public void testRemove_occurrences_unsupported_absent() {
102    // notice: we don't care whether it succeeds, or fails with UOE
103    try {
104      assertEquals(
105          "multiset.remove(absent, 2) didn't return 0 or throw an exception",
106          0,
107          getMultiset().remove(e3(), 2));
108    } catch (UnsupportedOperationException ok) {
109    }
110  }
111
112  @CollectionFeature.Require(SUPPORTS_REMOVE)
113  public void testRemove_occurrences_0() {
114    int oldCount = getMultiset().count(e0());
115    assertEquals(
116        "multiset.remove(E, 0) didn't return the old count",
117        oldCount,
118        getMultiset().remove(e0(), 0));
119  }
120
121  @CollectionFeature.Require(SUPPORTS_REMOVE)
122  public void testRemove_occurrences_negative() {
123    assertThrows(IllegalArgumentException.class, () -> getMultiset().remove(e0(), -1));
124  }
125
126  @CollectionFeature.Require(SUPPORTS_REMOVE)
127  public void testRemove_occurrences_wrongType() {
128    assertEquals(
129        "multiset.remove(wrongType, 1) didn't return 0",
130        0,
131        getMultiset().remove(WrongType.VALUE, 1));
132  }
133
134  @CollectionSize.Require(absent = ZERO)
135  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
136  public void testRemove_nullPresent() {
137    initCollectionWithNullElement();
138    assertEquals(1, getMultiset().remove(null, 2));
139    assertFalse(
140        "multiset contains present after multiset.remove(present, 2)",
141        getMultiset().contains(null));
142    assertEquals(0, getMultiset().count(null));
143  }
144
145  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
146  public void testRemove_nullAbsent() {
147    assertEquals(0, getMultiset().remove(null, 2));
148  }
149
150  @CollectionFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_QUERIES)
151  public void testRemove_nullForbidden() {
152    assertThrows(NullPointerException.class, () -> getMultiset().remove(null, 2));
153  }
154
155  @CollectionSize.Require(SEVERAL)
156  @CollectionFeature.Require(SUPPORTS_REMOVE)
157  public void testRemoveAllIgnoresCount() {
158    initThreeCopies();
159    assertTrue(getMultiset().removeAll(singleton(e0())));
160    assertEmpty(getMultiset());
161  }
162
163  @CollectionSize.Require(SEVERAL)
164  @CollectionFeature.Require(SUPPORTS_REMOVE)
165  public void testRetainAllIgnoresCount() {
166    initThreeCopies();
167    List<E> contents = copyToList(getMultiset());
168    assertFalse(getMultiset().retainAll(singleton(e0())));
169    expectContents(contents);
170  }
171
172  /**
173   * Returns {@link Method} instances for the remove tests that assume multisets support duplicates
174   * so that the test of {@code Multisets.forSet()} can suppress them.
175   */
176  @J2ktIncompatible
177  @GwtIncompatible // reflection
178  public static List<Method> getRemoveDuplicateInitializingMethods() {
179    return asList(getMethod(MultisetRemoveTester.class, "testRemove_some_occurrences_present"));
180  }
181}