001/*
002 * Copyright (C) 2016 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.testers;
018
019import static com.google.common.collect.testing.features.CollectionSize.ZERO;
020import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
021import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;
022import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;
023import static org.junit.Assert.assertThrows;
024
025import com.google.common.annotations.GwtCompatible;
026import com.google.common.collect.testing.AbstractMapTester;
027import com.google.common.collect.testing.features.CollectionSize;
028import com.google.common.collect.testing.features.MapFeature;
029import com.google.common.collect.testing.testers.TestExceptions.SomeUncheckedException;
030import java.util.Map;
031import java.util.Map.Entry;
032import junit.framework.AssertionFailedError;
033
034/**
035 * A generic JUnit test which tests {@link Map#computeIfPresent}. Can't be invoked directly; please
036 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
037 *
038 * @author Louis Wasserman
039 */
040@GwtCompatible
041public class MapComputeIfPresentTester<K, V> extends AbstractMapTester<K, V> {
042
043  @MapFeature.Require(SUPPORTS_PUT)
044  public void testComputeIfPresent_supportedAbsent() {
045    assertNull(
046        "computeIfPresent(notPresent, function) should return null",
047        getMap()
048            .computeIfPresent(
049                k3(),
050                (k, v) -> {
051                  throw new AssertionFailedError();
052                }));
053    expectUnchanged();
054  }
055
056  @MapFeature.Require(SUPPORTS_PUT)
057  @CollectionSize.Require(absent = ZERO)
058  public void testComputeIfPresent_supportedPresent() {
059    assertEquals(
060        "computeIfPresent(present, function) should return new value",
061        v3(),
062        getMap()
063            .computeIfPresent(
064                k0(),
065                (k, v) -> {
066                  assertEquals(k0(), k);
067                  assertEquals(v0(), v);
068                  return v3();
069                }));
070    expectReplacement(entry(k0(), v3()));
071  }
072
073  @MapFeature.Require(SUPPORTS_PUT)
074  @CollectionSize.Require(absent = ZERO)
075  public void testComputeIfPresent_functionReturnsNull() {
076    assertNull(
077        "computeIfPresent(present, returnsNull) should return null",
078        getMap()
079            .computeIfPresent(
080                k0(),
081                (k, v) -> {
082                  assertEquals(k0(), k);
083                  assertEquals(v0(), v);
084                  return null;
085                }));
086    expectMissing(e0());
087  }
088
089  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
090  @CollectionSize.Require(absent = ZERO)
091  public void testComputeIfPresent_nullTreatedAsAbsent() {
092    initMapWithNullValue();
093    assertNull(
094        "computeIfPresent(presentAssignedToNull, function) should return null",
095        getMap()
096            .computeIfPresent(
097                getKeyForNullValue(),
098                (k, v) -> {
099                  throw new AssertionFailedError();
100                }));
101    expectReplacement(entry(getKeyForNullValue(), null));
102  }
103
104  @MapFeature.Require(SUPPORTS_PUT)
105  @CollectionSize.Require(absent = ZERO)
106  public void testComputeIfPresent_functionThrows() {
107    assertThrows(
108        SomeUncheckedException.class,
109        () ->
110            getMap()
111                .computeIfPresent(
112                    k0(),
113                    (k, v) -> {
114                      assertEquals(k0(), k);
115                      assertEquals(v0(), v);
116                      throw new SomeUncheckedException();
117                    }));
118    expectUnchanged();
119  }
120
121  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
122  @CollectionSize.Require(absent = ZERO)
123  public void testComputeIfPresent_nullKeySupportedPresent() {
124    initMapWithNullKey();
125    assertEquals(
126        "computeIfPresent(null, function) should return new value",
127        v3(),
128        getMap()
129            .computeIfPresent(
130                null,
131                (k, v) -> {
132                  assertNull(k);
133                  assertEquals(getValueForNullKey(), v);
134                  return v3();
135                }));
136
137    Entry<K, V>[] expected = createArrayWithNullKey();
138    expected[getNullLocation()] = entry(null, v3());
139    expectContents(expected);
140  }
141
142  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
143  public void testComputeIfPresent_nullKeySupportedAbsent() {
144    assertNull(
145        "computeIfPresent(null, function) should return null",
146        getMap()
147            .computeIfPresent(
148                null,
149                (k, v) -> {
150                  throw new AssertionFailedError();
151                }));
152    expectUnchanged();
153  }
154
155  @MapFeature.Require(absent = SUPPORTS_PUT)
156  public void testComputeIfPresent_unsupportedAbsent() {
157    try {
158      getMap()
159          .computeIfPresent(
160              k3(),
161              (k, v) -> {
162                throw new AssertionFailedError();
163              });
164    } catch (UnsupportedOperationException tolerated) {
165    }
166    expectUnchanged();
167  }
168
169  @MapFeature.Require(absent = SUPPORTS_PUT)
170  @CollectionSize.Require(absent = ZERO)
171  public void testComputeIfPresent_unsupportedPresent() {
172    assertThrows(
173        UnsupportedOperationException.class, () -> getMap().computeIfPresent(k0(), (k, v) -> v3()));
174    expectUnchanged();
175  }
176}