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;
023
024import com.google.common.annotations.GwtCompatible;
025import com.google.common.collect.testing.AbstractMapTester;
026import com.google.common.collect.testing.features.CollectionSize;
027import com.google.common.collect.testing.features.MapFeature;
028import java.util.Map;
029import java.util.Map.Entry;
030import junit.framework.AssertionFailedError;
031import org.junit.Ignore;
032
033/**
034 * A generic JUnit test which tests {@link Map#computeIfPresent}. Can't be invoked directly; please
035 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
036 *
037 * @author Louis Wasserman
038 */
039@GwtCompatible
040@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
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  static class ExpectedException extends RuntimeException {}
105
106  @MapFeature.Require(SUPPORTS_PUT)
107  @CollectionSize.Require(absent = ZERO)
108  public void testComputeIfPresent_functionThrows() {
109    try {
110      getMap()
111          .computeIfPresent(
112              k0(),
113              (k, v) -> {
114                assertEquals(k0(), k);
115                assertEquals(v0(), v);
116                throw new ExpectedException();
117              });
118      fail("Expected ExpectedException");
119    } catch (ExpectedException expected) {
120    }
121    expectUnchanged();
122  }
123
124  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
125  @CollectionSize.Require(absent = ZERO)
126  public void testComputeIfPresent_nullKeySupportedPresent() {
127    initMapWithNullKey();
128    assertEquals(
129        "computeIfPresent(null, function) should return new value",
130        v3(),
131        getMap()
132            .computeIfPresent(
133                null,
134                (k, v) -> {
135                  assertNull(k);
136                  assertEquals(getValueForNullKey(), v);
137                  return v3();
138                }));
139
140    Entry<K, V>[] expected = createArrayWithNullKey();
141    expected[getNullLocation()] = entry(null, v3());
142    expectContents(expected);
143  }
144
145  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
146  public void testComputeIfPresent_nullKeySupportedAbsent() {
147    assertNull(
148        "computeIfPresent(null, function) should return null",
149        getMap()
150            .computeIfPresent(
151                null,
152                (k, v) -> {
153                  throw new AssertionFailedError();
154                }));
155    expectUnchanged();
156  }
157
158  @MapFeature.Require(absent = SUPPORTS_PUT)
159  public void testComputeIfPresent_unsupportedAbsent() {
160    try {
161      getMap()
162          .computeIfPresent(
163              k3(),
164              (k, v) -> {
165                throw new AssertionFailedError();
166              });
167    } catch (UnsupportedOperationException tolerated) {
168    }
169    expectUnchanged();
170  }
171
172  @MapFeature.Require(absent = SUPPORTS_PUT)
173  @CollectionSize.Require(absent = ZERO)
174  public void testComputeIfPresent_unsupportedPresent() {
175    try {
176      getMap().computeIfPresent(k0(), (k, v) -> v3());
177      fail("Expected UnsupportedOperationException");
178    } catch (UnsupportedOperationException expected) {
179    }
180    expectUnchanged();
181  }
182}