001/*
002 * Copyright (C) 2015 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 junit.framework.AssertionFailedError;
030import org.junit.Ignore;
031
032/**
033 * A generic JUnit test which tests {@link Map#computeIfAbsent}. Can't be invoked directly; please
034 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
035 *
036 * @author Louis Wasserman
037 */
038@GwtCompatible
039@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
040public class MapComputeIfAbsentTester<K, V> extends AbstractMapTester<K, V> {
041
042  @MapFeature.Require(SUPPORTS_PUT)
043  public void testComputeIfAbsent_supportedAbsent() {
044    assertEquals(
045        "computeIfAbsent(notPresent, function) should return new value",
046        v3(),
047        getMap()
048            .computeIfAbsent(
049                k3(),
050                k -> {
051                  assertEquals(k3(), k);
052                  return v3();
053                }));
054    expectAdded(e3());
055  }
056
057  @MapFeature.Require(SUPPORTS_PUT)
058  @CollectionSize.Require(absent = ZERO)
059  public void testComputeIfAbsent_supportedPresent() {
060    assertEquals(
061        "computeIfAbsent(present, function) should return existing value",
062        v0(),
063        getMap()
064            .computeIfAbsent(
065                k0(),
066                k -> {
067                  throw new AssertionFailedError();
068                }));
069    expectUnchanged();
070  }
071
072  @MapFeature.Require(SUPPORTS_PUT)
073  public void testComputeIfAbsent_functionReturnsNullNotInserted() {
074    assertNull(
075        "computeIfAbsent(absent, returnsNull) should return null",
076        getMap()
077            .computeIfAbsent(
078                k3(),
079                k -> {
080                  assertEquals(k3(), k);
081                  return null;
082                }));
083    expectUnchanged();
084  }
085
086  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
087  @CollectionSize.Require(absent = ZERO)
088  public void testComputeIfAbsent_nullTreatedAsAbsent() {
089    initMapWithNullValue();
090    assertEquals(
091        "computeIfAbsent(presentAssignedToNull, function) should return newValue",
092        getValueForNullKey(),
093        getMap()
094            .computeIfAbsent(
095                getKeyForNullValue(),
096                k -> {
097                  assertEquals(getKeyForNullValue(), k);
098                  return getValueForNullKey();
099                }));
100    expectReplacement(entry(getKeyForNullValue(), getValueForNullKey()));
101  }
102
103  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS})
104  public void testComputeIfAbsent_nullKeySupported() {
105    getMap()
106        .computeIfAbsent(
107            null,
108            k -> {
109              assertNull(k);
110              return v3();
111            });
112    expectAdded(entry(null, v3()));
113  }
114
115  static class ExpectedException extends RuntimeException {}
116
117  @MapFeature.Require(SUPPORTS_PUT)
118  public void testComputeIfAbsent_functionThrows() {
119    try {
120      getMap()
121          .computeIfAbsent(
122              k3(),
123              k -> {
124                assertEquals(k3(), k);
125                throw new ExpectedException();
126              });
127      fail("Expected ExpectedException");
128    } catch (ExpectedException expected) {
129    }
130    expectUnchanged();
131  }
132
133  @MapFeature.Require(absent = SUPPORTS_PUT)
134  public void testComputeIfAbsent_unsupportedAbsent() {
135    try {
136      getMap()
137          .computeIfAbsent(
138              k3(),
139              k -> {
140                // allowed to be called
141                assertEquals(k3(), k);
142                return v3();
143              });
144      fail("computeIfAbsent(notPresent, function) should throw");
145    } catch (UnsupportedOperationException expected) {
146    }
147    expectUnchanged();
148  }
149
150  @MapFeature.Require(absent = SUPPORTS_PUT)
151  @CollectionSize.Require(absent = ZERO)
152  public void testComputeIfAbsent_unsupportedPresentExistingValue() {
153    try {
154      assertEquals(
155          "computeIfAbsent(present, returnsCurrentValue) should return present or throw",
156          v0(),
157          getMap()
158              .computeIfAbsent(
159                  k0(),
160                  k -> {
161                    assertEquals(k0(), k);
162                    return v0();
163                  }));
164    } catch (UnsupportedOperationException tolerated) {
165    }
166    expectUnchanged();
167  }
168
169  @MapFeature.Require(absent = SUPPORTS_PUT)
170  @CollectionSize.Require(absent = ZERO)
171  public void testComputeIfAbsent_unsupportedPresentDifferentValue() {
172    try {
173      assertEquals(
174          "computeIfAbsent(present, returnsDifferentValue) should return present or throw",
175          v0(),
176          getMap()
177              .computeIfAbsent(
178                  k0(),
179                  k -> {
180                    assertEquals(k0(), k);
181                    return v3();
182                  }));
183    } catch (UnsupportedOperationException tolerated) {
184    }
185    expectUnchanged();
186  }
187
188  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEYS)
189  public void testComputeIfAbsent_nullKeyUnsupported() {
190    try {
191      getMap()
192          .computeIfAbsent(
193              null,
194              k -> {
195                assertNull(k);
196                return v3();
197              });
198      fail("computeIfAbsent(null, function) should throw");
199    } catch (NullPointerException expected) {
200    }
201    expectUnchanged();
202    expectNullKeyMissingWhenNullKeysUnsupported(
203        "Should not contain null key after unsupported computeIfAbsent(null, function)");
204  }
205}