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 com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE; 024 025import com.google.common.annotations.GwtCompatible; 026import com.google.common.annotations.GwtIncompatible; 027import com.google.common.collect.testing.AbstractMapTester; 028import com.google.common.collect.testing.Helpers; 029import com.google.common.collect.testing.features.CollectionSize; 030import com.google.common.collect.testing.features.MapFeature; 031import java.lang.reflect.Method; 032import java.util.Map; 033import junit.framework.AssertionFailedError; 034import org.junit.Ignore; 035 036/** 037 * A generic JUnit test which tests {@link Map#merge}. Can't be invoked directly; please see {@link 038 * com.google.common.collect.testing.MapTestSuiteBuilder}. 039 * 040 * @author Louis Wasserman 041 */ 042@GwtCompatible(emulated = true) 043@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests. 044public class MapMergeTester<K, V> extends AbstractMapTester<K, V> { 045 @MapFeature.Require(SUPPORTS_PUT) 046 public void testAbsent() { 047 assertEquals( 048 "Map.merge(absent, value, function) should return value", 049 v3(), 050 getMap() 051 .merge( 052 k3(), 053 v3(), 054 (oldV, newV) -> { 055 throw new AssertionFailedError( 056 "Should not call merge function if key was absent"); 057 })); 058 expectAdded(e3()); 059 } 060 061 @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES}) 062 @CollectionSize.Require(absent = ZERO) 063 public void testMappedToNull() { 064 initMapWithNullValue(); 065 assertEquals( 066 "Map.merge(keyMappedToNull, value, function) should return value", 067 v3(), 068 getMap() 069 .merge( 070 getKeyForNullValue(), 071 v3(), 072 (oldV, newV) -> { 073 throw new AssertionFailedError( 074 "Should not call merge function if key was mapped to null"); 075 })); 076 expectReplacement(entry(getKeyForNullValue(), v3())); 077 } 078 079 @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS}) 080 public void testMergeAbsentNullKey() { 081 assertEquals( 082 "Map.merge(null, value, function) should return value", 083 v3(), 084 getMap() 085 .merge( 086 null, 087 v3(), 088 (oldV, newV) -> { 089 throw new AssertionFailedError( 090 "Should not call merge function if key was absent"); 091 })); 092 expectAdded(entry(null, v3())); 093 } 094 095 @MapFeature.Require(SUPPORTS_PUT) 096 @CollectionSize.Require(absent = ZERO) 097 public void testMergePresent() { 098 assertEquals( 099 "Map.merge(present, value, function) should return function result", 100 v4(), 101 getMap() 102 .merge( 103 k0(), 104 v3(), 105 (oldV, newV) -> { 106 assertEquals(v0(), oldV); 107 assertEquals(v3(), newV); 108 return v4(); 109 })); 110 expectReplacement(entry(k0(), v4())); 111 } 112 113 private static class ExpectedException extends RuntimeException {} 114 115 @MapFeature.Require(SUPPORTS_PUT) 116 @CollectionSize.Require(absent = ZERO) 117 public void testMergeFunctionThrows() { 118 try { 119 getMap() 120 .merge( 121 k0(), 122 v3(), 123 (oldV, newV) -> { 124 assertEquals(v0(), oldV); 125 assertEquals(v3(), newV); 126 throw new ExpectedException(); 127 }); 128 fail("Expected ExpectedException"); 129 } catch (ExpectedException expected) { 130 } 131 expectUnchanged(); 132 } 133 134 @MapFeature.Require(SUPPORTS_REMOVE) 135 @CollectionSize.Require(absent = ZERO) 136 public void testMergePresentToNull() { 137 assertNull( 138 "Map.merge(present, value, functionReturningNull) should return null", 139 getMap() 140 .merge( 141 k0(), 142 v3(), 143 (oldV, newV) -> { 144 assertEquals(v0(), oldV); 145 assertEquals(v3(), newV); 146 return null; 147 })); 148 expectMissing(e0()); 149 } 150 151 public void testMergeNullValue() { 152 try { 153 getMap() 154 .merge( 155 k0(), 156 null, 157 (oldV, newV) -> { 158 throw new AssertionFailedError("Should not call merge function if value was null"); 159 }); 160 fail("Expected NullPointerException or UnsupportedOperationException"); 161 } catch (NullPointerException | UnsupportedOperationException expected) { 162 } 163 } 164 165 public void testMergeNullFunction() { 166 try { 167 getMap().merge(k0(), v3(), null); 168 fail("Expected NullPointerException or UnsupportedOperationException"); 169 } catch (NullPointerException | UnsupportedOperationException expected) { 170 } 171 } 172 173 @MapFeature.Require(absent = SUPPORTS_PUT) 174 public void testMergeUnsupported() { 175 try { 176 getMap() 177 .merge( 178 k3(), 179 v3(), 180 (oldV, newV) -> { 181 throw new AssertionFailedError(); 182 }); 183 fail("Expected UnsupportedOperationException"); 184 } catch (UnsupportedOperationException expected) { 185 } 186 } 187 188 /** 189 * Returns the {@link Method} instance for {@link #testMergeNullValue()} so that tests of {@link 190 * Hashtable} can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()}. 191 */ 192 @GwtIncompatible // reflection 193 public static Method getMergeNullValueMethod() { 194 return Helpers.getMethod(MapMergeTester.class, "testMergeNullValue"); 195 } 196}