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.Helpers.getMethod; 020import static com.google.common.collect.testing.features.CollectionSize.ZERO; 021import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS; 022import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES; 023import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT; 024import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE; 025import static com.google.common.collect.testing.testers.ReflectionFreeAssertThrows.assertThrows; 026 027import com.google.common.annotations.GwtCompatible; 028import com.google.common.annotations.GwtIncompatible; 029import com.google.common.annotations.J2ktIncompatible; 030import com.google.common.collect.testing.AbstractMapTester; 031import com.google.common.collect.testing.features.CollectionSize; 032import com.google.common.collect.testing.features.MapFeature; 033import com.google.common.collect.testing.testers.TestExceptions.SomeUncheckedException; 034import java.lang.reflect.Method; 035import java.util.Hashtable; 036import java.util.Map; 037import junit.framework.AssertionFailedError; 038import org.junit.Ignore; 039 040/** 041 * A generic JUnit test which tests {@link Map#merge}. Can't be invoked directly; please see {@link 042 * com.google.common.collect.testing.MapTestSuiteBuilder}. 043 * 044 * @author Louis Wasserman 045 */ 046@GwtCompatible(emulated = true) 047@Ignore("test runners must not instantiate and run this directly, only via suites we build") 048// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests. 049@SuppressWarnings("JUnit4ClassUsedInJUnit3") 050public class MapMergeTester<K, V> extends AbstractMapTester<K, V> { 051 @MapFeature.Require(SUPPORTS_PUT) 052 public void testAbsent() { 053 assertEquals( 054 "Map.merge(absent, value, function) should return value", 055 v3(), 056 getMap() 057 .merge( 058 k3(), 059 v3(), 060 (oldV, newV) -> { 061 throw new AssertionFailedError( 062 "Should not call merge function if key was absent"); 063 })); 064 expectAdded(e3()); 065 } 066 067 @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES}) 068 @CollectionSize.Require(absent = ZERO) 069 public void testMappedToNull() { 070 initMapWithNullValue(); 071 assertEquals( 072 "Map.merge(keyMappedToNull, value, function) should return value", 073 v3(), 074 getMap() 075 .merge( 076 getKeyForNullValue(), 077 v3(), 078 (oldV, newV) -> { 079 throw new AssertionFailedError( 080 "Should not call merge function if key was mapped to null"); 081 })); 082 expectReplacement(entry(getKeyForNullValue(), v3())); 083 } 084 085 @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_KEYS}) 086 public void testMergeAbsentNullKey() { 087 assertEquals( 088 "Map.merge(null, value, function) should return value", 089 v3(), 090 getMap() 091 .merge( 092 null, 093 v3(), 094 (oldV, newV) -> { 095 throw new AssertionFailedError( 096 "Should not call merge function if key was absent"); 097 })); 098 expectAdded(entry(null, v3())); 099 } 100 101 @MapFeature.Require(SUPPORTS_PUT) 102 @CollectionSize.Require(absent = ZERO) 103 public void testMergePresent() { 104 assertEquals( 105 "Map.merge(present, value, function) should return function result", 106 v4(), 107 getMap() 108 .merge( 109 k0(), 110 v3(), 111 (oldV, newV) -> { 112 assertEquals(v0(), oldV); 113 assertEquals(v3(), newV); 114 return v4(); 115 })); 116 expectReplacement(entry(k0(), v4())); 117 } 118 119 @MapFeature.Require(SUPPORTS_PUT) 120 @CollectionSize.Require(absent = ZERO) 121 public void testMergeFunctionThrows() { 122 assertThrows( 123 SomeUncheckedException.class, 124 () -> 125 getMap() 126 .merge( 127 k0(), 128 v3(), 129 (oldV, newV) -> { 130 assertEquals(v0(), oldV); 131 assertEquals(v3(), newV); 132 throw new SomeUncheckedException(); 133 })); 134 expectUnchanged(); 135 } 136 137 @MapFeature.Require(SUPPORTS_REMOVE) 138 @CollectionSize.Require(absent = ZERO) 139 public void testMergePresentToNull() { 140 assertNull( 141 "Map.merge(present, value, functionReturningNull) should return null", 142 getMap() 143 .merge( 144 k0(), 145 v3(), 146 (oldV, newV) -> { 147 assertEquals(v0(), oldV); 148 assertEquals(v3(), newV); 149 return null; 150 })); 151 expectMissing(e0()); 152 } 153 154 public void testMergeNullValue() { 155 try { 156 getMap() 157 .merge( 158 k0(), 159 null, 160 (oldV, newV) -> { 161 throw new AssertionFailedError("Should not call merge function if value was null"); 162 }); 163 fail("Expected NullPointerException or UnsupportedOperationException"); 164 } catch (NullPointerException | UnsupportedOperationException expected) { 165 } 166 } 167 168 public void testMergeNullFunction() { 169 try { 170 getMap().merge(k0(), v3(), null); 171 fail("Expected NullPointerException or UnsupportedOperationException"); 172 } catch (NullPointerException | UnsupportedOperationException expected) { 173 } 174 } 175 176 @MapFeature.Require(absent = SUPPORTS_PUT) 177 public void testMergeUnsupported() { 178 assertThrows( 179 UnsupportedOperationException.class, 180 () -> 181 getMap() 182 .merge( 183 k3(), 184 v3(), 185 (oldV, newV) -> { 186 throw new AssertionFailedError(); 187 })); 188 } 189 190 /** 191 * Returns the {@link Method} instance for {@link #testMergeNullValue()} so that tests of {@link 192 * Hashtable} can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()}. 193 */ 194 @J2ktIncompatible 195 @GwtIncompatible // reflection 196 public static Method getMergeNullValueMethod() { 197 return getMethod(MapMergeTester.class, "testMergeNullValue"); 198 } 199}