11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2008 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.collect.testing.testers; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.testing.AbstractMapTester; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.testing.features.CollectionSize; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.testing.features.MapFeature; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Collection; 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Map; 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Tests {@link java.util.Map#hashCode}. 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This class is GWT compatible. 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author George van den Driessche 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Chris Povirk 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic class MapHashCodeTester<K, V> extends AbstractMapTester<K, V> { 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testHashCode() { 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int expectedHashCode = 0; 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (Map.Entry<K, V> entry : getSampleEntries()) { 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode += hash(entry); 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals( 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "A Map's hashCode() should be the sum of those of its entries.", 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode, getMap().hashCode()); 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @CollectionSize.Require(absent = CollectionSize.ZERO) 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @MapFeature.Require(ALLOWS_NULL_KEYS) 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testHashCode_containingNullKey() { 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Map.Entry<K, V> entryWithNull = entry(null, samples.e3.getValue()); 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert runEntryWithNullTest(entryWithNull); 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @CollectionSize.Require(absent = CollectionSize.ZERO) 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @MapFeature.Require(ALLOWS_NULL_VALUES) 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testHashCode_containingNullValue() { 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Map.Entry<K, V> entryWithNull = entry(samples.e3.getKey(), null); 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert runEntryWithNullTest(entryWithNull); 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void runEntryWithNullTest(Map.Entry<K, V> entryWithNull) { 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Collection<Map.Entry<K, V>> entries = getSampleEntries(getNumEntries() - 1); 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert entries.add(entryWithNull); 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int expectedHashCode = 0; 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (Map.Entry<K, V> entry : entries) { 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode += hash(entry); 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert resetContainer(getSubjectGenerator().create(entries.toArray())); 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals( 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "A Map's hashCode() should be the sum of those of its entries (where " 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert + "a null element in an entry counts as having a hash of zero).", 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode, getMap().hashCode()); 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static int hash(Map.Entry<?, ?> e) { 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return (e.getKey() == null ? 0 : e.getKey().hashCode()) 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert ^ (e.getValue() == null ? 0 : e.getValue().hashCode()); 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 84