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.CollectionFeature.ALLOWS_NULL_VALUES; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.testing.features.CollectionFeature; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.testing.features.CollectionSize; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.lang.reflect.Method; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Collection; 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Tests {@link java.util.Set#hashCode}. 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>This class is GWT compatible. 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author George van den Driessche 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic class SetHashCodeTester<E> extends AbstractSetTester<E> { 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testHashCode() { 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int expectedHashCode = 0; 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (E element : getSampleElements()) { 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode += ((element == null) ? 0 : element.hashCode()); 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals( 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "A Set's hashCode() should be the sum of those of its elements.", 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode, getSet().hashCode()); 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @CollectionSize.Require(absent = CollectionSize.ZERO) 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @CollectionFeature.Require(ALLOWS_NULL_VALUES) 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testHashCode_containingNull() { 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Collection<E> elements = getSampleElements(getNumElements() - 1); 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int expectedHashCode = 0; 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (E element : elements) { 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode += ((element == null) ? 0 : element.hashCode()); 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert elements.add(null); 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert collection = getSubjectGenerator().create(elements.toArray()); 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals( 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "A Set's hashCode() should be the sum of those of its elements (with " 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert + "a null element counting as having a hash of zero).", 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert expectedHashCode, getSet().hashCode()); 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns the {@link Method} instances for the test methods in this class 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * which call {@code hashCode()} on the set values so that set tests on 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * unhashable objects can suppress it with 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code FeatureSpecificTestSuiteBuilder.suppressing()}. 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public static Method[] getHashCodeMethods() { 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return new Method[]{ 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Platform.getMethod(SetHashCodeTester.class, "testHashCode"), 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Platform.getMethod(SetHashCodeTester.class, "testHashCode_containingNull") }; 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 74