11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2007 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.testing; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.base.Preconditions.checkNotNull; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static junit.framework.Assert.assertEquals; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static junit.framework.Assert.assertTrue; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.GwtCompatible; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.base.Objects; 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.ImmutableList; 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.Iterables; 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.Lists; 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.testing.RelationshipTester.RelationshipAssertion; 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.List; 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Tester for equals() and hashCode() methods of a class. 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>To use, create a new EqualsTester and add equality groups where each group 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * contains objects that are supposed to be equal to each other, and objects of 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * different groups are expected to be unequal. For example: 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <pre> 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * new EqualsTester() 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * .addEqualityGroup("hello", "h" + "ello") 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * .addEqualityGroup("world", "wor" + "ld") 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * .addEqualityGroup(2, 1 + 1) 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * .testEquals(); 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * </pre> 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * This tests: 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <ul> 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>comparing each object against itself returns true 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>comparing each object against null returns false 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>comparing each object an instance of an incompatible class returns false 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>comparing each pair of objects within the same equality group returns 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * true 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>comparing each pair of objects from different equality groups returns 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * false 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>the hash code of any two equal objects are equal 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * </ul> 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>When a test fails, the error message labels the objects involved in 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the failed comparison as follows: 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <ul> 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <li>"{@code [group }<i>i</i>{@code , item }<i>j</i>{@code ]}" refers to the 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <i>j</i><sup>th</sup> item in the <i>i</i><sup>th</sup> equality group, 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * where both equality groups and the items within equality groups are 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * numbered starting from 1. When either a constructor argument or an 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * equal object is provided, that becomes group 1. 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * </ul> 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Jim McMaster 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Jige Yu 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@Beta 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@GwtCompatible 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic final class EqualsTester { 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static final int REPETITIONS = 3; 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final List<List<Object>> equalityGroups = Lists.newArrayList(); 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Constructs an empty EqualsTester instance 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public EqualsTester() {} 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Adds {@code equalityGroup} with objects that are supposed to be equal to 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * each other and not equal to any other equality groups added to this tester. 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public EqualsTester addEqualityGroup(Object... equalityGroup) { 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotNull(equalityGroup); 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert equalityGroups.add(ImmutableList.copyOf(equalityGroup)); 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Run tests on equals method, throwing a failure on an invalid test 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public EqualsTester testEquals() { 981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert RelationshipTester<Object> delegate = new RelationshipTester<Object>( 991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert new RelationshipAssertion<Object>() { 1001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public void assertRelated(Object item, Object related) { 1011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals("$ITEM must be equal to $RELATED", item, related); 1021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int itemHash = item.hashCode(); 1031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert int relatedHash = related.hashCode(); 1041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals("the hash (" + itemHash + ") of $ITEM must be equal to the hash (" 1051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert + relatedHash +") of $RELATED", itemHash, relatedHash); 1061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public void assertUnrelated(Object item, Object unrelated) { 1091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // TODO(cpovirk): should this implementation (and 1101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // RelationshipAssertions in general) accept null inputs? 1111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue("$ITEM must be unequal to $UNRELATED", !Objects.equal(item, unrelated)); 1121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }); 1141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (List<Object> group : equalityGroups) { 1151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert delegate.addRelatedGroup(group); 1161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (int run = 0; run < REPETITIONS; run++) { 1181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert testItems(); 1191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert delegate.test(); 1201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void testItems() { 1251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (Object item : Iterables.concat(equalityGroups)) { 1261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(item + " must be unequal to null", !item.equals(null)); 1271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(item + " must be unequal to an arbitrary object of another class", 1281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert !item.equals(NotAnInstance.EQUAL_TO_NOTHING)); 1291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(item + " must be equal to itself", item, item); 1301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals("the hash of " + item + " must be consistent", item.hashCode(), item.hashCode()); 1311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 1351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Class used to test whether equals() correctly handles an instance 1361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * of an incompatible class. Since it is a private inner class, the 1371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * invoker can never pass in an instance to the tester 1381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 1391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private enum NotAnInstance { 1401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert EQUAL_TO_NOTHING; 1411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 143