| 1 | /* |
| 2 | * JTiger Unit Testing Framework for J2SE 1.5 |
| 3 | * Copyright (C) 2005 Tony Morris |
| 4 | * |
| 5 | * This software is licenced under the |
| 6 | * Common Public Licence version 1.0 |
| 7 | * http://www.opensource.org/licenses/cpl1.0.php |
| 8 | * |
| 9 | * You received a copy of this licence with this software. |
| 10 | */ |
| 11 | package org.jtiger.assertion; |
| 12 | |
| 13 | final class EqualsMethodContractTesterFactory |
| 14 | { |
| 15 | private EqualsMethodContractTesterFactory() |
| 16 | { |
| 17 | |
| 18 | } |
| 19 | |
| 20 | static EqualsMethodContractTester newEqualsMethodContractTester(final ObjectFactory<?> factory) throws NullPointerException |
| 21 | { |
| 22 | if(factory == null) |
| 23 | { |
| 24 | throw new NullPointerException(); |
| 25 | } |
| 26 | |
| 27 | return new EqualsMethodContractTesterImpl(factory); |
| 28 | } |
| 29 | |
| 30 | private static final class EqualsMethodContractTesterImpl implements EqualsMethodContractTester |
| 31 | { |
| 32 | private final ObjectFactory<?> factory; |
| 33 | |
| 34 | EqualsMethodContractTesterImpl(final ObjectFactory<?> factory) |
| 35 | { |
| 36 | this.factory = factory; |
| 37 | } |
| 38 | |
| 39 | public boolean isUnequalToNull() |
| 40 | { |
| 41 | final Object x = factory.newInstanceX(); |
| 42 | final Object y = factory.newInstanceY(); |
| 43 | |
| 44 | return x != null && !x.equals(null) && y != null && !y.equals(null); |
| 45 | } |
| 46 | |
| 47 | public boolean isConsistentAcrossInvocations() |
| 48 | { |
| 49 | for (int i = 0; i < 20; ++i) |
| 50 | { |
| 51 | if(!isUnequalToNull()) |
| 52 | { |
| 53 | return false; |
| 54 | } |
| 55 | |
| 56 | if(!isReflexive()) |
| 57 | { |
| 58 | return false; |
| 59 | } |
| 60 | |
| 61 | if(!isSymmetric()) |
| 62 | { |
| 63 | return false; |
| 64 | } |
| 65 | |
| 66 | if(!isTransitive()) |
| 67 | { |
| 68 | return false; |
| 69 | } |
| 70 | |
| 71 | if(!isUnequalToUnequalInstance()) |
| 72 | { |
| 73 | return false; |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | return true; |
| 78 | } |
| 79 | |
| 80 | public boolean isReflexive() |
| 81 | { |
| 82 | final Object x = factory.newInstanceX(); |
| 83 | final Object y = factory.newInstanceY(); |
| 84 | |
| 85 | return x.equals(x) && y.equals(y); |
| 86 | } |
| 87 | |
| 88 | public boolean isSymmetric() |
| 89 | { |
| 90 | final Object x1 = factory.newInstanceX(); |
| 91 | final Object x2 = factory.newInstanceX(); |
| 92 | final Object y1 = factory.newInstanceY(); |
| 93 | final Object y2 = factory.newInstanceY(); |
| 94 | |
| 95 | return x1.equals(x2) && x2.equals(x1) && y1.equals(y2) && y2.equals(y1); |
| 96 | } |
| 97 | |
| 98 | public boolean isTransitive() |
| 99 | { |
| 100 | final Object x1 = factory.newInstanceX(); |
| 101 | final Object x2 = factory.newInstanceX(); |
| 102 | final Object x3 = factory.newInstanceX(); |
| 103 | final Object y1 = factory.newInstanceY(); |
| 104 | final Object y2 = factory.newInstanceY(); |
| 105 | final Object y3 = factory.newInstanceY(); |
| 106 | |
| 107 | return x1.equals(x2) && x2.equals(x3) && x1.equals(x3) && |
| 108 | y1.equals(y2) && y2.equals(y3) && y1.equals(y3); |
| 109 | } |
| 110 | |
| 111 | public boolean isUnequalToUnequalInstance() |
| 112 | { |
| 113 | final Object x = factory.newInstanceX(); |
| 114 | final Object y = factory.newInstanceY(); |
| 115 | |
| 116 | return !x.equals(y) && !y.equals(x); |
| 117 | } |
| 118 | |
| 119 | public boolean isUnequalToArbitraryType() |
| 120 | { |
| 121 | final Object x = factory.newInstanceX(); |
| 122 | final Object y = factory.newInstanceY(); |
| 123 | |
| 124 | final class ArbitraryType |
| 125 | { |
| 126 | private ArbitraryType() |
| 127 | { |
| 128 | |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | return !x.equals(new ArbitraryType()) && !y.equals(new ArbitraryType()); |
| 133 | } |
| 134 | |
| 135 | public boolean fillsContract() |
| 136 | { |
| 137 | return (isUnequalToNull() |
| 138 | && isConsistentAcrossInvocations() |
| 139 | && isReflexive() |
| 140 | && isSymmetric() |
| 141 | && isTransitive() |
| 142 | && isUnequalToArbitraryType() |
| 143 | && isUnequalToUnequalInstance()); |
| 144 | } |
| 145 | } |
| 146 | } |