001 /* 002 * Created on Jul 15, 2010 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with 005 * the License. You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on 010 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the 011 * specific language governing permissions and limitations under the License. 012 * 013 * Copyright @2010-2011 the original author or authors. 014 */ 015 package org.fest.assertions.core; 016 017 import java.util.*; 018 019 /** 020 * Base contract of all assertion objects: the minimum functionality that any assertion object should provide. 021 * @param <S> the "self" type of this assertion class. Please read "<a href="http://bit.ly/anMa4g" 022 * target="_blank">Emulating 'self types' using Java Generics to simplify fluent API implementation</a>" 023 * for more details. 024 * @param <A> the type of the "actual" value. 025 * 026 * @author Yvonne Wang 027 * @author Alex Ruiz 028 */ 029 public interface Assert<S, A> extends Descriptable<S>, ExtensionPoints<S, A> { 030 031 /** 032 * Verifies that the actual value is equal to the given one. 033 * @param expected the given value to compare the actual value to. 034 * @return {@code this} assertion object. 035 * @throws AssertionError if the actual value is not equal to the given one. 036 */ 037 S isEqualTo(A expected); 038 039 /** 040 * Verifies that the actual value is not equal to the given one. 041 * @param other the given value to compare the actual value to. 042 * @return {@code this} assertion object. 043 * @throws AssertionError if the actual value is equal to the given one. 044 */ 045 S isNotEqualTo(A other); 046 047 /** 048 * Verifies that the actual value is {@code null}. 049 * @throws AssertionError if the actual value is not {@code null}. 050 */ 051 void isNull(); 052 053 /** 054 * Verifies that the actual value is not {@code null}. 055 * @return {@code this} assertion object. 056 * @throws AssertionError if the actual value is {@code null}. 057 */ 058 S isNotNull(); 059 060 /** 061 * Verifies that the actual value is the same as the given one. 062 * @param expected the given value to compare the actual value to. 063 * @return {@code this} assertion object. 064 * @throws AssertionError if the actual value is not the same as the given one. 065 */ 066 S isSameAs(A expected); 067 068 /** 069 * Verifies that the actual value is not the same as the given one. 070 * @param other the given value to compare the actual value to. 071 * @return {@code this} assertion object. 072 * @throws AssertionError if the actual value is the same as the given one. 073 */ 074 S isNotSameAs(A other); 075 076 /** 077 * Verifies that the actual value is present in the given array of values. 078 * @param values the given array to search the actual value in. 079 * @return {@code this} assertion object. 080 * @throws NullPointerException if the given array is {@code null}. 081 * @throws IllegalArgumentException if the given array is empty. 082 * @throws AssertionError if the actual value is not present in the given array. 083 */ 084 S isIn(A... values); 085 086 /** 087 * Verifies that the actual value is not present in the given array of values. 088 * @param values the given array to search the actual value in. 089 * @return {@code this} assertion object. 090 * @throws NullPointerException if the given array is {@code null}. 091 * @throws IllegalArgumentException if the given array is empty. 092 * @throws AssertionError if the actual value is present in the given array. 093 */ 094 S isNotIn(A... values); 095 096 /** 097 * Verifies that the actual value is present in the given collection of values. 098 * @param values the given collection to search the actual value in. 099 * @return {@code this} assertion object. 100 * @throws NullPointerException if the given collection is {@code null}. 101 * @throws IllegalArgumentException if the given collection is empty. 102 * @throws AssertionError if the actual value is not present in the given collection. 103 */ 104 S isIn(Collection<?> values); 105 106 /** 107 * Verifies that the actual value is not present in the given collection of values. 108 * @param values the given collection to search the actual value in. 109 * @return {@code this} assertion object. 110 * @throws NullPointerException if the given collection is {@code null}. 111 * @throws IllegalArgumentException if the given collection is empty. 112 * @throws AssertionError if the actual value is present in the given collection. 113 */ 114 S isNotIn(Collection<?> values); 115 116 /** 117 * Use given custom comparator instead of relying on actual type A equals method for incoming assertion checks.<br> 118 * Custom comparator is bound to assertion instance, meaning that if a new assertion is created, it will use default 119 * comparison strategy. </p> Example : 120 * 121 * <pre> 122 * // compares invoices by payee 123 * assertThat(invoiceList).usingComparator(invoicePayeeComparator).isEqualTo(expectedInvoiceList). 124 * 125 * // compares invoices by date, doesNotHaveDuplicates and contains both use the given invoice date comparator 126 * assertThat(invoiceList).usingComparator(invoiceDateComparator).doesNotHaveDuplicates().contains(may2010Invoice) 127 * 128 * // as assertThat(invoiceList) creates a new assertion, it uses standard comparison strategy (Invoice's equal method) to compare invoiceList elements to lowestInvoice. 129 * assertThat(invoiceList).contains(lowestInvoice). 130 * </pre> 131 * 132 * Custom comparator is not parameterized with actual type A (ie. Comparator<A>) because if it was, we could not 133 * write the following code : 134 * 135 * <pre> 136 * // frodo and sam are instances of Character (a Character having a Race) 137 * // raceComparator implements Comparator<Character> 138 * // assertThat(frodo) returns an ObjectAssert and not a custom CharacterAssert implementing Assert<CharacterAssert, Character> 139 * assertThat(frodo).usingComparator(raceComparator).isEqualTo(sam); // won't compile ! 140 * 141 * The code does not compile because assertThat(frodo) returns an ObjectAssert, thus usingComparator expects a Comparator<Object> 142 * and Comparator<Character> is not a Comparator<Object> as generics are not reified. 143 * 144 * Note that, it would have worked if assertThat(frodo) returned a CharacterAssert implementing Assert<CharacterAssert, Character>. 145 * </pre> 146 * 147 * @param customComparator the comparator to use for incoming assertion checks. 148 * @throws NullPointerException if the given comparator is {@code null}. 149 * @return {@code this} assertion object. 150 */ 151 S usingComparator(Comparator<?> customComparator); 152 153 /** 154 * Revert to standard comparison for incoming assertion checks.<br> 155 * This method should be used to disable a custom comparison strategy set by calling 156 * {@link #usingComparator(Comparator)}. 157 * @return {@code this} assertion object. 158 */ 159 S usingDefaultComparator(); 160 161 /** 162 * Throws <code>{@link UnsupportedOperationException}</code> if called. It is easy to accidentally call 163 * <code>{@link #equals(Object)}</code> instead of <code>isEqualTo</code>. 164 * @throws UnsupportedOperationException if this method is called. 165 */ 166 @Override boolean equals(Object obj); 167 }