001 /*
002 * Created on Jul 25, 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.Comparator;
018
019 /**
020 * Assertions applicable to groups of values that can be enumerated (e.g. arrays, collections or strings.)
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 <T> the type of elements of the "actual" value.
025 *
026 * @author Yvonne Wang
027 * @author Alex Ruiz
028 * @author Mikhail Mazursky
029 */
030 public interface EnumerableAssert<S extends EnumerableAssert<S, T>, T> {
031
032 /**
033 * Verifies that the actual group of values is {@code null} or empty.
034 * @throws AssertionError if the actual group of values is not {@code null} or not empty.
035 */
036 void isNullOrEmpty();
037
038 /**
039 * Verifies that the actual group of values is empty.
040 * @throws AssertionError if the actual group of values is not empty.
041 */
042 void isEmpty();
043
044 /**
045 * Verifies that the actual group of values is not empty.
046 * @return {@code this} assertion object.
047 * @throws AssertionError if the actual group of values is empty.
048 */
049 S isNotEmpty();
050
051 /**
052 * Verifies that the number of values in the actual group is equal to the given one.
053 * @param expected the expected number of values in the actual group.
054 * @return {@code this} assertion object.
055 * @throws AssertionError if the number of values of the actual group is not equal to the given one.
056 */
057 S hasSize(int expected);
058
059 /**
060 * Use given custom comparator instead of relying on actual type A <code>equals</code> method to compare group
061 * elements for incoming assertion checks.
062 * <p>
063 * Custom comparator is bound to assertion instance, meaning that if a new assertion is created, it will use default
064 * comparison strategy.
065 * <p>
066 * Examples :
067 *
068 * <pre>
069 * // compares invoices by payee
070 * assertThat(invoiceList).usingComparator(invoicePayeeComparator).isEqualTo(expectedInvoiceList).
071 *
072 * // compares invoices by date, doesNotHaveDuplicates and contains both use the given invoice date comparator
073 * assertThat(invoiceList).usingComparator(invoiceDateComparator).doesNotHaveDuplicates().contains(may2010Invoice)
074 *
075 * // as assertThat(invoiceList) creates a new assertion, it falls back to standard comparison strategy
076 * // based on Invoice's equal method to compare invoiceList elements to lowestInvoice.
077 * assertThat(invoiceList).contains(lowestInvoice).
078 *
079 * // standard comparison : the fellowshipOfTheRing includes Gandalf but not Sauron (believe me) ...
080 * assertThat(fellowshipOfTheRing).contains(gandalf)
081 * .doesNotContain(sauron);
082 *
083 * // ... but if we compare only races, Sauron is in fellowshipOfTheRing because he's a Maia like Gandalf.
084 * assertThat(fellowshipOfTheRing).usingElementComparator(raceComparator)
085 * .contains(sauron);
086 * </pre>
087 *
088 * @param customComparator the comparator to use for incoming assertion checks.
089 * @throws NullPointerException if the given comparator is {@code null}.
090 * @return {@code this} assertion object.
091 */
092 S usingElementComparator(Comparator<? super T> customComparator);
093
094 /**
095 * Revert to standard comparison for incoming assertion group element checks.
096 * <p>
097 * This method should be used to disable a custom comparison strategy set by calling
098 * {@link #usingElementComparator(Comparator)}.
099 * @return {@code this} assertion object.
100 */
101 S usingDefaultElementComparator();
102 }