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