001/* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.collect.testing.testers; 018 019import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER; 020import static com.google.common.collect.testing.features.CollectionSize.ZERO; 021 022import com.google.common.annotations.GwtCompatible; 023import com.google.common.annotations.GwtIncompatible; 024import com.google.common.collect.testing.AbstractCollectionTester; 025import com.google.common.collect.testing.Helpers; 026import com.google.common.collect.testing.WrongType; 027import com.google.common.collect.testing.features.CollectionFeature; 028import com.google.common.collect.testing.features.CollectionSize; 029import java.lang.reflect.Method; 030import java.util.Arrays; 031import java.util.Collection; 032import java.util.List; 033 034/** 035 * A generic JUnit test which tests {@code toArray()} operations on a collection. Can't be invoked 036 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}. 037 * 038 * @author Kevin Bourrillion 039 * @author Chris Povirk 040 */ 041@GwtCompatible(emulated = true) 042public class CollectionToArrayTester<E> extends AbstractCollectionTester<E> { 043 public void testToArray_noArgs() { 044 Object[] array = collection.toArray(); 045 expectArrayContentsAnyOrder(createSamplesArray(), array); 046 } 047 048 /** 049 * {@link Collection#toArray(Object[])} says: "Note that <tt>toArray(new Object[0])</tt> is 050 * identical in function to <tt>toArray()</tt>." 051 * 052 * <p>For maximum effect, the collection under test should be created from an element array of a 053 * type other than {@code Object[]}. 054 */ 055 public void testToArray_isPlainObjectArray() { 056 Object[] array = collection.toArray(); 057 assertEquals(Object[].class, array.getClass()); 058 } 059 060 public void testToArray_emptyArray() { 061 E[] empty = getSubjectGenerator().createArray(0); 062 E[] array = collection.toArray(empty); 063 assertEquals( 064 "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass()); 065 assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length); 066 expectArrayContentsAnyOrder(createSamplesArray(), array); 067 } 068 069 @CollectionFeature.Require(KNOWN_ORDER) 070 public void testToArray_emptyArray_ordered() { 071 E[] empty = getSubjectGenerator().createArray(0); 072 E[] array = collection.toArray(empty); 073 assertEquals( 074 "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass()); 075 assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length); 076 expectArrayContentsInOrder(getOrderedElements(), array); 077 } 078 079 public void testToArray_emptyArrayOfObject() { 080 Object[] in = new Object[0]; 081 Object[] array = collection.toArray(in); 082 assertEquals( 083 "toArray(emptyObject[]) should return an array of type Object", 084 Object[].class, 085 array.getClass()); 086 assertEquals("toArray(emptyObject[]).length", getNumElements(), array.length); 087 expectArrayContentsAnyOrder(createSamplesArray(), array); 088 } 089 090 public void testToArray_rightSizedArray() { 091 E[] array = getSubjectGenerator().createArray(getNumElements()); 092 assertSame( 093 "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array)); 094 expectArrayContentsAnyOrder(createSamplesArray(), array); 095 } 096 097 @CollectionFeature.Require(KNOWN_ORDER) 098 public void testToArray_rightSizedArray_ordered() { 099 E[] array = getSubjectGenerator().createArray(getNumElements()); 100 assertSame( 101 "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array)); 102 expectArrayContentsInOrder(getOrderedElements(), array); 103 } 104 105 public void testToArray_rightSizedArrayOfObject() { 106 Object[] array = new Object[getNumElements()]; 107 assertSame( 108 "toArray(sameSizeObject[]) should return the given array", 109 array, 110 collection.toArray(array)); 111 expectArrayContentsAnyOrder(createSamplesArray(), array); 112 } 113 114 @CollectionFeature.Require(KNOWN_ORDER) 115 public void testToArray_rightSizedArrayOfObject_ordered() { 116 Object[] array = new Object[getNumElements()]; 117 assertSame( 118 "toArray(sameSizeObject[]) should return the given array", 119 array, 120 collection.toArray(array)); 121 expectArrayContentsInOrder(getOrderedElements(), array); 122 } 123 124 public void testToArray_oversizedArray() { 125 E[] array = getSubjectGenerator().createArray(getNumElements() + 2); 126 array[getNumElements()] = e3(); 127 array[getNumElements() + 1] = e3(); 128 assertSame( 129 "toArray(overSizedE[]) should return the given array", array, collection.toArray(array)); 130 131 List<E> subArray = Arrays.asList(array).subList(0, getNumElements()); 132 E[] expectedSubArray = createSamplesArray(); 133 for (int i = 0; i < getNumElements(); i++) { 134 assertTrue( 135 "toArray(overSizedE[]) should contain element " + expectedSubArray[i], 136 subArray.contains(expectedSubArray[i])); 137 } 138 assertNull( 139 "The array element immediately following the end of the collection should be nulled", 140 array[getNumElements()]); 141 // array[getNumElements() + 1] might or might not have been nulled 142 } 143 144 @CollectionFeature.Require(KNOWN_ORDER) 145 public void testToArray_oversizedArray_ordered() { 146 E[] array = getSubjectGenerator().createArray(getNumElements() + 2); 147 array[getNumElements()] = e3(); 148 array[getNumElements() + 1] = e3(); 149 assertSame( 150 "toArray(overSizedE[]) should return the given array", array, collection.toArray(array)); 151 152 List<E> expected = getOrderedElements(); 153 for (int i = 0; i < getNumElements(); i++) { 154 assertEquals(expected.get(i), array[i]); 155 } 156 assertNull( 157 "The array element immediately following the end of the collection should be nulled", 158 array[getNumElements()]); 159 // array[getNumElements() + 1] might or might not have been nulled 160 } 161 162 @CollectionSize.Require(absent = ZERO) 163 public void testToArray_emptyArrayOfWrongTypeForNonEmptyCollection() { 164 try { 165 WrongType[] array = new WrongType[0]; 166 collection.toArray(array); 167 fail("toArray(notAssignableTo[]) should throw"); 168 } catch (ArrayStoreException expected) { 169 } 170 } 171 172 @CollectionSize.Require(ZERO) 173 public void testToArray_emptyArrayOfWrongTypeForEmptyCollection() { 174 WrongType[] array = new WrongType[0]; 175 assertSame( 176 "toArray(sameSizeNotAssignableTo[]) should return the given array", 177 array, 178 collection.toArray(array)); 179 } 180 181 private void expectArrayContentsAnyOrder(Object[] expected, Object[] actual) { 182 Helpers.assertEqualIgnoringOrder(Arrays.asList(expected), Arrays.asList(actual)); 183 } 184 185 private void expectArrayContentsInOrder(List<E> expected, Object[] actual) { 186 assertEquals("toArray() ordered contents: ", expected, Arrays.asList(actual)); 187 } 188 189 /** 190 * Returns the {@link Method} instance for {@link #testToArray_isPlainObjectArray()} so that tests 191 * of {@link Arrays#asList(Object[])} can suppress it with {@code 192 * FeatureSpecificTestSuiteBuilder.suppressing()} until <a 193 * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6260652">Sun bug 6260652</a> is fixed. 194 */ 195 @GwtIncompatible // reflection 196 public static Method getToArrayIsPlainObjectArrayMethod() { 197 return Helpers.getMethod(CollectionToArrayTester.class, "testToArray_isPlainObjectArray"); 198 } 199}