1 /*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.google.common.collect.testing.testers;
18
19 import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
20 import static com.google.common.collect.testing.features.CollectionSize.ZERO;
21
22 import com.google.common.annotations.GwtCompatible;
23 import com.google.common.annotations.GwtIncompatible;
24 import com.google.common.collect.testing.AbstractCollectionTester;
25 import com.google.common.collect.testing.Helpers;
26 import com.google.common.collect.testing.WrongType;
27 import com.google.common.collect.testing.features.CollectionFeature;
28 import com.google.common.collect.testing.features.CollectionSize;
29 import java.lang.reflect.Method;
30 import java.util.Arrays;
31 import java.util.Collection;
32 import java.util.List;
33 import org.junit.Ignore;
34
35 /**
36 * A generic JUnit test which tests {@code toArray()} operations on a collection. Can't be invoked
37 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
38 *
39 * @author Kevin Bourrillion
40 * @author Chris Povirk
41 */
42 @GwtCompatible(emulated = true)
43 @Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
44 public class CollectionToArrayTester<E> extends AbstractCollectionTester<E> {
45 public void testToArray_noArgs() {
46 Object[] array = collection.toArray();
47 expectArrayContentsAnyOrder(createSamplesArray(), array);
48 }
49
50 /**
51 * {@link Collection#toArray(Object[])} says: "Note that <tt>toArray(new Object[0])</tt> is
52 * identical in function to <tt>toArray()</tt>."
53 *
54 * <p>For maximum effect, the collection under test should be created from an element array of a
55 * type other than {@code Object[]}.
56 */
57 public void testToArray_isPlainObjectArray() {
58 Object[] array = collection.toArray();
59 assertEquals(Object[].class, array.getClass());
60 }
61
62 public void testToArray_emptyArray() {
63 E[] empty = getSubjectGenerator().createArray(0);
64 E[] array = collection.toArray(empty);
65 assertEquals(
66 "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());
67 assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length);
68 expectArrayContentsAnyOrder(createSamplesArray(), array);
69 }
70
71 @CollectionFeature.Require(KNOWN_ORDER)
72 public void testToArray_emptyArray_ordered() {
73 E[] empty = getSubjectGenerator().createArray(0);
74 E[] array = collection.toArray(empty);
75 assertEquals(
76 "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());
77 assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length);
78 expectArrayContentsInOrder(getOrderedElements(), array);
79 }
80
81 public void testToArray_emptyArrayOfObject() {
82 Object[] in = new Object[0];
83 Object[] array = collection.toArray(in);
84 assertEquals(
85 "toArray(emptyObject[]) should return an array of type Object",
86 Object[].class,
87 array.getClass());
88 assertEquals("toArray(emptyObject[]).length", getNumElements(), array.length);
89 expectArrayContentsAnyOrder(createSamplesArray(), array);
90 }
91
92 public void testToArray_rightSizedArray() {
93 E[] array = getSubjectGenerator().createArray(getNumElements());
94 assertSame(
95 "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
96 expectArrayContentsAnyOrder(createSamplesArray(), array);
97 }
98
99 @CollectionFeature.Require(KNOWN_ORDER)
100 public void testToArray_rightSizedArray_ordered() {
101 E[] array = getSubjectGenerator().createArray(getNumElements());
102 assertSame(
103 "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
104 expectArrayContentsInOrder(getOrderedElements(), array);
105 }
106
107 public void testToArray_rightSizedArrayOfObject() {
108 Object[] array = new Object[getNumElements()];
109 assertSame(
110 "toArray(sameSizeObject[]) should return the given array",
111 array,
112 collection.toArray(array));
113 expectArrayContentsAnyOrder(createSamplesArray(), array);
114 }
115
116 @CollectionFeature.Require(KNOWN_ORDER)
117 public void testToArray_rightSizedArrayOfObject_ordered() {
118 Object[] array = new Object[getNumElements()];
119 assertSame(
120 "toArray(sameSizeObject[]) should return the given array",
121 array,
122 collection.toArray(array));
123 expectArrayContentsInOrder(getOrderedElements(), array);
124 }
125
126 public void testToArray_oversizedArray() {
127 E[] array = getSubjectGenerator().createArray(getNumElements() + 2);
128 array[getNumElements()] = e3();
129 array[getNumElements() + 1] = e3();
130 assertSame(
131 "toArray(overSizedE[]) should return the given array", array, collection.toArray(array));
132
133 List<E> subArray = Arrays.asList(array).subList(0, getNumElements());
134 E[] expectedSubArray = createSamplesArray();
135 for (int i = 0; i < getNumElements(); i++) {
136 assertTrue(
137 "toArray(overSizedE[]) should contain element " + expectedSubArray[i],
138 subArray.contains(expectedSubArray[i]));
139 }
140 assertNull(
141 "The array element immediately following the end of the collection should be nulled",
142 array[getNumElements()]);
143 // array[getNumElements() + 1] might or might not have been nulled
144 }
145
146 @CollectionFeature.Require(KNOWN_ORDER)
147 public void testToArray_oversizedArray_ordered() {
148 E[] array = getSubjectGenerator().createArray(getNumElements() + 2);
149 array[getNumElements()] = e3();
150 array[getNumElements() + 1] = e3();
151 assertSame(
152 "toArray(overSizedE[]) should return the given array", array, collection.toArray(array));
153
154 List<E> expected = getOrderedElements();
155 for (int i = 0; i < getNumElements(); i++) {
156 assertEquals(expected.get(i), array[i]);
157 }
158 assertNull(
159 "The array element immediately following the end of the collection should be nulled",
160 array[getNumElements()]);
161 // array[getNumElements() + 1] might or might not have been nulled
162 }
163
164 @CollectionSize.Require(absent = ZERO)
165 public void testToArray_emptyArrayOfWrongTypeForNonEmptyCollection() {
166 try {
167 WrongType[] array = new WrongType[0];
168 collection.toArray(array);
169 fail("toArray(notAssignableTo[]) should throw");
170 } catch (ArrayStoreException expected) {
171 }
172 }
173
174 @CollectionSize.Require(ZERO)
175 public void testToArray_emptyArrayOfWrongTypeForEmptyCollection() {
176 WrongType[] array = new WrongType[0];
177 assertSame(
178 "toArray(sameSizeNotAssignableTo[]) should return the given array",
179 array,
180 collection.toArray(array));
181 }
182
183 private void expectArrayContentsAnyOrder(Object[] expected, Object[] actual) {
184 Helpers.assertEqualIgnoringOrder(Arrays.asList(expected), Arrays.asList(actual));
185 }
186
187 private void expectArrayContentsInOrder(List<E> expected, Object[] actual) {
188 assertEquals("toArray() ordered contents: ", expected, Arrays.asList(actual));
189 }
190
191 /**
192 * Returns the {@link Method} instance for {@link #testToArray_isPlainObjectArray()} so that tests
193 * of {@link Arrays#asList(Object[])} can suppress it with {@code
194 * FeatureSpecificTestSuiteBuilder.suppressing()} until <a
195 * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6260652">Sun bug 6260652</a> is fixed.
196 */
197 @GwtIncompatible // reflection
198 public static Method getToArrayIsPlainObjectArrayMethod() {
199 return Helpers.getMethod(CollectionToArrayTester.class, "testToArray_isPlainObjectArray");
200 }
201 }