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
17package com.google.common.collect.testing.testers;
18
19import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
20import static com.google.common.collect.testing.features.CollectionSize.ZERO;
21
22import com.google.common.collect.testing.AbstractCollectionTester;
23import com.google.common.collect.testing.Helpers;
24import com.google.common.collect.testing.WrongType;
25import com.google.common.collect.testing.features.CollectionFeature;
26import com.google.common.collect.testing.features.CollectionSize;
27
28import java.lang.reflect.Method;
29import java.util.Arrays;
30import java.util.Collection;
31import java.util.List;
32
33/**
34 * A generic JUnit test which tests {@code toArray()} operations on a
35 * collection. Can't be invoked directly; please see
36 * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
37 *
38 * <p>This class is GWT compatible.
39 *
40 * @author Kevin Bourrillion
41 * @author Chris Povirk
42 */
43public class CollectionToArrayTester<E> extends AbstractCollectionTester<E> {
44  public void testToArray_noArgs() {
45    Object[] array = collection.toArray();
46    expectArrayContentsAnyOrder(createSamplesArray(), array);
47  }
48
49  /**
50   * {@link Collection#toArray(Object[])} says: "Note that
51   * <tt>toArray(new Object[0])</tt> is identical in function to
52   * <tt>toArray()</tt>."
53   *
54   * <p>For maximum effect, the collection under test should be created from an
55   * element array of a 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("toArray(emptyT[]) should return an array of type T",
66        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("toArray(emptyT[]) should return an array of type T",
76        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("toArray(emptyObject[]) should return an array of type Object",
85        Object[].class, array.getClass());
86    assertEquals("toArray(emptyObject[]).length",
87        getNumElements(), array.length);
88    expectArrayContentsAnyOrder(createSamplesArray(), array);
89  }
90
91  public void testToArray_rightSizedArray() {
92    E[] array = getSubjectGenerator().createArray(getNumElements());
93    assertSame("toArray(sameSizeE[]) should return the given array",
94        array, collection.toArray(array));
95    expectArrayContentsAnyOrder(createSamplesArray(), array);
96  }
97
98  @CollectionFeature.Require(KNOWN_ORDER)
99  public void testToArray_rightSizedArray_ordered() {
100    E[] array = getSubjectGenerator().createArray(getNumElements());
101    assertSame("toArray(sameSizeE[]) should return the given array",
102        array, collection.toArray(array));
103    expectArrayContentsInOrder(getOrderedElements(), array);
104  }
105
106  public void testToArray_rightSizedArrayOfObject() {
107    Object[] array = new Object[getNumElements()];
108    assertSame("toArray(sameSizeObject[]) should return the given array",
109        array, collection.toArray(array));
110    expectArrayContentsAnyOrder(createSamplesArray(), array);
111  }
112
113  @CollectionFeature.Require(KNOWN_ORDER)
114  public void testToArray_rightSizedArrayOfObject_ordered() {
115    Object[] array = new Object[getNumElements()];
116    assertSame("toArray(sameSizeObject[]) should return the given array",
117        array, collection.toArray(array));
118    expectArrayContentsInOrder(getOrderedElements(), array);
119  }
120
121  public void testToArray_oversizedArray() {
122    E[] array = getSubjectGenerator().createArray(getNumElements() + 2);
123    array[getNumElements()] = samples.e3;
124    array[getNumElements() + 1] = samples.e3;
125    assertSame("toArray(overSizedE[]) should return the given array",
126        array, collection.toArray(array));
127
128    List<E> subArray = Arrays.asList(array).subList(0, getNumElements());
129    E[] expectedSubArray = createSamplesArray();
130    for (int i = 0; i < getNumElements(); i++) {
131      assertTrue(
132          "toArray(overSizedE[]) should contain element " + expectedSubArray[i],
133          subArray.contains(expectedSubArray[i]));
134    }
135    assertNull("The array element "
136        + "immediately following the end of the collection should be nulled",
137        array[getNumElements()]);
138    // array[getNumElements() + 1] might or might not have been nulled
139  }
140
141  @CollectionFeature.Require(KNOWN_ORDER)
142  public void testToArray_oversizedArray_ordered() {
143    E[] array = getSubjectGenerator().createArray(getNumElements() + 2);
144    array[getNumElements()] = samples.e3;
145    array[getNumElements() + 1] = samples.e3;
146    assertSame("toArray(overSizedE[]) should return the given array",
147        array, collection.toArray(array));
148
149    List<E> expected = getOrderedElements();
150    for (int i = 0; i < getNumElements(); i++) {
151      assertEquals(expected.get(i), array[i]);
152    }
153    assertNull("The array element "
154        + "immediately following the end of the collection should be nulled",
155        array[getNumElements()]);
156    // array[getNumElements() + 1] might or might not have been nulled
157  }
158
159  @CollectionSize.Require(absent = ZERO)
160  public void testToArray_emptyArrayOfWrongTypeForNonEmptyCollection() {
161    try {
162      WrongType[] array = new WrongType[0];
163      collection.toArray(array);
164      fail("toArray(notAssignableTo[]) should throw");
165    } catch (ArrayStoreException expected) {
166    }
167  }
168
169  @CollectionSize.Require(ZERO)
170  public void testToArray_emptyArrayOfWrongTypeForEmptyCollection() {
171    WrongType[] array = new WrongType[0];
172    assertSame(
173        "toArray(sameSizeNotAssignableTo[]) should return the given array",
174        array, collection.toArray(array));
175  }
176
177  private void expectArrayContentsAnyOrder(Object[] expected, Object[] actual) {
178    Helpers.assertEqualIgnoringOrder(
179        Arrays.asList(expected), Arrays.asList(actual));
180  }
181
182  private void expectArrayContentsInOrder(List<E> expected, Object[] actual) {
183    assertEquals("toArray() ordered contents: ",
184        expected, Arrays.asList(actual));
185  }
186
187  /**
188   * Returns the {@link Method} instance for
189   * {@link #testToArray_isPlainObjectArray()} so that tests of
190   * {@link Arrays#asList(Object[])} can suppress it with {@code
191   * FeatureSpecificTestSuiteBuilder.suppressing()} until <a
192   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6260652">Sun bug
193   * 6260652</a> is fixed.
194   */
195  public static Method getToArrayIsPlainObjectArrayMethod() {
196    return Platform.getMethod(CollectionToArrayTester.class, "testToArray_isPlainObjectArray");
197  }
198}
199