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;
033import org.junit.Ignore;
034
035/**
036 * A generic JUnit test which tests {@code toArray()} operations on a collection. Can't be invoked
037 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
038 *
039 * @author Kevin Bourrillion
040 * @author Chris Povirk
041 */
042@GwtCompatible(emulated = true)
043@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
044public class CollectionToArrayTester<E> extends AbstractCollectionTester<E> {
045  public void testToArray_noArgs() {
046    Object[] array = collection.toArray();
047    expectArrayContentsAnyOrder(createSamplesArray(), array);
048  }
049
050  /**
051   * {@link Collection#toArray(Object[])} says: "Note that {@code toArray(new Object[0])} is
052   * identical in function to {@code toArray()}."
053   *
054   * <p>For maximum effect, the collection under test should be created from an element array of a
055   * type other than {@code Object[]}.
056   */
057  public void testToArray_isPlainObjectArray() {
058    Object[] array = collection.toArray();
059    assertEquals(Object[].class, array.getClass());
060  }
061
062  public void testToArray_emptyArray() {
063    E[] empty = getSubjectGenerator().createArray(0);
064    E[] array = collection.toArray(empty);
065    assertEquals(
066        "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());
067    assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length);
068    expectArrayContentsAnyOrder(createSamplesArray(), array);
069  }
070
071  @CollectionFeature.Require(KNOWN_ORDER)
072  public void testToArray_emptyArray_ordered() {
073    E[] empty = getSubjectGenerator().createArray(0);
074    E[] array = collection.toArray(empty);
075    assertEquals(
076        "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());
077    assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length);
078    expectArrayContentsInOrder(getOrderedElements(), array);
079  }
080
081  public void testToArray_emptyArrayOfObject() {
082    Object[] in = new Object[0];
083    Object[] array = collection.toArray(in);
084    assertEquals(
085        "toArray(emptyObject[]) should return an array of type Object",
086        Object[].class,
087        array.getClass());
088    assertEquals("toArray(emptyObject[]).length", getNumElements(), array.length);
089    expectArrayContentsAnyOrder(createSamplesArray(), array);
090  }
091
092  public void testToArray_rightSizedArray() {
093    E[] array = getSubjectGenerator().createArray(getNumElements());
094    assertSame(
095        "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
096    expectArrayContentsAnyOrder(createSamplesArray(), array);
097  }
098
099  @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}