CollectionAddTester.java revision 0888a09821a98ac0680fad765217302858e70fa4 
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.ALLOWS_NULL_VALUES;
20import static com.google.common.collect.testing.features.CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;
21import static com.google.common.collect.testing.features.CollectionFeature.RESTRICTS_ELEMENTS;
22import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ADD;
23import static com.google.common.collect.testing.features.CollectionSize.ZERO;
24
25import com.google.common.annotations.GwtCompatible;
26import com.google.common.annotations.GwtIncompatible;
27import com.google.common.collect.testing.AbstractCollectionTester;
28import com.google.common.collect.testing.Helpers;
29import com.google.common.collect.testing.features.CollectionFeature;
30import com.google.common.collect.testing.features.CollectionSize;
31
32import java.lang.reflect.Method;
33import java.util.ConcurrentModificationException;
34import java.util.Iterator;
35
36/**
37 * A generic JUnit test which tests {@code add} operations on a collection.
38 * Can't be invoked directly; please see
39 * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
40 *
41 * @author Chris Povirk
42 * @author Kevin Bourrillion
43 */
44@SuppressWarnings("unchecked") // too many "unchecked generic array creations"
45@GwtCompatible(emulated = true)
46public class CollectionAddTester<E> extends AbstractCollectionTester<E> {
47  @CollectionFeature.Require(SUPPORTS_ADD)
48  public void testAdd_supportedNotPresent() {
49    assertTrue("add(notPresent) should return true",
50        collection.add(samples.e3));
51    expectAdded(samples.e3);
52  }
53
54  @CollectionFeature.Require(absent = SUPPORTS_ADD)
55  public void testAdd_unsupportedNotPresent() {
56    try {
57      collection.add(samples.e3);
58      fail("add(notPresent) should throw");
59    } catch (UnsupportedOperationException expected) {
60    }
61    expectUnchanged();
62    expectMissing(samples.e3);
63  }
64
65  @CollectionFeature.Require(absent = SUPPORTS_ADD)
66  @CollectionSize.Require(absent = ZERO)
67  public void testAdd_unsupportedPresent() {
68    try {
69      assertFalse("add(present) should return false or throw",
70          collection.add(samples.e0));
71    } catch (UnsupportedOperationException tolerated) {
72    }
73    expectUnchanged();
74  }
75
76  @CollectionFeature.Require(
77      value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES},
78      absent = RESTRICTS_ELEMENTS)
79  public void testAdd_nullSupported() {
80    assertTrue("add(null) should return true", collection.add(null));
81    expectAdded((E) null);
82  }
83
84  @CollectionFeature.Require(value = SUPPORTS_ADD,
85      absent = ALLOWS_NULL_VALUES)
86  public void testAdd_nullUnsupported() {
87    try {
88      collection.add(null);
89      fail("add(null) should throw");
90    } catch (NullPointerException expected) {
91    }
92    expectUnchanged();
93    expectNullMissingWhenNullUnsupported(
94        "Should not contain null after unsupported add(null)");
95  }
96
97  @CollectionFeature.Require({SUPPORTS_ADD,
98      FAILS_FAST_ON_CONCURRENT_MODIFICATION})
99  @CollectionSize.Require(absent = ZERO)
100  public void testAddConcurrentWithIteration() {
101    try {
102      Iterator<E> iterator = collection.iterator();
103      assertTrue(collection.add(samples.e3));
104      iterator.next();
105      fail("Expected ConcurrentModificationException");
106    } catch (ConcurrentModificationException expected) {
107      // success
108    }
109  }
110
111  /**
112   * Returns the {@link Method} instance for {@link #testAdd_nullSupported()} so
113   * that tests of {@link
114   * java.util.Collections#checkedCollection(java.util.Collection, Class)} can
115   * suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()}
116   * until <a
117   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug
118   * 6409434</a> is fixed. It's unclear whether nulls were to be permitted or
119   * forbidden, but presumably the eventual fix will be to permit them, as it
120   * seems more likely that code would depend on that behavior than on the
121   * other. Thus, we say the bug is in add(), which fails to support null.
122   */
123  @GwtIncompatible("reflection")
124  public static Method getAddNullSupportedMethod() {
125    return Helpers.getMethod(CollectionAddTester.class, "testAdd_nullSupported");
126  }
127
128  /**
129   * Returns the {@link Method} instance for {@link #testAdd_nullSupported()}
130   * so that tests of {@link java.util.TreeSet} can suppress it with {@code
131   * FeatureSpecificTestSuiteBuilder.suppressing()} until <a
132   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5045147">Sun bug
133   * 5045147</a> is fixed.
134   */
135  @GwtIncompatible("reflection")
136  public static Method getAddNullUnsupportedMethod() {
137    return Helpers.getMethod(CollectionAddTester.class, "testAdd_nullUnsupported");
138  }
139}
140