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.ALLOWS_NULL_VALUES;
20  import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ADD;
21  import static com.google.common.collect.testing.features.CollectionSize.ZERO;
22  
23  import com.google.common.annotations.GwtCompatible;
24  import com.google.common.annotations.GwtIncompatible;
25  import com.google.common.collect.testing.Helpers;
26  import com.google.common.collect.testing.features.CollectionFeature;
27  import com.google.common.collect.testing.features.CollectionSize;
28  
29  import java.lang.reflect.Method;
30  import java.util.List;
31  
32  /**
33   * A generic JUnit test which tests {@code add(Object)} operations on a list.
34   * Can't be invoked directly; please see
35   * {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
36   *
37   * @author Chris Povirk
38   */
39  @SuppressWarnings("unchecked") // too many "unchecked generic array creations"
40  @GwtCompatible(emulated = true)
41  public class ListAddTester<E> extends AbstractListTester<E> {
42    @CollectionFeature.Require(SUPPORTS_ADD)
43    @CollectionSize.Require(absent = ZERO)
44    public void testAdd_supportedPresent() {
45      assertTrue("add(present) should return true", getList().add(samples.e0));
46      expectAdded(samples.e0);
47    }
48  
49    @CollectionFeature.Require(absent = SUPPORTS_ADD)
50    @CollectionSize.Require(absent = ZERO)
51    /*
52     * absent = ZERO isn't required, since unmodList.add() must
53     * throw regardless, but it keeps the method name accurate.
54     */
55    public void testAdd_unsupportedPresent() {
56      try {
57        getList().add(samples.e0);
58        fail("add(present) should throw");
59      } catch (UnsupportedOperationException expected) {
60      }
61    }
62  
63    @CollectionFeature.Require(value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES})
64    @CollectionSize.Require(absent = ZERO)
65    public void testAdd_supportedNullPresent() {
66      E[] array = createArrayWithNullElement();
67      collection = getSubjectGenerator().create(array);
68      assertTrue("add(nullPresent) should return true", getList().add(null));
69  
70      List<E> expected = Helpers.copyToList(array);
71      expected.add(null);
72      expectContents(expected);
73    }
74  
75    /**
76     * Returns the {@link Method} instance for
77     * {@link #testAdd_supportedNullPresent()} so that tests can suppress it. See
78     * {@link CollectionAddTester#getAddNullSupportedMethod()} for details.
79     */
80    @GwtIncompatible("reflection")
81    public static Method getAddSupportedNullPresentMethod() {
82      return Helpers.getMethod(ListAddTester.class, "testAdd_supportedNullPresent");
83    }
84  }