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.CollectionSize.ZERO;
20  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
21  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
22  
23  import com.google.common.annotations.GwtCompatible;
24  import com.google.common.collect.testing.AbstractMapTester;
25  import com.google.common.collect.testing.WrongType;
26  import com.google.common.collect.testing.features.CollectionSize;
27  import com.google.common.collect.testing.features.MapFeature;
28  
29  /**
30   * A generic JUnit test which tests {@code get} operations on a map. Can't be
31   * invoked directly; please see
32   * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
33   *
34   * @author Kevin Bourrillion
35   * @author Chris Povirk
36   */
37  @GwtCompatible
38  public class MapGetTester<K, V> extends AbstractMapTester<K, V> {
39    @CollectionSize.Require(absent = ZERO)
40    public void testGet_yes() {
41      assertEquals("get(present) should return the associated value",
42          samples.e0.getValue(), get(samples.e0.getKey()));
43    }
44  
45    public void testGet_no() {
46      assertNull("get(notPresent) should return null", get(samples.e3.getKey()));
47    }
48  
49    @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
50    public void testGet_nullNotContainedButAllowed() {
51      assertNull("get(null) should return null", get(null));
52    }
53  
54    @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
55    public void testGet_nullNotContainedAndUnsupported() {
56      try {
57        assertNull("get(null) should return null or throw", get(null));
58      } catch (NullPointerException tolerated) {
59      }
60    }
61  
62    @MapFeature.Require(ALLOWS_NULL_KEYS)
63    @CollectionSize.Require(absent = ZERO)
64    public void testGet_nonNullWhenNullContained() {
65      initMapWithNullKey();
66      assertNull("get(notPresent) should return null", get(samples.e3.getKey()));
67    }
68  
69    @MapFeature.Require(ALLOWS_NULL_KEYS)
70    @CollectionSize.Require(absent = ZERO)
71    public void testGet_nullContained() {
72      initMapWithNullKey();
73      assertEquals("get(null) should return the associated value",
74          getValueForNullKey(), get(null));
75    }
76  
77    public void testGet_wrongType() {
78      try {
79        assertNull("get(wrongType) should return null or throw",
80            getMap().get(WrongType.VALUE));
81      } catch (ClassCastException tolerated) {
82      }
83    }
84  }