AbstractMapEntryTest.java revision 1d580d0f6ee4f21eb309ba7b509d2c6d671c4044 
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;
18
19import com.google.common.annotations.GwtCompatible;
20
21import junit.framework.TestCase;
22
23import java.util.Collections;
24import java.util.Map.Entry;
25
26/**
27 * Tests for {@code AbstractMapEntry}.
28 *
29 * @author Mike Bostock
30 */
31@GwtCompatible
32public class AbstractMapEntryTest extends TestCase {
33  private static final String NK = null;
34  private static final Integer NV = null;
35
36  private static <K, V> Entry<K, V> entry(final K key, final V value) {
37    return new AbstractMapEntry<K, V>() {
38        @Override public K getKey() {
39          return key;
40        }
41        @Override public V getValue() {
42          return value;
43        }
44      };
45  }
46
47  private static <K, V> Entry<K, V> control(K key, V value) {
48    return Collections.singletonMap(key, value).entrySet().iterator().next();
49  }
50
51  public void testToString() {
52    assertEquals("foo=1", entry("foo", 1).toString());
53  }
54
55  public void testToStringNull() {
56    assertEquals("null=1", entry(NK, 1).toString());
57    assertEquals("foo=null", entry("foo", NV).toString());
58    assertEquals("null=null", entry(NK, NV).toString());
59  }
60
61  public void testEquals() {
62    Entry<String, Integer> foo1 = entry("foo", 1);
63    assertEquals(foo1, foo1);
64    assertEquals(control("foo", 1), foo1);
65    assertEquals(control("bar", 2), entry("bar", 2));
66    assertFalse(control("foo", 1).equals(entry("foo", 2)));
67    assertFalse(foo1.equals(control("bar", 1)));
68    assertFalse(foo1.equals(new Object()));
69    assertFalse(foo1.equals(null));
70  }
71
72  public void testEqualsNull() {
73    assertEquals(control(NK, 1), entry(NK, 1));
74    assertEquals(control("bar", NV), entry("bar", NV));
75    assertFalse(control(NK, 1).equals(entry(NK, 2)));
76    assertFalse(entry(NK, 1).equals(control("bar", 1)));
77    assertFalse(entry(NK, 1).equals(new Object()));
78    assertFalse(entry(NK, 1).equals(null));
79  }
80
81  public void testHashCode() {
82    assertEquals(control("foo", 1).hashCode(), entry("foo", 1).hashCode());
83    assertEquals(control("bar", 2).hashCode(), entry("bar", 2).hashCode());
84  }
85
86  public void testHashCodeNull() {
87    assertEquals(control(NK, 1).hashCode(), entry(NK, 1).hashCode());
88    assertEquals(control("bar", NV).hashCode(), entry("bar", NV).hashCode());
89    assertEquals(control(NK, NV).hashCode(), entry(NK, NV).hashCode());
90  }
91}
92