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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3.tuple;
18  
19  import static org.apache.commons.lang3.LangAssertions.assertNullPointerException;
20  import static org.junit.jupiter.api.Assertions.assertEquals;
21  import static org.junit.jupiter.api.Assertions.assertNotEquals;
22  import static org.junit.jupiter.api.Assertions.assertNull;
23  
24  import java.util.HashMap;
25  import java.util.Map.Entry;
26  
27  import org.apache.commons.lang3.AbstractLangTest;
28  import org.apache.commons.lang3.SerializationUtils;
29  import org.junit.jupiter.api.Test;
30  
31  /**
32   * Test the MutablePair class.
33   */
34  class MutablePairTest extends AbstractLangTest {
35  
36      @Test
37      void testBasic() {
38          MutablePair<Integer, String> oldPair = new MutablePair<>(0, "foo");
39          MutablePair<Integer, String> nowPair;
40          for (int i = 0; i < 4; i++) {
41              nowPair = MutablePair.of(oldPair);
42              assertEquals(0, nowPair.left.intValue());
43              assertEquals(0, nowPair.getLeft().intValue());
44              assertEquals("foo", nowPair.right);
45              assertEquals("foo", nowPair.getRight());
46              assertEquals(oldPair, nowPair);
47              oldPair = nowPair;
48          }
49  
50          MutablePair<Object, String> oldPair2 = new MutablePair<>(null, "bar");
51          MutablePair<Object, String> nowPair2;
52          for (int i = 0; i < 4; i++) {
53              nowPair2 = MutablePair.of(oldPair2);
54              assertNull(nowPair2.left);
55              assertNull(nowPair2.getLeft());
56              assertEquals("bar", nowPair2.right);
57              assertEquals("bar", nowPair2.getRight());
58              oldPair2 = nowPair2;
59          }
60      }
61  
62      @Test
63      void testDefault() {
64          final MutablePair<Integer, String> pair = new MutablePair<>();
65          assertNull(pair.getLeft());
66          assertNull(pair.getRight());
67      }
68  
69      @Test
70      void testEmptyArrayGenerics() {
71          final MutablePair<Integer, String>[] empty = MutablePair.emptyArray();
72          assertEquals(0, empty.length);
73      }
74  
75      @Test
76      void testEmptyArrayLength() {
77          @SuppressWarnings("unchecked")
78          final MutablePair<Integer, String>[] empty = (MutablePair<Integer, String>[]) MutablePair.EMPTY_ARRAY;
79          assertEquals(0, empty.length);
80      }
81  
82      @Test
83      void testEquals() {
84          assertEquals(MutablePair.of(null, "foo"), MutablePair.of(null, "foo"));
85          assertNotEquals(MutablePair.of("foo", 0), MutablePair.of("foo", null));
86          assertNotEquals(MutablePair.of("foo", "bar"), MutablePair.of("xyz", "bar"));
87  
88          final MutablePair<String, String> p = MutablePair.of("foo", "bar");
89          assertEquals(p, p);
90          assertNotEquals(p, new Object());
91      }
92  
93      @Test
94      void testHashCode() {
95          assertEquals(MutablePair.of(null, "foo").hashCode(), MutablePair.of(null, "foo").hashCode());
96      }
97  
98      @Test
99      void testMutate() {
100         final MutablePair<Integer, String> pair = new MutablePair<>(0, "foo");
101         pair.setLeft(42);
102         pair.setRight("bar");
103         assertEquals(42, pair.getLeft().intValue());
104         assertEquals("bar", pair.getRight());
105     }
106 
107     @Test
108     void testOfNonNull() {
109         assertNullPointerException(() -> MutablePair.ofNonNull(null, null));
110         assertNullPointerException(() -> MutablePair.ofNonNull(null, "x"));
111         assertNullPointerException(() -> MutablePair.ofNonNull("x", null));
112         final MutablePair<String, String> pair = MutablePair.ofNonNull("x", "y");
113         assertEquals("x", pair.left);
114         assertEquals("y", pair.right);
115     }
116 
117     @Test
118     void testOfNonNullMapEntry() {
119         assertNullPointerException(() -> MutablePair.ofNonNull(null));
120         final Pair<Integer, String> pair = Pair.of(0, "foo");
121         final MutablePair<Integer, String> mutablePair = MutablePair.ofNonNull(pair);
122         assertEquals(pair.getLeft(), mutablePair.getLeft());
123         assertEquals(pair.getRight(), mutablePair.getRight());
124     }
125 
126     @Test
127     void testPairOfMapEntry() {
128         assertNull(MutablePair.of(null).getLeft());
129         assertNull(MutablePair.of(null).getRight());
130         final HashMap<Integer, String> map = new HashMap<>();
131         map.put(0, "foo");
132         final Entry<Integer, String> entry = map.entrySet().iterator().next();
133         final Pair<Integer, String> pair = MutablePair.of(entry);
134         assertEquals(entry.getKey(), pair.getLeft());
135         assertEquals(entry.getValue(), pair.getRight());
136     }
137 
138     @Test
139     void testPairOfObjects() {
140         final MutablePair<Integer, String> pair = MutablePair.of(0, "foo");
141         assertEquals(0, pair.getLeft().intValue());
142         assertEquals("foo", pair.getRight());
143         final MutablePair<Object, String> pair2 = MutablePair.of(null, "bar");
144         assertNull(pair2.getLeft());
145         assertEquals("bar", pair2.getRight());
146         final MutablePair<?, ?> pair3 = MutablePair.of(null, null);
147         assertNull(pair3.left);
148         assertNull(pair3.right);
149     }
150 
151     @Test
152     void testSerialization() throws Exception {
153         final MutablePair<Integer, String> origPair = MutablePair.of(0, "foo");
154         final MutablePair<Integer, String> deserializedPair = SerializationUtils.roundtrip(origPair);
155         assertEquals(origPair, deserializedPair);
156         assertEquals(origPair.hashCode(), deserializedPair.hashCode());
157     }
158 
159     @Test
160     void testToString() {
161         assertEquals("(null,null)", MutablePair.of(null, null).toString());
162         assertEquals("(null,two)", MutablePair.of(null, "two").toString());
163         assertEquals("(one,null)", MutablePair.of("one", null).toString());
164         assertEquals("(one,two)", MutablePair.of("one", "two").toString());
165     }
166 }