1   /*
2    * Copyright (C) 2006 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.base;
18  
19  import com.google.common.annotations.GwtCompatible;
20  
21  import junit.framework.TestCase;
22  
23  /**
24   * Tests for {@link Objects}.
25   *
26   * @author Laurence Gonsalves
27   */
28  @GwtCompatible(emulated = true)
29  public class ObjectsTest extends TestCase {
30  
31    public void testEqual() throws Exception {
32      assertTrue(Objects.equal(1, 1));
33      assertTrue(Objects.equal(null, null));
34  
35      // test distinct string objects
36      String s1 = "foobar";
37      String s2 = new String(s1);
38      assertTrue(Objects.equal(s1, s2));
39  
40      assertFalse(Objects.equal(s1, null));
41      assertFalse(Objects.equal(null, s1));
42      assertFalse(Objects.equal("foo", "bar"));
43      assertFalse(Objects.equal("1", 1));
44    }
45  
46    public void testHashCode() throws Exception {
47      int h1 = Objects.hashCode(1, "two", 3.0);
48      int h2 = Objects.hashCode(
49          new Integer(1), new String("two"), new Double(3.0));
50      // repeatable
51      assertEquals(h1, h2);
52  
53      // These don't strictly need to be true, but they're nice properties.
54      assertTrue(Objects.hashCode(1, 2, null) != Objects.hashCode(1, 2));
55      assertTrue(Objects.hashCode(1, 2, null) != Objects.hashCode(1, null, 2));
56      assertTrue(Objects.hashCode(1, null, 2) != Objects.hashCode(1, 2));
57      assertTrue(Objects.hashCode(1, 2, 3) != Objects.hashCode(3, 2, 1));
58      assertTrue(Objects.hashCode(1, 2, 3) != Objects.hashCode(2, 3, 1));
59    }
60  
61    public void testFirstNonNull_withNonNull() throws Exception {
62      String s1 = "foo";
63      String s2 = Objects.firstNonNull(s1, "bar");
64      assertSame(s1, s2);
65  
66      Long n1 = new Long(42);
67      Long n2 = Objects.firstNonNull(null, n1);
68      assertSame(n1, n2);
69    }
70  
71    public void testFirstNonNull_throwsNullPointerException() throws Exception {
72      try {
73        Objects.firstNonNull(null, null);
74        fail("expected NullPointerException");
75      } catch (NullPointerException expected) {
76      }
77    }
78  }
79