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;
18  
19  import static com.google.common.truth.Truth.assertThat;
20  
21  import com.google.common.annotations.GwtCompatible;
22  import com.google.common.annotations.GwtIncompatible;
23  import com.google.common.testing.NullPointerTester;
24  
25  import junit.framework.TestCase;
26  
27  import java.io.Serializable;
28  import java.util.Arrays;
29  import java.util.List;
30  
31  /**
32   * Unit test for {@code ObjectArrays}.
33   *
34   * @author Kevin Bourrillion
35   */
36  @GwtCompatible(emulated = true)
37  public class ObjectArraysTest extends TestCase {
38  
39    @GwtIncompatible("NullPointerTester")
40    public void testNullPointerExceptions() {
41      NullPointerTester tester = new NullPointerTester();
42      tester.testAllPublicStaticMethods(ObjectArrays.class);
43    }
44  
45    @GwtIncompatible("ObjectArrays.newArray(Class, int)")
46    public void testNewArray_fromClass_Empty() {
47      String[] empty = ObjectArrays.newArray(String.class, 0);
48      assertEquals(String[].class, empty.getClass());
49      assertEquals(0, empty.length);
50    }
51  
52    @GwtIncompatible("ObjectArrays.newArray(Class, int)")
53    public void testNewArray_fromClass_Nonempty() {
54      String[] array = ObjectArrays.newArray(String.class, 2);
55      assertEquals(String[].class, array.getClass());
56      assertEquals(2, array.length);
57      assertNull(array[0]);
58    }
59  
60    @GwtIncompatible("ObjectArrays.newArray(Class, int)")
61    public void testNewArray_fromClass_OfArray() {
62      String[][] array = ObjectArrays.newArray(String[].class, 1);
63      assertEquals(String[][].class, array.getClass());
64      assertEquals(1, array.length);
65      assertNull(array[0]);
66    }
67  
68    public void testNewArray_fromArray_Empty() {
69      String[] in = new String[0];
70      String[] empty = ObjectArrays.newArray(in, 0);
71      assertEquals(0, empty.length);
72    }
73  
74    public void testNewArray_fromArray_Nonempty() {
75      String[] array = ObjectArrays.newArray(new String[0], 2);
76      assertEquals(String[].class, array.getClass());
77      assertEquals(2, array.length);
78      assertNull(array[0]);
79    }
80  
81    public void testNewArray_fromArray_OfArray() {
82      String[][] array = ObjectArrays.newArray(new String[0][0], 1);
83      assertEquals(String[][].class, array.getClass());
84      assertEquals(1, array.length);
85      assertNull(array[0]);
86    }
87  
88    @GwtIncompatible("ObjectArrays.concat(Object[], Object[], Class)")
89    public void testConcatEmptyEmpty() {
90      String[] result
91          = ObjectArrays.concat(new String[0], new String[0], String.class);
92      assertEquals(String[].class, result.getClass());
93      assertEquals(0, result.length);
94    }
95  
96    @GwtIncompatible("ObjectArrays.concat(Object[], Object[], Class)")
97    public void testConcatEmptyNonempty() {
98      String[] result = ObjectArrays.concat(
99          new String[0], new String[] { "a", "b" }, String.class);
100     assertEquals(String[].class, result.getClass());
101     assertThat(result).asList().has().exactly("a", "b").inOrder();
102   }
103 
104   @GwtIncompatible("ObjectArrays.concat(Object[], Object[], Class)")
105   public void testConcatNonemptyEmpty() {
106     String[] result = ObjectArrays.concat(
107         new String[] { "a", "b" }, new String[0], String.class);
108     assertEquals(String[].class, result.getClass());
109     assertThat(result).asList().has().exactly("a", "b").inOrder();
110   }
111 
112   @GwtIncompatible("ObjectArrays.concat(Object[], Object[], Class)")
113   public void testConcatBasic() {
114     String[] result = ObjectArrays.concat(
115         new String[] { "a", "b" }, new String[] { "c", "d" }, String.class);
116     assertEquals(String[].class, result.getClass());
117     assertThat(result).asList().has().exactly("a", "b", "c", "d").inOrder();
118   }
119 
120   @GwtIncompatible("ObjectArrays.concat(Object[], Object[], Class)")
121   public void testConcatWithMoreGeneralType() {
122     Serializable[] result
123         = ObjectArrays.concat(new String[0], new String[0], Serializable.class);
124     assertEquals(Serializable[].class, result.getClass());
125   }
126 
127   public void testToArrayImpl1() {
128     doTestToArrayImpl1(Lists.<Integer>newArrayList());
129     doTestToArrayImpl1(Lists.newArrayList(1));
130     doTestToArrayImpl1(Lists.newArrayList(1, null, 3));
131   }
132 
133   private void doTestToArrayImpl1(List<Integer> list) {
134     Object[] reference = list.toArray();
135     Object[] target = ObjectArrays.toArrayImpl(list);
136     assertEquals(reference.getClass(), target.getClass());
137     assertTrue(Arrays.equals(reference, target));
138   }
139 
140   public void testToArrayImpl2() {
141     doTestToArrayImpl2(Lists.<Integer>newArrayList(), new Integer[0], false);
142     doTestToArrayImpl2(Lists.<Integer>newArrayList(), new Integer[1], true);
143 
144     doTestToArrayImpl2(Lists.newArrayList(1), new Integer[0], false);
145     doTestToArrayImpl2(Lists.newArrayList(1), new Integer[1], true);
146     doTestToArrayImpl2(Lists.newArrayList(1), new Integer[] { 2, 3 }, true);
147 
148     doTestToArrayImpl2(Lists.newArrayList(1, null, 3), new Integer[0], false);
149     doTestToArrayImpl2(Lists.newArrayList(1, null, 3), new Integer[2], false);
150     doTestToArrayImpl2(Lists.newArrayList(1, null, 3), new Integer[3], true);
151   }
152 
153   private void doTestToArrayImpl2(List<Integer> list, Integer[] array1,
154       boolean expectModify) {
155     Integer[] starting = ObjectArrays.arraysCopyOf(array1, array1.length);
156     Integer[] array2 = ObjectArrays.arraysCopyOf(array1, array1.length);
157     Object[] reference = list.toArray(array1);
158 
159     Object[] target = ObjectArrays.toArrayImpl(list, array2);
160 
161     assertEquals(reference.getClass(), target.getClass());
162     assertTrue(Arrays.equals(reference, target));
163     assertTrue(Arrays.equals(reference, target));
164 
165     Object[] expectedArray1 = expectModify ? reference : starting;
166     Object[] expectedArray2 = expectModify ? target : starting;
167     assertTrue(Arrays.equals(expectedArray1, array1));
168     assertTrue(Arrays.equals(expectedArray2, array2));
169   }
170 
171   public void testPrependZeroElements() {
172     String[] result = ObjectArrays.concat("foo", new String[] {});
173     assertThat(result).asList().has().item("foo");
174   }
175 
176   public void testPrependOneElement() {
177     String[] result = ObjectArrays.concat("foo", new String[] { "bar" });
178     assertThat(result).asList().has().exactly("foo", "bar").inOrder();
179   }
180 
181   public void testPrependTwoElements() {
182     String[] result = ObjectArrays.concat("foo", new String[] { "bar", "baz" });
183     assertThat(result).asList().has().exactly("foo", "bar", "baz").inOrder();
184   }
185 
186   public void testAppendZeroElements() {
187     String[] result = ObjectArrays.concat(new String[] {}, "foo");
188     assertThat(result).asList().has().item("foo");
189   }
190 
191   public void testAppendOneElement() {
192     String[] result = ObjectArrays.concat(new String[] { "foo" }, "bar");
193     assertThat(result).asList().has().exactly("foo", "bar").inOrder();
194   }
195 
196   public void testAppendTwoElements() {
197     String[] result = ObjectArrays.concat(new String[] { "foo", "bar" }, "baz");
198     assertThat(result).asList().has().exactly("foo", "bar", "baz").inOrder();
199   }
200 
201   public void testEmptyArrayToEmpty() {
202     doTestNewArrayEquals(new Object[0], 0);
203   }
204 
205   public void testEmptyArrayToNonEmpty() {
206     checkArrayEquals(new Long[5], ObjectArrays.newArray(new Long[0], 5));
207   }
208 
209   public void testNonEmptyToShorter() {
210     checkArrayEquals(new String[9], ObjectArrays.newArray(new String[10], 9));
211   }
212 
213   public void testNonEmptyToSameLength() {
214     doTestNewArrayEquals(new String[10], 10);
215   }
216 
217   public void testNonEmptyToLonger() {
218     checkArrayEquals(new String[10],
219         ObjectArrays.newArray(new String[] { "a", "b", "c", "d", "e" }, 10));
220   }
221 
222   private static void checkArrayEquals(Object[] expected, Object[] actual) {
223     assertTrue("expected(" + expected.getClass() + "): " + Arrays.toString(expected)
224         + " actual(" + actual.getClass() + "): " + Arrays.toString(actual),
225         arrayEquals(expected, actual));
226   }
227 
228   private static boolean arrayEquals(Object[] array1, Object[] array2) {
229     assertSame(array1.getClass(), array2.getClass());
230     return Arrays.equals(array1, array2);
231   }
232 
233   private static void doTestNewArrayEquals(Object[] expected, int length) {
234     checkArrayEquals(expected, ObjectArrays.newArray(expected, length));
235   }
236 }