1   /*
2    * Copyright (C) 2008 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.primitives;
18  
19  import com.google.common.annotations.GwtCompatible;
20  import com.google.common.annotations.GwtIncompatible;
21  import com.google.common.collect.testing.Helpers;
22  import com.google.common.testing.NullPointerTester;
23  import com.google.common.testing.SerializableTester;
24  
25  import junit.framework.TestCase;
26  
27  import java.util.Arrays;
28  import java.util.Comparator;
29  import java.util.List;
30  
31  /**
32   * Unit test for {@link SignedBytes}.
33   *
34   * @author Kevin Bourrillion
35   */
36  @GwtCompatible(emulated = true)
37  @SuppressWarnings("cast") // redundant casts are intentional and harmless
38  public class SignedBytesTest extends TestCase {
39    private static final byte[] EMPTY = {};
40    private static final byte[] ARRAY1 = {(byte) 1};
41  
42    private static final byte LEAST = Byte.MIN_VALUE;
43    private static final byte GREATEST = Byte.MAX_VALUE;
44  
45    private static final byte[] VALUES =
46        {LEAST, -1, 0, 1, GREATEST};
47  
48    public void testCheckedCast() {
49      for (byte value : VALUES) {
50        assertEquals(value, SignedBytes.checkedCast((long) value));
51      }
52      assertCastFails(GREATEST + 1L);
53      assertCastFails(LEAST - 1L);
54      assertCastFails(Long.MAX_VALUE);
55      assertCastFails(Long.MIN_VALUE);
56    }
57  
58    public void testSaturatedCast() {
59      for (byte value : VALUES) {
60        assertEquals(value, SignedBytes.saturatedCast((long) value));
61      }
62      assertEquals(GREATEST, SignedBytes.saturatedCast(GREATEST + 1L));
63      assertEquals(LEAST, SignedBytes.saturatedCast(LEAST - 1L));
64      assertEquals(GREATEST, SignedBytes.saturatedCast(Long.MAX_VALUE));
65      assertEquals(LEAST, SignedBytes.saturatedCast(Long.MIN_VALUE));
66    }
67  
68    private static void assertCastFails(long value) {
69      try {
70        SignedBytes.checkedCast(value);
71        fail("Cast to byte should have failed: " + value);
72      } catch (IllegalArgumentException ex) {
73        assertTrue(value + " not found in exception text: " + ex.getMessage(),
74            ex.getMessage().contains(String.valueOf(value)));
75      }
76    }
77  
78    public void testCompare() {
79      for (byte x : VALUES) {
80        for (byte y : VALUES) {
81          // Only compare the sign of the result of compareTo().
82          int expected = Byte.valueOf(x).compareTo(y);
83          int actual = SignedBytes.compare(x, y);
84          if (expected == 0) {
85            assertEquals(x + ", " + y, expected, actual);
86          } else if (expected < 0) {
87            assertTrue(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")",
88                actual < 0);
89          } else {
90            assertTrue(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")",
91                actual > 0);
92          }
93        }
94      }
95    }
96  
97    public void testMax_noArgs() {
98      try {
99        SignedBytes.max();
100       fail();
101     } catch (IllegalArgumentException expected) {
102     }
103   }
104 
105   public void testMax() {
106     assertEquals(LEAST, SignedBytes.max(LEAST));
107     assertEquals(GREATEST, SignedBytes.max(GREATEST));
108     assertEquals((byte) 127, SignedBytes.max(
109         (byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
110   }
111 
112   public void testMin_noArgs() {
113     try {
114       SignedBytes.min();
115       fail();
116     } catch (IllegalArgumentException expected) {
117     }
118   }
119 
120   public void testMin() {
121     assertEquals(LEAST, SignedBytes.min(LEAST));
122     assertEquals(GREATEST, SignedBytes.min(GREATEST));
123     assertEquals((byte) -128, SignedBytes.min(
124         (byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
125   }
126 
127   public void testJoin() {
128     assertEquals("", SignedBytes.join(",", EMPTY));
129     assertEquals("1", SignedBytes.join(",", ARRAY1));
130     assertEquals("1,2", SignedBytes.join(",", (byte) 1, (byte) 2));
131     assertEquals("123", SignedBytes.join("", (byte) 1, (byte) 2, (byte) 3));
132     assertEquals("-128,-1", SignedBytes.join(",", (byte) -128, (byte) -1));
133   }
134 
135   public void testLexicographicalComparator() {
136     List<byte[]> ordered = Arrays.asList(
137         new byte[] {},
138         new byte[] {LEAST},
139         new byte[] {LEAST, LEAST},
140         new byte[] {LEAST, (byte) 1},
141         new byte[] {(byte) 1},
142         new byte[] {(byte) 1, LEAST},
143         new byte[] {GREATEST, GREATEST - (byte) 1},
144         new byte[] {GREATEST, GREATEST},
145         new byte[] {GREATEST, GREATEST, GREATEST});
146 
147     Comparator<byte[]> comparator = SignedBytes.lexicographicalComparator();
148     Helpers.testComparator(comparator, ordered);
149   }
150 
151   @GwtIncompatible("SerializableTester")
152   public void testLexicographicalComparatorSerializable() {
153     Comparator<byte[]> comparator = SignedBytes.lexicographicalComparator();
154     assertSame(comparator, SerializableTester.reserialize(comparator));
155   }
156 
157   @GwtIncompatible("NullPointerTester")
158   public void testNulls() {
159     new NullPointerTester().testAllPublicStaticMethods(SignedBytes.class);
160   }
161 }