1   /*
2    * Copyright (C) 2009 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.escape.testing;
18  
19  import static com.google.common.escape.Escapers.computeReplacement;
20  
21  import com.google.common.annotations.Beta;
22  import com.google.common.annotations.GwtCompatible;
23  import com.google.common.escape.CharEscaper;
24  import com.google.common.escape.Escaper;
25  import com.google.common.escape.UnicodeEscaper;
26  
27  import junit.framework.Assert;
28  
29  import java.io.IOException;
30  
31  /**
32   * Extra assert methods for testing Escaper implementations.
33   *
34   * @author David Beaumont
35   * @since 15.0
36   */
37  @Beta
38  @GwtCompatible
39  public final class EscaperAsserts {
40    private EscaperAsserts() {}
41  
42    /**
43     * Asserts that an escaper behaves correctly with respect to null inputs.
44     *
45     * @param escaper the non-null escaper to test
46     * @throws IOException
47     */
48    public static void assertBasic(Escaper escaper) throws IOException {
49      // Escapers operate on characters: no characters, no escaping.
50      Assert.assertEquals("", escaper.escape(""));
51      // Assert that escapers throw null pointer exceptions.
52      try {
53        escaper.escape((String) null);
54        Assert.fail("exception not thrown when escaping a null string");
55      } catch (NullPointerException e) {
56        // pass
57      }
58    }
59  
60    /**
61     * Asserts that an escaper escapes the given character into the expected
62     * string.
63     *
64     * @param escaper the non-null escaper to test
65     * @param expected the expected output string
66     * @param c the character to escape
67     */
68    public static void assertEscaping(CharEscaper escaper, String expected,
69        char c) {
70  
71      String escaped = computeReplacement(escaper, c);
72      Assert.assertNotNull(escaped);
73      Assert.assertEquals(expected, escaped);
74    }
75  
76    /**
77     * Asserts that an escaper does not escape the given character.
78     *
79     * @param escaper the non-null escaper to test
80     * @param c the character to test
81     */
82    public static void assertUnescaped(CharEscaper escaper, char c) {
83      Assert.assertNull(computeReplacement(escaper, c));
84    }
85  
86    /**
87     * Asserts that a Unicode escaper escapes the given code point into the
88     * expected string.
89     *
90     * @param escaper the non-null escaper to test
91     * @param expected the expected output string
92     * @param cp the Unicode code point to escape
93     */
94    public static void assertEscaping(UnicodeEscaper escaper, String expected,
95        int cp) {
96  
97      String escaped = computeReplacement(escaper, cp);
98      Assert.assertNotNull(escaped);
99      Assert.assertEquals(expected, escaped);
100   }
101 
102   /**
103    * Asserts that a Unicode escaper does not escape the given character.
104    *
105    * @param escaper the non-null escaper to test
106    * @param cp the Unicode code point to test
107    */
108   public static void assertUnescaped(UnicodeEscaper escaper, int cp) {
109     Assert.assertNull(computeReplacement(escaper, cp));
110   }
111 
112   /**
113    * Asserts that a Unicode escaper escapes the given hi/lo surrogate pair into
114    * the expected string.
115    *
116    * @param escaper the non-null escaper to test
117    * @param expected the expected output string
118    * @param hi the high surrogate pair character
119    * @param lo the low surrogate pair character
120    */
121   public static void assertUnicodeEscaping(UnicodeEscaper escaper,
122       String expected, char hi, char lo) {
123 
124     int cp = Character.toCodePoint(hi, lo);
125     String escaped = computeReplacement(escaper, cp);
126     Assert.assertNotNull(escaped);
127     Assert.assertEquals(expected, escaped);
128   }
129 }