Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 1 | // Copyright 2009 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | // Tests captures in positive and negative look-ahead in regular expressions. |
| 29 | |
| 30 | function stringEscape(string) { |
| 31 | // Converts string to source literal. |
| 32 | return '"' + string.replace(/["\\]/g, "\\$1") + '"'; |
| 33 | } |
| 34 | |
| 35 | function testRE(re, input, expected_result) { |
| 36 | var testName = re + ".test(" + stringEscape(input) +")"; |
| 37 | if (expected_result) { |
| 38 | assertTrue(re.test(input), testName); |
| 39 | } else { |
| 40 | assertFalse(re.test(input), testName); |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | function execRE(re, input, expected_result) { |
| 45 | var testName = re + ".exec('" + stringEscape(input) +"')"; |
| 46 | assertEquals(expected_result, re.exec(input), testName); |
| 47 | } |
| 48 | |
| 49 | // Test of simple positive lookahead. |
| 50 | |
| 51 | var re = /^(?=a)/; |
| 52 | testRE(re, "a", true); |
| 53 | testRE(re, "b", false); |
| 54 | execRE(re, "a", [""]); |
| 55 | |
| 56 | re = /^(?=\woo)f\w/; |
| 57 | testRE(re, "foo", true); |
| 58 | testRE(re, "boo", false); |
| 59 | testRE(re, "fao", false); |
| 60 | testRE(re, "foa", false); |
| 61 | execRE(re, "foo", ["fo"]); |
| 62 | |
| 63 | re = /(?=\w).(?=\W)/; |
| 64 | testRE(re, ".a! ", true); |
| 65 | testRE(re, ".! ", false); |
| 66 | testRE(re, ".ab! ", true); |
| 67 | execRE(re, ".ab! ", ["b"]); |
| 68 | |
| 69 | re = /(?=f(?=[^f]o))../; |
| 70 | testRE(re, ", foo!", true); |
| 71 | testRE(re, ", fo!", false); |
| 72 | testRE(re, ", ffo", false); |
| 73 | execRE(re, ", foo!", ["fo"]); |
| 74 | |
| 75 | // Positive lookahead with captures. |
| 76 | re = /^[^\'\"]*(?=([\'\"])).*\1(\w+)\1/; |
| 77 | testRE(re, " 'foo' ", true); |
| 78 | testRE(re, ' "foo" ', true); |
| 79 | testRE(re, " \" 'foo' ", false); |
| 80 | testRE(re, " ' \"foo\" ", false); |
| 81 | testRE(re, " 'foo\" ", false); |
| 82 | testRE(re, " \"foo' ", false); |
| 83 | execRE(re, " 'foo' ", [" 'foo'", "'", "foo"]); |
| 84 | execRE(re, ' "foo" ', [' "foo"', '"', 'foo']); |
| 85 | |
| 86 | // Captures are cleared on backtrack past the look-ahead. |
| 87 | re = /^(?:(?=(.))a|b)\1$/; |
| 88 | testRE(re, "aa", true); |
| 89 | testRE(re, "b", true); |
| 90 | testRE(re, "bb", false); |
| 91 | testRE(re, "a", false); |
| 92 | execRE(re, "aa", ["aa", "a"]); |
| 93 | execRE(re, "b", ["b", undefined]); |
| 94 | |
| 95 | re = /^(?=(.)(?=(.)\1\2)\2\1)\1\2/; |
| 96 | testRE(re, "abab", true); |
| 97 | testRE(re, "ababxxxxxxxx", true); |
| 98 | testRE(re, "aba", false); |
| 99 | execRE(re, "abab", ["ab", "a", "b"]); |
| 100 | |
| 101 | re = /^(?:(?=(.))a|b|c)$/; |
| 102 | testRE(re, "a", true); |
| 103 | testRE(re, "b", true); |
| 104 | testRE(re, "c", true); |
| 105 | testRE(re, "d", false); |
| 106 | execRE(re, "a", ["a", "a"]); |
| 107 | execRE(re, "b", ["b", undefined]); |
| 108 | execRE(re, "c", ["c", undefined]); |
| 109 | |
| 110 | execRE(/^(?=(b))b/, "b", ["b", "b"]); |
| 111 | execRE(/^(?:(?=(b))|a)b/, "ab", ["ab", undefined]); |
| 112 | execRE(/^(?:(?=(b)(?:(?=(c))|d))|)bd/, "bd", ["bd", "b", undefined]); |
| 113 | |
| 114 | |
| 115 | |
| 116 | // Test of Negative Look-Ahead. |
| 117 | |
| 118 | re = /(?!x)./; |
| 119 | testRE(re, "y", true); |
| 120 | testRE(re, "x", false); |
| 121 | execRE(re, "y", ["y"]); |
| 122 | |
| 123 | re = /(?!(\d))|\d/; |
| 124 | testRE(re, "4", true); |
| 125 | execRE(re, "4", ["4", undefined]); |
| 126 | execRE(re, "x", ["", undefined]); |
| 127 | |
| 128 | |
| 129 | // Test mixed nested look-ahead with captures. |
| 130 | |
| 131 | re = /^(?=(x)(?=(y)))/; |
| 132 | testRE(re, "xy", true); |
| 133 | testRE(re, "xz", false); |
| 134 | execRE(re, "xy", ["", "x", "y"]); |
| 135 | |
| 136 | re = /^(?!(x)(?!(y)))/; |
| 137 | testRE(re, "xy", true); |
| 138 | testRE(re, "xz", false); |
| 139 | execRE(re, "xy", ["", undefined, undefined]); |
| 140 | |
| 141 | re = /^(?=(x)(?!(y)))/; |
| 142 | testRE(re, "xz", true); |
| 143 | testRE(re, "xy", false) |
| 144 | execRE(re, "xz", ["", "x", undefined]); |
| 145 | |
| 146 | re = /^(?!(x)(?=(y)))/; |
| 147 | testRE(re, "xz", true); |
| 148 | testRE(re, "xy", false); |
| 149 | execRE(re, "xz", ["", undefined, undefined]); |
| 150 | |
| 151 | re = /^(?=(x)(?!(y)(?=(z))))/; |
| 152 | testRE(re, "xaz", true); |
| 153 | testRE(re, "xya", true); |
| 154 | testRE(re, "xyz", false); |
| 155 | testRE(re, "a", false); |
| 156 | execRE(re, "xaz", ["", "x", undefined, undefined]); |
| 157 | execRE(re, "xya", ["", "x", undefined, undefined]); |
| 158 | |
| 159 | re = /^(?!(x)(?=(y)(?!(z))))/; |
| 160 | testRE(re, "a", true); |
| 161 | testRE(re, "xa", true); |
| 162 | testRE(re, "xyz", true); |
| 163 | testRE(re, "xya", false); |
| 164 | execRE(re, "a", ["", undefined, undefined, undefined]); |
| 165 | execRE(re, "xa", ["", undefined, undefined, undefined]); |
| 166 | execRE(re, "xyz", ["", undefined, undefined, undefined]); |