1 // Copyright 2008 The RE2 Authors. All Rights Reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 // Exhaustive testing of regular expression matching.
6
7 #include <stddef.h>
8 #include <memory>
9 #include <string>
10 #include <vector>
11
12 #include "util/test.h"
13 #include "re2/testing/exhaustive_tester.h"
14
15 namespace re2 {
16
17 // Test empty string matches (aka "(?:)")
TEST(EmptyString,Exhaustive)18 TEST(EmptyString, Exhaustive) {
19 ExhaustiveTest(2, 2, Split(" ", "(?:) a"),
20 RegexpGenerator::EgrepOps(),
21 5, Split("", "ab"), "", "");
22 }
23
24 // Test escaped versions of regexp syntax.
TEST(Punctuation,Literals)25 TEST(Punctuation, Literals) {
26 std::vector<std::string> alphabet = Explode("()*+?{}[]\\^$.");
27 std::vector<std::string> escaped = alphabet;
28 for (size_t i = 0; i < escaped.size(); i++)
29 escaped[i] = "\\" + escaped[i];
30 ExhaustiveTest(1, 1, escaped, RegexpGenerator::EgrepOps(),
31 2, alphabet, "", "");
32 }
33
34 // Test ^ $ . \A \z in presence of line endings.
35 // Have to wrap the empty-width ones in (?:) so that
36 // they can be repeated -- PCRE rejects ^* but allows (?:^)*
TEST(LineEnds,Exhaustive)37 TEST(LineEnds, Exhaustive) {
38 ExhaustiveTest(2, 2, Split(" ", "(?:^) (?:$) . a \\n (?:\\A) (?:\\z)"),
39 RegexpGenerator::EgrepOps(),
40 4, Explode("ab\n"), "", "");
41 }
42
43 // Test what does and does not match \n.
44 // This would be a good test, except that PCRE seems to have a bug:
45 // in single-byte character set mode (the default),
46 // [^a] matches \n, but in UTF-8 mode it does not.
47 // So when we run the test, the tester complains that
48 // we don't agree with PCRE, but it's PCRE that is at fault.
49 // For what it's worth, Perl gets this right (matches
50 // regardless of whether UTF-8 input is selected):
51 //
52 // #!/usr/bin/perl
53 // use POSIX qw(locale_h);
54 // print "matches in latin1\n" if "\n" =~ /[^a]/;
55 // setlocale("en_US.utf8");
56 // print "matches in utf8\n" if "\n" =~ /[^a]/;
57 //
58 // The rule chosen for RE2 is that by default, like Perl,
59 // dot does not match \n but negated character classes [^a] do.
60 // (?s) will allow dot to match \n; there is no way in RE2
61 // to stop [^a] from matching \n, though the underlying library
62 // provides a mechanism, and RE2 could add new syntax if needed.
63 //
64 // TEST(Newlines, Exhaustive) {
65 // std::vector<std::string> empty_vector;
66 // ExhaustiveTest(1, 1, Split(" ", "\\n . a [^a]"),
67 // RegexpGenerator::EgrepOps(),
68 // 4, Explode("a\n"), "");
69 // }
70
71 } // namespace re2
72
73