1Test::LongString(3) User Contributed Perl Documentation Test::LongString(3)
2
6 Test::LongString - tests strings for equality, with more helpful
7 failures
8
10 use Test::More tests => 1;
11 use Test::LongString;
12 like_string( $html, qr/(perl|cpan)\.org/ );
13 # Failed test (html-test.t at line 12)
15 # got: "<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Trans"...
16 # length: 58930
17 # doesn't match '(?-xism:(perl|cpan)\.org)'
18
20 This module provides some drop-in replacements for the string
21 comparison functions of Test::More, but which are more suitable when
22 you test against long strings. If you've ever had to search for text
23 in a multi-line string like an HTML document, or find specific items in
24 binary data, this is the module for you.
25
27 is_string( $string, $expected [, $label ] )
28 "is_string()" is equivalent to "Test::More::is()", but with more
29 helpful diagnostics in case of failure.
30 • It doesn't print the entire strings in the failure message.
32 • It reports the lengths of the strings that have been compared.
34 • It reports the length of the common prefix of the strings.
36 • It reports the line and column the strings started to differ on.
38 • In the diagnostics, non-ASCII characters are escaped as "\x{xx}".
40 For example:
42 is_string( $soliloquy, $juliet );
44 # Failed test (soliloquy.t at line 15)
46 # got: "To be, or not to be: that is the question:\x{0a}Whether"...
47 # length: 1490
48 # expected: "O Romeo, Romeo,\x{0a}wherefore art thou Romeo?\x{0a}Deny thy"...
49 # length: 154
50 # strings begin to differ at char 1 (line 1 column 1)
51 is_string_nows( $string, $expected [, $label ] )
53 Like "is_string()", but removes whitespace (in the "\s" sense) from the
54 arguments before comparing them.
55 like_string( $string, qr/regex/ [, $label ] )
57 unlike_string( $string, qr/regex/ [, $label ] )
58 "like_string()" and "unlike_string()" are replacements for
59 "Test::More:like()" and "unlike()" that only print the beginning of the
60 received string in the output. Unfortunately, they can't print out the
61 position where the regex failed to match.
62 like_string( $soliloquy, qr/Romeo|Juliet|Mercutio|Tybalt/ );
64 # Failed test (soliloquy.t at line 15)
66 # got: "To be, or not to be: that is the question:\x{0a}Whether"...
67 # length: 1490
68 # doesn't match '(?-xism:Romeo|Juliet|Mercutio|Tybalt)'
69 contains_string( $string, $substring [, $label ] )
71 "contains_string()" searches for $substring in $string. It's the same
72 as "like_string()", except that it's not a regular expression search.
73 contains_string( $soliloquy, "Romeo" );
75 # Failed test (soliloquy.t at line 10)
77 # searched: "To be, or not to be: that is the question:\x{0a}Whether"...
78 # and can't find: "Romeo"
79 As of version 0.12, "contains_string()" will also report the Longest
81 Common SubString (LCSS) found in $string and, if the LCSS is short
82 enough, the surroundings will also be shown under LCSS Context. This
83 should help debug tests for really long strings like HTML output, so
84 you'll get something like:
85 contains_string( $html, '<div id="MainContent">' );
87 # Failed test at t/foo.t line 10.
88 # searched: "<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric"...
89 # can't find: "<div id="MainContent">"
90 # LCSS: "ainContent""
91 # LCSS context: "dolor sit amet</span>\x{0a}<div id="mainContent" class="
92 You can turn off LCSS reporting by setting $Test::LongString::LCSS to
94 0, or by specifying an argument to "use":
95 use Test::LongString lcss => 0;
97 lacks_string( $string, $substring [, $label ] )
99 "lacks_string()" makes sure that $substring does NOT exist in $string.
100 It's the same as "like_string()", except that it's not a regular
101 expression search.
102 lacks_string( $soliloquy, "slings" );
104 # Failed test (soliloquy.t at line 10)
106 # searched: "To be, or not to be: that is the question:\x{0a}Whether"...
107 # and found: "slings"
108 # at position: 147 (line 3 column 4)
109
111 By default, only the first 50 characters of the compared strings are
112 shown in the failure message. This value is in $Test::LongString::Max,
113 and can be set at run-time.
114 You can also set it by specifying an argument to "use":
116 use Test::LongString max => 100;
118 When the compared strings begin to differ after a large prefix,
120 Test::LongString will not print them from the beginning, but will start
121 at the middle, more precisely at $Test::LongString::Context characters
122 before the first difference. By default this value is 10 characters. If
123 you want Test::LongString to always print the beginning of compared
124 strings no matter where they differ, undefine
125 $Test::LongString::Context.
126 When computing line numbers this module uses "\n" to count line
128 endings. This may not be appropriate for strings on your platform, and
129 can be overridden by setting the $Test::LongString::EOL variable to a
130 suitable regular expression (either a reference to a regular expression
131 or a string that can be interpolated into a regular expression.)
132 You can also set it by specifying an argument to "use":
134 use Test::LongString eol => "\x{0a}\x{0c}";
136
138 Written by Rafael Garcia-Suarez. Thanks to Mark Fowler (and to Joss
139 Whedon) for the inspirational Acme::Test::Buffy. Thanks to Andy Lester
140 for lots of patches.
141 This program is free software; you may redistribute it and/or modify it
143 under the same terms as Perl itself.
144 A git repository for this module is available at
146 git://github.com/rgs/Test-LongString.git
148 and the project page at
150 http://github.com/rgs/Test-LongString
152
154 Test::Builder, Test::Builder::Tester, Test::More.
155perl v5.34.0 2021-07-23 Test::LongString(3)