Test::Exception(3pm)

1Test::Exception(3)    User Contributed Perl Documentation   Test::Exception(3)
2
3
4

NAME

6       Test::Exception - Test exception based code
7

SYNOPSIS

9         use Test::More tests => 5;
10         use Test::Exception;
11
12         # or if you don't need Test::More
13
14         use Test::Exception tests => 5;
15
16         # then...
17
18         # Check that the stringified exception matches given regex
19         throws_ok { $foo->method } qr/division by zero/, 'zero caught okay';
20
21         # Check an exception of the given class (or subclass) is thrown
22         throws_ok { $foo->method } 'Error::Simple', 'simple error thrown';
23
24         # all Test::Exceptions subroutines are guaranteed to preserve the state
25         # of $@ so you can do things like this after throws_ok and dies_ok
26         like $@, 'what the stringified exception should look like';
27
28         # Check that something died - we do not care why
29         dies_ok { $foo->method } 'expecting to die';
30
31         # Check that something did not die
32         lives_ok { $foo->method } 'expecting to live';
33
34         # Check that a test runs without an exception
35         lives_and { is $foo->method, 42 } 'method is 42';
36
37         # or if you don't like prototyped functions
38
39         throws_ok( sub { $foo->method }, qr/division by zero/,
40             'zero caught okay' );
41         throws_ok( sub { $foo->method }, 'Error::Simple',
42             'simple error thrown' );
43         dies_ok( sub { $foo->method }, 'expecting to die' );
44         lives_ok( sub { $foo->method }, 'expecting to live' );
45         lives_and( sub { is $foo->method, 42 }, 'method is 42' );
46

DESCRIPTION

48       This module provides a few convenience methods for testing exception
49       based code. It is built with Test::Builder and plays happily with
50       Test::More and friends.
51
52       If you are not already familiar with Test::More now would be the time
53       to go take a look.
54
55       You can specify the test plan when you "use Test::Exception" in the
56       same way as "use Test::More".  See Test::More for details.
57
58       NOTE: Test::Exception only checks for exceptions. It will ignore other
59       methods of stopping program execution - including exit(). If you have
60       an exit() in evalled code Test::Exception will not catch this with any
61       of its testing functions.
62
63       throws_ok
64           Tests to see that a specific exception is thrown. throws_ok() has
65           two forms:
66
67             throws_ok BLOCK REGEX, TEST_DESCRIPTION
68             throws_ok BLOCK CLASS, TEST_DESCRIPTION
69
70           In the first form the test passes if the stringified exception
71           matches the give regular expression. For example:
72
73               throws_ok { read_file( 'unreadable' ) } qr/No file/, 'no file';
74
75           If your perl does not support "qr//" you can also pass a regex-like
76           string, for example:
77
78               throws_ok { read_file( 'unreadable' ) } '/No file/', 'no file';
79
80           The second form of throws_ok() test passes if the exception is of
81           the same class as the one supplied, or a subclass of that class.
82           For example:
83
84               throws_ok { $foo->bar } "Error::Simple", 'simple error';
85
86           Will only pass if the "bar" method throws an Error::Simple
87           exception, or a subclass of an Error::Simple exception.
88
89           You can get the same effect by passing an instance of the exception
90           you want to look for. The following is equivalent to the previous
91           example:
92
93               my $SIMPLE = Error::Simple->new;
94               throws_ok { $foo->bar } $SIMPLE, 'simple error';
95
96           Should a throws_ok() test fail it produces appropriate diagnostic
97           messages. For example:
98
99               not ok 3 - simple error
100               #     Failed test (test.t at line 48)
101               # expecting: Error::Simple exception
102               # found: normal exit
103
104           Like all other Test::Exception functions you can avoid prototypes
105           by passing a subroutine explicitly:
106
107               throws_ok( sub {$foo->bar}, "Error::Simple", 'simple error' );
108
109           A true value is returned if the test succeeds, false otherwise. On
110           exit $@ is guaranteed to be the cause of death (if any).
111
112           A description of the exception being checked is used if no optional
113           test description is passed.
114
115           NOTE: Rememeber when you "die $string_without_a_trailing_newline"
116           perl will automatically add the current script line number, input
117           line number and a newline. This will form part of the string that
118           throws_ok regular expressions match against.
119
120       dies_ok
121           Checks that a piece of code dies, rather than returning normally.
122           For example:
123
124               sub div {
125                   my ( $a, $b ) = @_;
126                   return $a / $b;
127               };
128
129               dies_ok { div( 1, 0 ) } 'divide by zero detected';
130
131               # or if you don't like prototypes
132               dies_ok( sub { div( 1, 0 ) }, 'divide by zero detected' );
133
134           A true value is returned if the test succeeds, false otherwise. On
135           exit $@ is guaranteed to be the cause of death (if any).
136
137           Remember: This test will pass if the code dies for any reason. If
138           you care about the reason it might be more sensible to write a more
139           specific test using throws_ok().
140
141           The test description is optional, but recommended.
142
143       lives_ok
144           Checks that a piece of code doesn't die. This allows your test
145           script to continue, rather than aborting if you get an unexpected
146           exception. For example:
147
148               sub read_file {
149                   my $file = shift;
150                   local $/;
151                   open my $fh, '<', $file or die "open failed ($!)\n";
152                   $file = <FILE>;
153                   return $file;
154               };
155
156               my $file;
157               lives_ok { $file = read_file('test.txt') } 'file read';
158
159               # or if you don't like prototypes
160               lives_ok( sub { $file = read_file('test.txt') }, 'file read' );
161
162           Should a lives_ok() test fail it produces appropriate diagnostic
163           messages. For example:
164
165               not ok 1 - file read
166               #     Failed test (test.t at line 15)
167               # died: open failed (No such file or directory)
168
169           A true value is returned if the test succeeds, false otherwise. On
170           exit $@ is guaranteed to be the cause of death (if any).
171
172           The test description is optional, but recommended.
173
174       lives_and
175           Run a test that may throw an exception. For example, instead of
176           doing:
177
178             my $file;
179             lives_ok { $file = read_file('answer.txt') } 'read_file worked';
180             is $file, "42", 'answer was 42';
181
182           You can use lives_and() like this:
183
184             lives_and { is read_file('answer.txt'), "42" } 'answer is 42';
185             # or if you don't like prototypes
186             lives_and(sub {is read_file('answer.txt'), "42"}, 'answer is 42');
187
188           Which is the same as doing
189
190             is read_file('answer.txt'), "42\n", 'answer is 42';
191
192           unless "read_file('answer.txt')" dies, in which case you get the
193           same kind of error as lives_ok()
194
195             not ok 1 - answer is 42
196             #     Failed test (test.t at line 15)
197             # died: open failed (No such file or directory)
198
199           A true value is returned if the test succeeds, false otherwise. On
200           exit $@ is guaranteed to be the cause of death (if any).
201
202           The test description is optional, but recommended.
203

SKIPPING TEST::EXCEPTION TESTS

205       Sometimes we want to use Test::Exception tests in a test suite, but
206       don't want to force the user to have Test::Exception installed. One way
207       to do this is to skip the tests if Test::Exception is absent. You can
208       do this with code something like this:
209
210         use strict;
211         use warnings;
212         use Test::More;
213
214         BEGIN {
215             eval "use Test::Exception";
216             plan skip_all => "Test::Exception needed" if $@;
217         }
218
219         plan tests => 2;
220         # ... tests that need Test::Exception ...
221
222       Note that we load Test::Exception in a "BEGIN" block ensuring that the
223       subroutine prototypes are in place before the rest of the test script
224       is compiled.
225

BUGS

227       There are some edge cases in Perl's exception handling where
228       Test::Exception will miss exceptions thrown in DESTROY blocks. See the
229       RT bug <http://rt.cpan.org/Ticket/Display.html?id=24678> for details,
230       along with the t/edge-cases.t in the distribution test suite. These
231       will be addressed in a future Test::Exception release.
232
233       If you find any more bugs please let me know by e-mail, or report the
234       problem with <http://rt.cpan.org/>.
235

COMMUNITY

237       perl-qa
238           If you are interested in testing using Perl I recommend you visit
239           <http://qa.perl.org/> and join the excellent perl-qa mailing list.
240           See <http://lists.perl.org/showlist.cgi?name=perl-qa> for details
241           on how to subscribe.
242
243       perlmonks
244           You can find users of Test::Exception, including the module author,
245           on  <http://www.perlmonks.org/>. Feel free to ask questions on
246           Test::Exception there.
247
248       CPAN::Forum
249           The CPAN Forum is a web forum for discussing Perl's CPAN modules.
250           The Test::Exception forum can be found at
251           <http://www.cpanforum.com/dist/Test-Exception>.
252
253       AnnoCPAN
254           AnnoCPAN is a web site that allows community annotations of Perl
255           module documentation. The Test::Exception annotations can be found
256           at <http://annocpan.org/~ADIE/Test-Exception/>.
257

TO DO

259       If you think this module should do something that it doesn't (or does
260       something that it shouldn't) please let me know.
261
262       You can see my current to do list at
263       <http://adrianh.tadalist.com/lists/public/15421>, with an RSS feed of
264       changes at <http://adrianh.tadalist.com/lists/feed_public/15421>.
265

ACKNOWLEDGMENTS

267       Thanks to chromatic and Michael G Schwern for the excellent
268       Test::Builder, without which this module wouldn't be possible.
269
270       Thanks to Adam Kennedy, Andy Lester, Aristotle Pagaltzis, Ben Prew,
271       Cees Hek, Chris Dolan, chromatic, Curt Sampson, David Cantrell, David
272       Golden, David Tulloh, David Wheeler, J. K. O'Brien, Janek Schleicher,
273       Jim Keenan, Jos I. Boumans, Joshua ben Jore, Jost Krieger, Mark Fowler,
274       Michael G Schwern, Nadim Khemir, Paul McCann, Perrin Harkins, Peter
275       Rabbitson, Peter Scott, Ricardo Signes, Rob Muhlestein, Scott R. Godin,
276       Steve Purkis, Steve, Tim Bunce, and various anonymous folk for
277       comments, suggestions, bug reports and patches.
278

AUTHOR

280       Adrian Howard <adrianh@quietstars.com>
281
282       If you can spare the time, please drop me a line if you find this
283       module useful.
284

LICENCE

305       Copyright 2002-2007 Adrian Howard, All Rights Reserved.
306
307       This program is free software; you can redistribute it and/or modify it
308       under the same terms as Perl itself.
309
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312perl v5.16.3                      2014-06-10                Test::Exception(3)