4 use warnings FATAL => 'all';
6 use constant _PERL_LT_5_8_4 => ($] < 5.008004) ? 1 : 0;
8 our $VERSION = '1.004001'; # 1.4.1
12 last unless defined && !ref && int != 1;
13 die "Major version specified as $_ - this is strictures version 1";
15 # disable this since Foo->VERSION(undef) correctly returns the version
16 # and that can happen either if our caller passes undef explicitly or
17 # because the for above autovivified $_[1] - I could make it stop but
18 # it's pointless since we don't want to blow up if the caller does
19 # something valid either.
20 no warnings 'uninitialized';
21 shift->SUPER::VERSION(@_);
24 my $extras_load_warned;
26 our $Smells_Like_VCS = (-e '.git' || -e '.svn'
27 || (-e '../../dist.ini' && (-e '../../.git' || -e '../../.svn')));
31 warnings->import(FATAL => 'all');
33 my $extra_tests = do {
34 if (exists $ENV{PERL_STRICTURES_EXTRA}) {
35 if (_PERL_LT_5_8_4 and $ENV{PERL_STRICTURES_EXTRA}) {
36 die 'PERL_STRICTURES_EXTRA checks are not available on perls older than 5.8.4: '
37 . "please unset \$ENV{PERL_STRICTURES_EXTRA}\n";
39 $ENV{PERL_STRICTURES_EXTRA};
40 } elsif (! _PERL_LT_5_8_4) {
41 !!((caller)[1] =~ /^(?:t|xt|lib|blib)/
47 if (eval { require indirect; 1 }) {
48 indirect->unimport(':fatal');
50 push @failed, 'indirect';
52 if (eval { require multidimensional; 1 }) {
53 multidimensional->unimport;
55 push @failed, 'multidimensional';
57 if (eval { require bareword::filehandles; 1 }) {
58 bareword::filehandles->unimport;
60 push @failed, 'bareword::filehandles';
62 if (@failed and not $extras_load_warned++) {
63 my $failed = join ' ', @failed;
65 strictures.pm extra testing active but couldn't load all modules. Missing were:
69 Extra testing is auto-enabled in checkouts only, so if you're the author
70 of a strictures using module you need to run:
72 cpan indirect multidimensional bareword::filehandles
74 but these modules are not required by your users.
85 strictures - turn on strict and make all warnings fatal
94 use warnings FATAL => 'all';
96 except when called from a file which matches:
98 (caller)[1] =~ /^(?:t|xt|lib|blib)/
100 and when either C<.git> or C<.svn> is present in the current directory (with
101 the intention of only forcing extra tests on the author side) -- or when C<.git>
102 or C<.svn> is present two directories up along with C<dist.ini> (which would
103 indicate we are in a C<dzil test> operation, via L<Dist::Zilla>) --
104 or when the C<PERL_STRICTURES_EXTRA> environment variable is set, in which case
111 use warnings FATAL => 'all';
114 no bareword::filehandles;
116 Note that C<PERL_STRICTURES_EXTRA> may at some point add even more tests, with only a minor
117 version increase, but any changes to the effect of C<use strictures> in
118 normal mode will involve a major version bump.
120 If any of the extra testing modules are not present, L<strictures> will
121 complain loudly, once, via C<warn()>, and then shut up. But you really
122 should consider installing them, they're all great anti-footgun tools.
126 I've been writing the equivalent of this module at the top of my code for
127 about a year now. I figured it was time to make it shorter.
129 Things like the importer in C<use Moose> don't help me because they turn
130 warnings on but don't make them fatal -- which from my point of view is
131 useless because I want an exception to tell me my code isn't warnings-clean.
133 Any time I see a warning from my code, that indicates a mistake.
135 Any time my code encounters a mistake, I want a crash -- not spew to STDERR
136 and then unknown (and probably undesired) subsequent behaviour.
138 I also want to ensure that obvious coding mistakes, like indirect object
139 syntax (and not so obvious mistakes that cause things to accidentally compile
140 as such) get caught, but not at the cost of an XS dependency and not at the
141 cost of blowing things up on another machine.
143 Therefore, L<strictures> turns on additional checking, but only when it thinks
144 it's running in a test file in a VCS checkout -- although if this causes
145 undesired behaviour this can be overridden by setting the
146 C<PERL_STRICTURES_EXTRA> environment variable.
148 If additional useful author side checks come to mind, I'll add them to the
149 C<PERL_STRICTURES_EXTRA> code path only -- this will result in a minor version increase (e.g.
150 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the mechanism of
151 this code will result in a sub-version increase (e.g. 1.000000 to 1.000001
154 If the behaviour of C<use strictures> in normal mode changes in any way, that
155 will constitute a major version increase -- and the code already checks
156 when its version is tested to ensure that
160 will continue to only introduce the current set of strictures even if 2.0 is
167 This method does the setup work described above in L</DESCRIPTION>
171 This method traps the C<< strictures->VERSION(1) >> call produced by a use line
172 with a version number on it and does the version check.
174 =head1 EXTRA TESTING RATIONALE
176 Every so often, somebody complains that they're deploying via C<git pull>
177 and that they don't want L<strictures> to enable itself in this case -- and that
178 setting C<PERL_STRICTURES_EXTRA> to 0 isn't acceptable (additional ways to
179 disable extra testing would be welcome but the discussion never seems to get
182 In order to allow us to skip a couple of stages and get straight to a
183 productive conversation, here's my current rationale for turning the
184 extra testing on via a heuristic:
186 The extra testing is all stuff that only ever blows up at compile time;
187 this is intentional. So the oft-raised concern that it's different code being
188 tested is only sort of the case -- none of the modules involved affect the
189 final optree to my knowledge, so the author gets some additional compile
190 time crashes which he/she then fixes, and the rest of the testing is
191 completely valid for all environments.
193 The point of the extra testing -- especially C<no indirect> -- is to catch
194 mistakes that newbie users won't even realise are mistakes without
199 where foo is an & prototyped sub that you forgot to import -- this is
200 pernicious to track down since all I<seems> fine until it gets called
201 and you get a crash. Worse still, you can fail to have imported it due
202 to a circular require, at which point you have a load order dependent
203 bug which I've seen before now I<only> show up in production due to tiny
204 differences between the production and the development environment. I wrote
205 L<http://shadow.cat/blog/matt-s-trout/indirect-but-still-fatal/> to explain
206 this particular problem before L<strictures> itself existed.
208 As such, in my experience so far L<strictures>' extra testing has
209 I<avoided> production versus development differences, not caused them.
211 Additionally, L<strictures>' policy is very much "try and provide as much
212 protection as possible for newbies -- who won't think about whether there's
213 an option to turn on or not" -- so having only the environment variable
214 is not sufficient to achieve that (I get to explain that you need to add
215 C<use strict> at least once a week on freenode #perl -- newbies sometimes
216 completely skip steps because they don't understand that that step
219 I make no claims that the heuristic is perfect -- it's already been evolved
220 significantly over time, especially for 1.004 where we changed things to
221 ensure it only fires on files in your checkout (rather than L<strictures>-using
222 modules you happened to have installed, which was just silly). However, I
223 hope the above clarifies why a heuristic approach is not only necessary but
224 desirable from a point of view of providing new users with as much safety as possible,
225 and will allow any future discussion on the subject to focus on "how do we
226 minimise annoyance to people deploying from checkouts intentionally".
228 =head1 COMMUNITY AND SUPPORT
232 irc.perl.org #toolchain
234 (or bug 'mst' in query on there or freenode)
236 =head2 Git repository
238 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
240 git clone git://git.shadowcat.co.uk/p5sagit/strictures.git
242 The web interface to the repository is at:
244 http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git
248 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
252 None required yet. Maybe this module is perfect (hahahahaha ...).
256 Copyright (c) 2010 the strictures L</AUTHOR> and L</CONTRIBUTORS>
261 This library is free software and may be distributed under the same terms