4 use warnings FATAL => 'all';
6 use constant _PERL_LT_5_8_4 => ($] < 5.008004) ? 1 : 0;
8 our $VERSION = '1.004003'; # 1.4.3
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 $extra_load_states;
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)/
46 $extra_load_states ||= do {
49 for my $mod (qw(indirect multidimensional bareword::filehandles)) {
50 eval "require $mod; \$rv{'$mod'} = 1;" or do {
53 # courtesy of the 5.8 require bug
55 delete $INC{"$mod.pm"};
60 my $failed = join ' ', @failed;
62 strictures.pm extra testing active but couldn't load all modules. Missing were:
66 Extra testing is auto-enabled in checkouts only, so if you're the author
67 of a strictures-using module you need to run:
69 cpan indirect multidimensional bareword::filehandles
71 but these modules are not required by your users.
78 indirect->unimport(':fatal') if $extra_load_states->{indirect};
79 multidimensional->unimport if $extra_load_states->{multidimensional};
80 bareword::filehandles->unimport if $extra_load_states->{'bareword::filehandles'};
89 strictures - turn on strict and make all warnings fatal
98 use warnings FATAL => 'all';
100 except when called from a file which matches:
102 (caller)[1] =~ /^(?:t|xt|lib|blib)/
104 and when either C<.git> or C<.svn> is present in the current directory (with
105 the intention of only forcing extra tests on the author side) -- or when C<.git>
106 or C<.svn> is present two directories up along with C<dist.ini> (which would
107 indicate we are in a C<dzil test> operation, via L<Dist::Zilla>) --
108 or when the C<PERL_STRICTURES_EXTRA> environment variable is set, in which case
115 use warnings FATAL => 'all';
118 no bareword::filehandles;
120 Note that C<PERL_STRICTURES_EXTRA> may at some point add even more tests, with only a minor
121 version increase, but any changes to the effect of C<use strictures> in
122 normal mode will involve a major version bump.
124 If any of the extra testing modules are not present, L<strictures> will
125 complain loudly, once, via C<warn()>, and then shut up. But you really
126 should consider installing them, they're all great anti-footgun tools.
130 I've been writing the equivalent of this module at the top of my code for
131 about a year now. I figured it was time to make it shorter.
133 Things like the importer in C<use Moose> don't help me because they turn
134 warnings on but don't make them fatal -- which from my point of view is
135 useless because I want an exception to tell me my code isn't warnings-clean.
137 Any time I see a warning from my code, that indicates a mistake.
139 Any time my code encounters a mistake, I want a crash -- not spew to STDERR
140 and then unknown (and probably undesired) subsequent behaviour.
142 I also want to ensure that obvious coding mistakes, like indirect object
143 syntax (and not so obvious mistakes that cause things to accidentally compile
144 as such) get caught, but not at the cost of an XS dependency and not at the
145 cost of blowing things up on another machine.
147 Therefore, L<strictures> turns on additional checking, but only when it thinks
148 it's running in a test file in a VCS checkout -- although if this causes
149 undesired behaviour this can be overridden by setting the
150 C<PERL_STRICTURES_EXTRA> environment variable.
152 If additional useful author side checks come to mind, I'll add them to the
153 C<PERL_STRICTURES_EXTRA> code path only -- this will result in a minor version increase (e.g.
154 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the mechanism of
155 this code will result in a sub-version increase (e.g. 1.000000 to 1.000001
158 If the behaviour of C<use strictures> in normal mode changes in any way, that
159 will constitute a major version increase -- and the code already checks
160 when its version is tested to ensure that
164 will continue to only introduce the current set of strictures even if 2.0 is
171 This method does the setup work described above in L</DESCRIPTION>
175 This method traps the C<< strictures->VERSION(1) >> call produced by a use line
176 with a version number on it and does the version check.
178 =head1 EXTRA TESTING RATIONALE
180 Every so often, somebody complains that they're deploying via C<git pull>
181 and that they don't want L<strictures> to enable itself in this case -- and that
182 setting C<PERL_STRICTURES_EXTRA> to 0 isn't acceptable (additional ways to
183 disable extra testing would be welcome but the discussion never seems to get
186 In order to allow us to skip a couple of stages and get straight to a
187 productive conversation, here's my current rationale for turning the
188 extra testing on via a heuristic:
190 The extra testing is all stuff that only ever blows up at compile time;
191 this is intentional. So the oft-raised concern that it's different code being
192 tested is only sort of the case -- none of the modules involved affect the
193 final optree to my knowledge, so the author gets some additional compile
194 time crashes which he/she then fixes, and the rest of the testing is
195 completely valid for all environments.
197 The point of the extra testing -- especially C<no indirect> -- is to catch
198 mistakes that newbie users won't even realise are mistakes without
203 where foo is an & prototyped sub that you forgot to import -- this is
204 pernicious to track down since all I<seems> fine until it gets called
205 and you get a crash. Worse still, you can fail to have imported it due
206 to a circular require, at which point you have a load order dependent
207 bug which I've seen before now I<only> show up in production due to tiny
208 differences between the production and the development environment. I wrote
209 L<http://shadow.cat/blog/matt-s-trout/indirect-but-still-fatal/> to explain
210 this particular problem before L<strictures> itself existed.
212 As such, in my experience so far L<strictures>' extra testing has
213 I<avoided> production versus development differences, not caused them.
215 Additionally, L<strictures>' policy is very much "try and provide as much
216 protection as possible for newbies -- who won't think about whether there's
217 an option to turn on or not" -- so having only the environment variable
218 is not sufficient to achieve that (I get to explain that you need to add
219 C<use strict> at least once a week on freenode #perl -- newbies sometimes
220 completely skip steps because they don't understand that that step
223 I make no claims that the heuristic is perfect -- it's already been evolved
224 significantly over time, especially for 1.004 where we changed things to
225 ensure it only fires on files in your checkout (rather than L<strictures>-using
226 modules you happened to have installed, which was just silly). However, I
227 hope the above clarifies why a heuristic approach is not only necessary but
228 desirable from a point of view of providing new users with as much safety as possible,
229 and will allow any future discussion on the subject to focus on "how do we
230 minimise annoyance to people deploying from checkouts intentionally".
232 =head1 COMMUNITY AND SUPPORT
236 irc.perl.org #toolchain
238 (or bug 'mst' in query on there or freenode)
240 =head2 Git repository
242 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
244 git clone git://git.shadowcat.co.uk/p5sagit/strictures.git
246 The web interface to the repository is at:
248 http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git
252 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
256 None required yet. Maybe this module is perfect (hahahahaha ...).
260 Copyright (c) 2010 the strictures L</AUTHOR> and L</CONTRIBUTORS>
265 This library is free software and may be distributed under the same terms