4 use warnings FATAL => 'all';
7 *_PERL_LT_5_8_4 = ($] < 5.008004) ? sub(){1} : sub(){0};
10 our $VERSION = '1.005001'; # 1.5.1
14 last unless defined && !ref && int != 1;
15 die "Major version specified as $_ - this is strictures version 1";
17 # disable this since Foo->VERSION(undef) correctly returns the version
18 # and that can happen either if our caller passes undef explicitly or
19 # because the for above autovivified $_[1] - I could make it stop but
20 # it's pointless since we don't want to blow up if the caller does
21 # something valid either.
22 no warnings 'uninitialized';
23 shift->SUPER::VERSION(@_);
26 our $extra_load_states;
28 our $Smells_Like_VCS = (-e '.git' || -e '.svn' || -e '.hg'
29 || (-e '../../dist.ini'
30 && (-e '../../.git' || -e '../../.svn' || -e '../../.hg' )));
34 warnings->import(FATAL => 'all');
36 my $extra_tests = do {
37 if (exists $ENV{PERL_STRICTURES_EXTRA}) {
38 if (_PERL_LT_5_8_4 and $ENV{PERL_STRICTURES_EXTRA}) {
39 die 'PERL_STRICTURES_EXTRA checks are not available on perls older than 5.8.4: '
40 . "please unset \$ENV{PERL_STRICTURES_EXTRA}\n";
42 $ENV{PERL_STRICTURES_EXTRA};
43 } elsif (! _PERL_LT_5_8_4) {
44 !!((caller)[1] =~ /^(?:t|xt|lib|blib)/
49 $extra_load_states ||= do {
52 foreach my $mod (qw(indirect multidimensional bareword::filehandles)) {
53 eval "require $mod; \$rv{'$mod'} = 1;" or do {
56 # courtesy of the 5.8 require bug
57 # (we do a copy because 5.16.2 at least uses the same read-only
58 # scalars for the qw() list and it doesn't seem worth a $^V check)
60 (my $file = $mod) =~ s|::|/|g;
61 delete $INC{"${file}.pm"};
66 my $failed = join ' ', @failed;
68 strictures.pm extra testing active but couldn't load all modules. Missing were:
72 Extra testing is auto-enabled in checkouts only, so if you're the author
73 of a strictures-using module you need to run:
75 cpan indirect multidimensional bareword::filehandles
77 but these modules are not required by your users.
84 indirect->unimport(':fatal') if $extra_load_states->{indirect};
85 multidimensional->unimport if $extra_load_states->{multidimensional};
86 bareword::filehandles->unimport if $extra_load_states->{'bareword::filehandles'};
95 strictures - turn on strict and make all warnings fatal
104 use warnings FATAL => 'all';
106 except when called from a file which matches:
108 (caller)[1] =~ /^(?:t|xt|lib|blib)/
110 and when either C<.git>, C<.svn>, or C<.hg> is present in the current directory (with
111 the intention of only forcing extra tests on the author side) -- or when C<.git>,
112 C<.svn>, or C<.hg> is present two directories up along with C<dist.ini> (which would
113 indicate we are in a C<dzil test> operation, via L<Dist::Zilla>) --
114 or when the C<PERL_STRICTURES_EXTRA> environment variable is set, in which case
121 use warnings FATAL => 'all';
124 no bareword::filehandles;
126 Note that C<PERL_STRICTURES_EXTRA> may at some point add even more tests, with only a minor
127 version increase, but any changes to the effect of C<use strictures> in
128 normal mode will involve a major version bump.
130 If any of the extra testing modules are not present, L<strictures> will
131 complain loudly, once, via C<warn()>, and then shut up. But you really
132 should consider installing them, they're all great anti-footgun tools.
136 I've been writing the equivalent of this module at the top of my code for
137 about a year now. I figured it was time to make it shorter.
139 Things like the importer in C<use Moose> don't help me because they turn
140 warnings on but don't make them fatal -- which from my point of view is
141 useless because I want an exception to tell me my code isn't warnings-clean.
143 Any time I see a warning from my code, that indicates a mistake.
145 Any time my code encounters a mistake, I want a crash -- not spew to STDERR
146 and then unknown (and probably undesired) subsequent behaviour.
148 I also want to ensure that obvious coding mistakes, like indirect object
149 syntax (and not so obvious mistakes that cause things to accidentally compile
150 as such) get caught, but not at the cost of an XS dependency and not at the
151 cost of blowing things up on another machine.
153 Therefore, L<strictures> turns on additional checking, but only when it thinks
154 it's running in a test file in a VCS checkout -- although if this causes
155 undesired behaviour this can be overridden by setting the
156 C<PERL_STRICTURES_EXTRA> environment variable.
158 If additional useful author side checks come to mind, I'll add them to the
159 C<PERL_STRICTURES_EXTRA> code path only -- this will result in a minor version increase (e.g.
160 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the mechanism of
161 this code will result in a sub-version increase (e.g. 1.000000 to 1.000001
164 If the behaviour of C<use strictures> in normal mode changes in any way, that
165 will constitute a major version increase -- and the code already checks
166 when its version is tested to ensure that
170 will continue to only introduce the current set of strictures even if 2.0 is
177 This method does the setup work described above in L</DESCRIPTION>
181 This method traps the C<< strictures->VERSION(1) >> call produced by a use line
182 with a version number on it and does the version check.
184 =head1 EXTRA TESTING RATIONALE
186 Every so often, somebody complains that they're deploying via C<git pull>
187 and that they don't want L<strictures> to enable itself in this case -- and that
188 setting C<PERL_STRICTURES_EXTRA> to 0 isn't acceptable (additional ways to
189 disable extra testing would be welcome but the discussion never seems to get
192 In order to allow us to skip a couple of stages and get straight to a
193 productive conversation, here's my current rationale for turning the
194 extra testing on via a heuristic:
196 The extra testing is all stuff that only ever blows up at compile time;
197 this is intentional. So the oft-raised concern that it's different code being
198 tested is only sort of the case -- none of the modules involved affect the
199 final optree to my knowledge, so the author gets some additional compile
200 time crashes which he/she then fixes, and the rest of the testing is
201 completely valid for all environments.
203 The point of the extra testing -- especially C<no indirect> -- is to catch
204 mistakes that newbie users won't even realise are mistakes without
209 where foo is an & prototyped sub that you forgot to import -- this is
210 pernicious to track down since all I<seems> fine until it gets called
211 and you get a crash. Worse still, you can fail to have imported it due
212 to a circular require, at which point you have a load order dependent
213 bug which I've seen before now I<only> show up in production due to tiny
214 differences between the production and the development environment. I wrote
215 L<http://shadow.cat/blog/matt-s-trout/indirect-but-still-fatal/> to explain
216 this particular problem before L<strictures> itself existed.
218 As such, in my experience so far L<strictures>' extra testing has
219 I<avoided> production versus development differences, not caused them.
221 Additionally, L<strictures>' policy is very much "try and provide as much
222 protection as possible for newbies -- who won't think about whether there's
223 an option to turn on or not" -- so having only the environment variable
224 is not sufficient to achieve that (I get to explain that you need to add
225 C<use strict> at least once a week on freenode #perl -- newbies sometimes
226 completely skip steps because they don't understand that that step
229 I make no claims that the heuristic is perfect -- it's already been evolved
230 significantly over time, especially for 1.004 where we changed things to
231 ensure it only fires on files in your checkout (rather than L<strictures>-using
232 modules you happened to have installed, which was just silly). However, I
233 hope the above clarifies why a heuristic approach is not only necessary but
234 desirable from a point of view of providing new users with as much safety as possible,
235 and will allow any future discussion on the subject to focus on "how do we
236 minimise annoyance to people deploying from checkouts intentionally".
252 L<bareword::filehandles>
256 =head1 COMMUNITY AND SUPPORT
260 irc.perl.org #toolchain
262 (or bug 'mst' in query on there or freenode)
264 =head2 Git repository
266 Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
268 git clone git://git.shadowcat.co.uk/p5sagit/strictures.git
270 The web interface to the repository is at:
272 http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git
276 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
280 Karen Etheridge (cpan:ETHER) <ether@cpan.org>
282 Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@gmail.com>
284 haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org>
288 Copyright (c) 2010 the strictures L</AUTHOR> and L</CONTRIBUTORS>
293 This library is free software and may be distributed under the same terms