first version of strictures.pm - code and brief docs

[p5sagit/strictures.git] / lib / strictures.pm

package strictures;

use strict;
use warnings FATAL => 'all';

our $VERSION = '1.000000'; # 1.0.0

sub VERSION {
  for ($_[1]) {
    last unless defined && !ref && int != 1;
    die "Major version specified as $_ - this is strictures version 1";
  }
  shift->SUPER::VERSION(@_);
}

sub import {
  strict->import;
  warnings->import(FATAL => 'all');
  my $do_indirect = do {
    if (exists $ENV{PERL_STRICTURES_EXTRA}) {
      $ENV{PERL_STRICTURES_EXTRA}
    } else {
      !!($0 =~ /^x?t\/.*(?:load|compile|coverage).*\.t$/)
    }
  };
  if ($do_indirect) {
    if (eval { require indirect; 1 }) {
      indirect->unimport('FATAL');
    } else {
      die "strictures.pm extra testing active but couldn't load indirect.pm: $@";
    }
  }
}

1;

__END__
=head1 NAME

strictures - turn on strict and make all warnings fatal

=head1 SYNOPSIS

  use strictures 1;

is equivalent to

  use strict;
  use warnings FATAL => 'all';

except when called from a file where $0 matches:

  /^x?t\/.*(?:load|compile|coverage).*\.t$/

or when the PERL_STRICTURES_EXTRA environment variable is set, in which
case

  use strictures 1;

is equivalent to

  use strict;
  use warnings FATAL => 'all';
  no indirect 'fatal';

Note that _EXTRA may at some point add even more tests, with only a minor
version increase, but any changes to the effect of 'use strictures' in
normal mode will involve a major version bump.

=head1 DESCRIPTION

I've been writing the equivalent of this module at the top of my code for
about a year now. I figured it was time to make it shorter.

Things like the importer in 'use Moose' don't help me because they turn
warnings on but don't make them fatal - which from my point of view is
useless because I want an exception to tell me my code isn't warnings clean.

Any time I see a warning from my code, that indicates a mistake.

Any time my code encounters a mistake, I want a crash - not spew to STDERR
and then unknown (and probably undesired) subsequent behaviour.

I also want to ensure that obvious coding mistakes, like indirect object
syntax (and not so obvious mistakes that cause things to accidentally compile
as such) get caught, but not at the cost of an XS dependency and not at the
cost of blowing things up on another machine.

Therefore, strictures turns on indirect checking only when it thinks it's
running in a compilation (or pod coverage) test - though if this causes
undesired behaviour this can be overriden by setting the
PERL_STRICTURES_EXTRA environment variable.

If additional useful author side checks come to mind, I'll add them to the
_EXTRA code path only - this will result in a minor version increase (i.e.
1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the mechanism of
this code will result in a subversion increas (i.e. 1.000000 to 1.000001
(1.0.1)).

If the behaviour of 'use strictures' in normal mode changes in any way, that
will constitute a major version increase - and the code already checks
when its version is tested to ensure that

  use strictures 1;

will continue to only introduce the current set of strictures even if 2.0 is
installed.