NAME

       Perl::Critic::Policy::Modules::RequireVersionVar - Give every module a "$VERSION" number.

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

       Every Perl file (modules, libraries, and programs) should have a package-scoped $VERSION
       variable.  The $VERSION allows clients to insist on a particular revision of your file
       like this:

           use SomeModule 2.4;  #Only loads version 2.4

       This Policy scans your file for any package variable named $VERSION.  I'm assuming that
       you are using "strict", so you'll have to declare it like one of these:

           our $VERSION = 1.0611;
           $MyPackage::VERSION = 1.061;
           use vars qw($VERSION);
           use version; our $VERSION = qv(1.0611);

       Perl's version system does not recognize lexical variables such as

           my $VERSION = 1.0611;

       so they are not accepted by this policy.

       A common practice is to use the "$Revision$" keyword to automatically define the $VERSION
       variable like this:

           our ($VERSION) = '$Revision$' =~ m{ \$Revision: \s+ (\S+) }x;

CONFIGURATION

       This Policy is not configurable except for the standard options.

NOTES

       Conway recommends using the "version" pragma instead of raw numbers or 'v-strings.'
       However, this Policy only insists that the $VERSION be defined somehow.  I may try to
       extend this in the future.

TO DO

       Add check that $VERSION is independently evaluatable.  In particular, prohibit this:

           our $VERSION = $Other::Module::VERSION;

       This doesn't work because PAUSE and other tools literally copy your version declaration
       out of your module and evaluates it in isolation, at which point there's nothing in
       "Other::Module", and so the $VERSION is undefined.

AUTHOR

       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  The full text of this license can be found in the LICENSE file
       included with this module.

perl v5.20.2                                Perl::Critic::Policy::Modules::RequireVersionVar(3pm)