Perl::Critic::Policy::Modules::RequireVersionVar(3pm)
                                           User Contributed Perl Documentation


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) 2005-2021 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 v5.38.0                      2023-07-26
                         Perl::Critic::Policy::Modules::RequireVersionVar(3pm)