NAME¶
Perl::Critic::Policy::ValuesAndExpressions::ProhibitComplexVersion - Prohibit
version values from outside the module.
AFFILIATION¶
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION¶
One tempting way to keep a group of related modules at the same version number
is to have all of them import the version number from a designated module. For
example, module "Foo::Master" could be the version master for the
"Foo" package, and all other modules could use its $VERSION by
use Foo::Master; our $VERSION = $Foo::Master::VERSION;
This turns out not to be a good idea, because all sorts of unintended things can
happen - anything from unintended version number changes to denial-of-service
attacks (since "Foo::Master" is executed by the 'use').
This policy examines statements that assign to $VERSION, and declares a
violation under two circumstances: first, if that statement uses a
fully-qualified symbol that did not originate in a package declared in the
file; second if there is a "use" statement on the same line that
makes the assignment.
By default, an exception is made for "use version;" because of its
recommendation by Perl Best Practices. See the "forbid_use_version"
configuration variable if you do not want an exception made for "use
version;".
CONFIGURATION¶
The construction
use version; our $VERSION = qv('1.2.3');
is exempt from this policy by default, because it is recommended by Perl Best
Practices. Should you wish to identify "use version;" as a
violation, add the following to your perlcriticrc file:
[ValuesAndExpressions::ProhibitComplexVersion]
forbid_use_version = 1
CAVEATS¶
This code assumes that the hallmark of a violation is a 'use' on the same line
as the $VERSION assignment, because that is the way to have it seen by
ExtUtils::MakeMaker->
parse_version(). Other ways to get a version
value from outside the module can be imagined, and this policy is currently
oblivious to them.
AUTHOR¶
Thomas R. Wyant, III
wyant at cpan dot org
COPYRIGHT¶
Copyright (c) 2009-2011 Tom Wyant.
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.