.\" -*- mode: troff; coding: utf-8 -*-
.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>.
.ie n \{\
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "Perl::Critic::Policy::Modules::RequireVersionVar 3pm"
.TH Perl::Critic::Policy::Modules::RequireVersionVar 3pm 2023-07-26 "perl v5.38.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH NAME
Perl::Critic::Policy::Modules::RequireVersionVar \- Give every module a "$VERSION" number.
.SH AFFILIATION
.IX Header "AFFILIATION"
This Policy is part of the core Perl::Critic
distribution.
.SH DESCRIPTION
.IX Header "DESCRIPTION"
Every Perl file (modules, libraries, and programs) should have a
package-scoped \f(CW$VERSION\fR variable.  The \f(CW$VERSION\fR allows clients to
insist on a particular revision of your file like this:
.PP
.Vb 1
\&    use SomeModule 2.4;  #Only loads version 2.4
.Ve
.PP
This Policy scans your file for any package variable named
\&\f(CW$VERSION\fR.  I'm assuming that you are using \f(CW\*(C`strict\*(C'\fR, so you'll
have to declare it like one of these:
.PP
.Vb 4
\&    our $VERSION = 1.0611;
\&    $MyPackage::VERSION = 1.061;
\&    use vars qw($VERSION);
\&    use version; our $VERSION = qv(1.0611);
.Ve
.PP
Perl's version system does not recognize lexical variables such as
.PP
.Vb 1
\&    my $VERSION = 1.0611;
.Ve
.PP
so they are not accepted by this policy.
.PP
A common practice is to use the \f(CW\*(C`$Revision$\*(C'\fR keyword to
automatically define the \f(CW$VERSION\fR variable like this:
.PP
.Vb 1
\&    our ($VERSION) = \*(Aq$Revision$\*(Aq =~ m{ \e$Revision: \es+ (\eS+) }x;
.Ve
.SH CONFIGURATION
.IX Header "CONFIGURATION"
This Policy is not configurable except for the standard options.
.SH NOTES
.IX Header "NOTES"
Conway recommends using the \f(CW\*(C`version\*(C'\fR pragma instead of raw numbers
or 'v\-strings.'  However, this Policy only insists that the
\&\f(CW$VERSION\fR be defined somehow.  I may try to extend this in the
future.
.SH "TO DO"
.IX Header "TO DO"
Add check that \f(CW$VERSION\fR is independently evaluatable.  In
particular, prohibit this:
.PP
.Vb 1
\&    our $VERSION = $Other::Module::VERSION;
.Ve
.PP
This doesn't work because PAUSE and other tools literally copy your
version declaration out of your module and evaluates it in isolation,
at which point there's nothing in \f(CW\*(C`Other::Module\*(C'\fR, and so the
\&\f(CW$VERSION\fR is undefined.
.SH AUTHOR
.IX Header "AUTHOR"
Jeffrey Ryan Thalhammer <jeff@imaginative\-software.com>
.SH COPYRIGHT
.IX Header "COPYRIGHT"
Copyright (c) 2005\-2021 Imaginative Software Systems.  All rights reserved.
.PP
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.