Perl::Critic::Policy::Modules::ProhibitAutomaticExportation - Export symbols via C<@EXPORT_OK> or C<%EXPORT_TAGS> instead of C<@EXPORT>.

Perl-Critic documentation Contained in the Perl-Critic distribution.

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NAME

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Perl::Critic::Policy::Modules::ProhibitAutomaticExportation - Export symbols via @EXPORT_OK or %EXPORT_TAGS instead of @EXPORT.

AFFILIATION

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

DESCRIPTION

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When using Exporter, symbols placed in the @EXPORT variable are automatically exported into the caller's namespace. Although convenient, this practice is not polite, and may cause serious problems if the caller declares the same symbols. The best practice is to place your symbols in @EXPORT_OK or %EXPORT_TAGS and let the caller choose exactly which symbols to export.

    package Foo;

    use base qw(Exporter);
    our @EXPORT      = qw(foo $bar @baz);                  # not ok
    our @EXPORT_OK   = qw(foo $bar @baz);                  # ok
    our %EXPORT_TAGS = ( all => [ qw(foo $bar @baz) ] );   # ok

CONFIGURATION

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This Policy is not configurable except for the standard options.

AUTHOR

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

COPYRIGHT

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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-Critic documentation Contained in the Perl-Critic distribution. 
##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/Policy/Modules/ProhibitAutomaticExportation.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::Policy::Modules::ProhibitAutomaticExportation;

use 5.006001;
use strict;
use warnings;
use Readonly;

use Perl::Critic::Utils qw{ :severities };
use List::MoreUtils qw(any);
use base 'Perl::Critic::Policy';

our $VERSION = '1.116';

#-----------------------------------------------------------------------------

Readonly::Scalar my $DESC => q{Symbols are exported by default};
Readonly::Scalar my $EXPL => q{Use '@EXPORT_OK' or '%EXPORT_TAGS' instead};  ## no critic (RequireInterpolation)

#-----------------------------------------------------------------------------

sub supported_parameters { return ()              }
sub default_severity     { return $SEVERITY_HIGH  }
sub default_themes       { return qw( core bugs ) }
sub applies_to           { return 'PPI::Document' }

#-----------------------------------------------------------------------------

sub violates {
    my ( $self, $elem, $doc ) = @_;

    if ( _uses_exporter($doc) ) {
        if ( my $exp = _has_exports($doc) ) {
            return $self->violation( $DESC, $EXPL, $exp );
        }
    }
    return; #ok
}

#-----------------------------------------------------------------------------

sub _uses_exporter {
    my ($doc) = @_;

    my $includes_ref = $doc->find('PPI::Statement::Include');
    return if not $includes_ref;

    # This covers both C<use Exporter;> and C<use base 'Exporter';>
    return scalar grep { m/ \b Exporter \b/xms }  @{ $includes_ref };
}

#------------------

sub _has_exports {
    my ($doc) = @_;

    my $wanted =
        sub { _our_export(@_) or _vars_export(@_) or _package_export(@_) };

    return $doc->find_first( $wanted );
}

#------------------

sub _our_export {
    my (undef, $elem) = @_;

    $elem->isa('PPI::Statement::Variable') or return 0;
    $elem->type() eq 'our' or return 0;

    return any { $_ eq '@EXPORT' } $elem->variables(); ## no critic(RequireInterpolationOfMetachars)
}

#------------------

sub _vars_export {
    my (undef, $elem) = @_;

    $elem->isa('PPI::Statement::Include') or return 0;
    $elem->pragma() eq 'vars' or return 0;

    return $elem =~ m{ \@EXPORT \b }xms; #Crude, but usually works
}

#------------------

sub _package_export {
    my (undef, $elem) = @_;

    $elem->isa('PPI::Token::Symbol') or return 0;

    return $elem =~ m{ \A \@ \S+ ::EXPORT \z }xms;
    #TODO: ensure that it is in _this_ package!
}

1;

__END__

#-----------------------------------------------------------------------------


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