File Coverage

blib/lib/recommended.pm

Criterion	Covered	Total	%
statement	38	40	95.0
branch	12	16	75.0
condition	3	3	100.0
subroutine	8	9	88.8
pod	1	1	100.0
total	62	69	89.8

use 5.008001;
use strict;
use warnings;

package recommended;
# ABSTRACT: Load recommended modules on demand when available

use version;
use Carp ();
use Module::Runtime 0.014 (); # bugfixes for use_package_optimistically

our $VERSION = '0.003';

# $MODULES{$type}{$caller}{$mod} = [$min_version, $satisfied]
my %MODULES;

# for testing and diagnostics
sub __modules { return \%MODULES }

sub import {
    my $class  = shift;
    my $caller = caller;
    for my $arg (@_) {
        my $type = ref $arg;
        if ( !$type ) {
            $MODULES{$class}{$caller}{$arg} = [ 0, undef ];
        }
        elsif ( $type eq 'HASH' ) {
            while ( my ( $mod, $ver ) = each %$arg ) {
                Carp::croak("module '$mod': '$ver' is not a valid version string")
                  if !version::is_lax($ver);
                $MODULES{$class}{$caller}{$mod} = [ $ver, undef ];
            }
        }
        else {
            Carp::croak("arguments to 'recommended' must be scalars or a hash ref");
        }
    }
}

sub has {
    my ( $class, $mod, $ver ) = @_;
    my $caller = caller;
    my $spec   = $MODULES{$class}{$caller}{$mod};

    return 0 unless $spec; # explicit to ensure a value even in list context

    if ( defined $ver ) {
        Carp::croak("module '$mod': '$ver' is not a valid version string")
          if !version::is_lax($ver);
    }
    else {
        # shortcut if default already checked
        return $spec->[1] if defined $spec->[1];
        $ver = $spec->[0];
    }

    # don't call with a version; we want this to die only on compile failure
    Module::Runtime::use_package_optimistically($mod);

    my $ok = $INC{ Module::Runtime::module_notional_filename($mod) }
      && $mod->VERSION >= version->new($ver);

    return $spec->[1] = $ok ? 1 : 0;
}

1;


# vim: ts=4 sts=4 sw=4 et:

__END__