Untainting data in Moose::Util::TypeConstraints

gistfile1.txt

[user@host dev]$ ./test.pl 20121112

20121112 is tainted!

$VAR1 = bless( {
                 'date' => '20121112',
               }, 'Index' );

date is NOT tainted!

Index.pm

package Index;

use Moose;
use namespace::autoclean;
use Index::Types;
use POSIX qw(strftime);

has 'date'    => (
     is       => 'rw',
     isa      => 'Index::Types::Date',
     default  => sub {strftime '%Y%m%d', gmtime;},
     coerce   => 1,
);

_PACKAGE__->meta->make_immutable();

test.pl

#!perl -T

use Modern::Perl;
use lib 'lib';
use Index;
use Data::Dumper;
use Scalar::Util qw(tainted);
use Try::Tiny;

my $date = $ARGV[0];

say "$date is tainted!" if tainted($date);

my $index;

try {
    $index = Index->new( date => $date );

    say Dumper($index);
    say "date made it through moose tainted!" if tainted($index->date);

} catch {
     $_ =~ m/__START__(.*)__END__/;

    if (defined $1) {
        say $1;
    } else {
        say "SYSTEM ERROR! $_";
    }
};

say "date is NOT tainted!" unless tainted($index->date);

Types.pm

package Index::Types;

use Moose::Util::TypeConstraints;
use Scalar::Util qw(tainted);

subtype 'Index::Types::Date'
        => as 'Str'
        => where { ( m/^[0-9]{8}$/ && !tainted($_) ) }
        => message { "__START__This date ($_) is not a valid date!__END__"};

coerce 'Index::Types::Date',
    from 'Str',
    via {
          $_ =~ s/[^0-9]//g; # Strip anything that isn't a digit.
          $_ =~ m/^([0-9]{8})$/ or die "__START__The date is not a valid!__END__";
          return $1;
        };

1;