use strict;
use warnings;
package CB;
use HTML::FormFu;
my $form = HTML::FormFu->new;
$form->element('Text')->name('foo')->constraint('Callback')->callback( \&cb );
$form->element('Text')->name('bar')->constraint('Callback')
    ->callback("CB::cb");
sub cb {
    my $value = shift;
    ::ok(1) if grep { $value eq $_ ? 1 : 0 } qw/ 1 0 a /;
    return 1;
}
package main;
use Test::More tests => 5;
# Valid
{
    $form->process( {
            foo => 1,
            bar => [ 0, 'a', 'b' ],
        } );
    ::ok( $form->valid('foo'), 'foo valid' );
    ::ok( $form->valid('bar'), 'bar valid' );
}