use Test::More; use Business::Payment::CreditCard; my $cc = Business::Payment::CreditCard->new( number => 4111111111111111, expiration => '03/20', amount => 10, ); isa_ok($cc, 'Business::Payment::CreditCard'); cmp_ok($cc->expiration_formatted('%m%y'), '==', '0320', 'expiration formatting'); done_testing;