• Source: github.com/alovak/bank_card

• Bugs: github.com/alovak/bank_card/issues

This gem contains validation of card number with Luhn method, card brand detection (Visa, MasterCard, etc.)

class CreditCard < ActiveRecord::Base
  include BankCard::Validations

  validates :number, :luhn => true
  validates_expiration_of :date
end

You can get more info from specs

released under the MIT license.