gistfile1.rb

## Test
require 'active_merchant'

class Foo
  include ActiveMerchant::Billing::CreditCardMethods
end

describe Foo do
  it "should respond to methods in CreditCardMethods" do
    @foo = Foo.new
    @foo.should respond_to(:valid_month?)
    @foo.should respond_to(:valid_number?)
  end
end

## Failure

Failures:

  1) Foo should respond to methods in CreditCardMethods
     Failure/Error: @foo.should respond_to(:valid_number?)
       expected #<Foo:0x00000102afe008> to respond to :valid_number?
     # ./spec/models/subscription_spec.rb:11:in `block (2 levels) in <top (required)>'