How to test such class behavior in Rspec - ruby-on-rails

Question

I have a class which is responsible for dealing with some response from payments gateway.
Let's say:
class PaymentReceiver
def initialize(gateway_response)
#gateway_response = gateway_response
end
def handle_response
if #gateway_response['NC_STATUS'] != '0'
if order
order.fail_payment
else
raise 'LackOfProperOrder'
# Log lack of proper order
end
end
end
private
def order
#order ||= Order.where(id: #gateway_response['orderID']).unpaid.first
end
end
In payload from payment I've NC_STATUS
which is responsible for information if payment succeed and orderID which refers to Order ActiveRecord class byid`.
I would like to test behavior(in rspec):
If PaymentReceiver receives response where NC_STATUS != 0 sends fail_payment to specific Order object referred by orderID.
How you would approach to testing this ? I assume that also design could be bad ...

Answer 1

You have to make refactorization to remove SRP and DIR principles violations.
Something below I'd say:
class PaymentReceiver
def initialize(response)
#response = response
end
def handle_response
if #response.success?
#response.order.pay
else
#response.order.fail_payment
end
end
end
# it wraps output paramteres only !
class PaymentResponse
def initialize(response)
#response = response
end
def order
# maybe we can check if order exists
#order ||= Order.find(#response['orderID'].to_i)
end
def success?
#response['NCSTATUS'] == '0'
end
end
p = PaymentReceiver.new(PaymentResponse({'NCSTATUS' => '0' }))
p.handle_response
Then testing everything is easy.