Thanks for these additions !

I'm not a reviewer, but just a suggestion :

• The Stripe::Coupon.retrieve method can be added to the Stripe::Coupon class using the add_retrieve_method. Example from the code base :

@[EventPayload]
class Stripe::TaxRate
  include JSON::Serializable
  include StripeMethods

  add_retrieve_method

  getter id : String
  getter inclusive : Bool
  getter object : String?
  getter customer : String?
  getter active : Bool

  @[JSON::Field(converter: Time::EpochConverter)]
  getter created : Time
  getter description : String?
  getter jurisdiction : String?
  getter metadata : Hash(String, String)?
  getter percentage : Float32?
end

Like @rmarronnier (thanks!) - You can look through our help methods to use those to reduce repetitions and maybe remove some files. When that is done, this looks very good!

Thanks, @xaviablaza, and @rjmssevilla for the help! I appreciate it.

@confact Ready for review, could you take a look?

@xaviablaza, the test seems to fail on the SignatureVerificationError - can you check that? Otherwise, I can try to fix it as you worked so hard to fix this :)

@confact All right, I've namespaced the SignatureVerificationError under Stripe in the webhook specs and also ran the specs on my local machine. Should be good to go now, fingers crossed. 🤞 😄

@xaviablaza, the tests passed! Great job! I will merge now.