Handle errors from the oauth/token endpoint

[mdlavin]

Before this change, failures from the OAuth API would result in Invalid JSON received from the Stripe API errors.

The cause was not a parse error, but an error thrown at https://github.com/stripe/stripe-node/compare/master...mdlavin:handle-oauth-errors?expand=1#diff-404ddfdf655bbca4b088b8c7242d0a3aL155 when the headers value was assigned to a string value.

The response body coming back from the oauth/token endpoint is:

{
  "error":"invalid_grant",
  "error_description":"This authorization code has already been used. All tokens issued with this code have been revoked."
}

As described in https://stripe.com/docs/connect/oauth-reference#post-token-errors

I also added a nicely typed Error for invalid_token responses, and the other OAuth failures will be reported as Generic errors instead of Invalid JSON errors

[ob-stripe]

Thanks for the contribution @mdlavin!

r? @rattrayalex-stripe

[rattrayalex-stripe]

Heya Matt! Thanks for the contribution!

Does the test fail without the added application code in lib/StripeResource.js? (Pretty sure it would).

Assuming so, this LGTM! (Will await an affirmative response, or verify myself when I have time, before merging).

[mdlavin]

Yes, the test fails without the changes in lib/StripeResource.js. I reverted to master locally and here is the failure:

  18 passing (110ms)
  1 failing

  1) StripeResource
       Retry Network Requests
         _request
           should handle OAuth errors gracefully:

      Uncaught AssertionError: expected 'StripeAPIError' to equal 'StripeInvalidGrantError'
      + expected - actual

      -StripeAPIError
      +StripeInvalidGrantError
      
      at /Users/mattlavin/Projects/stripe-node/test/StripeResource.spec.js:244:31
      at Timeout._onTimeout (lib/utils.js:39:295)

The StripeAPIError has the message Invalid JSON received from the Stripe API

[rattrayalex-stripe]

Awesome, thanks so much Matt!

[mdlavin]

@rattrayalex-stripe thanks for merging. Are new releases regularly scheduled?

[rattrayalex-stripe]

Released!

We generally try to release ~immediately after merging master; apologies for the delay.