Fix for issue 222

[helgridly]

Raise HTTPError without attempting to unmarshal the response if the status code isn't 2xx.

[coveralls]

Coverage remained the same at 97.449% when pulling bff6722 on helgridly:fix_222 into 3c73bd3 on Yelp:master.

[sjaensch]

Thank you for the contribution! I think this is going too far though. We have services in production that return properly formatted JSON responses for e.g. 403, 404 HTTP status codes. We should either limit this to >= 500 or maybe check if there is a response defined in the spec for the status code, and if we do then unmarshal.

[macisamuele]

I would prefer to not run the unmarshal_response method only if the operation object has no knowledge about the response format or if the content type is not application/json (#250).

The swagger specs allow you to define the response format also for not HTTP/200 cases, like in the Operation Object Example (where is defined the format of the HTTP/405 case).

I believe that checking that incoming_response.content_type is a JSON could be enough.

if self.operation is not None and incoming_response.content_type is 'application/json':

[helgridly]

The "throw an HTTPError if there's no response format defined" idea sounds like a good one. My only concern is that users (i.e. me) now have to handle non-2xx codes differently, based on whether the server returns JSON or not - and that one case looks "normal" while the other raises an exception. Does this sound like a problem to you? Should we just return the incoming response for unmarshalable non-2xx codes too, and skip the exception entirely?

edit:\ Oh, I just found this.

[helgridly]

I dug into what's happening in my case some more and discovered I've run into a discrepancy between what Swagger describes and what we actually return. I'm happy for this to be closed if it's unhelpful, since it's user error.