fix for empty body on 204 status code

[pvmeerbe]

According to HTTP spec,status code 204 should not have a body The current code checks for 'response.body' to achieve this.

However Rack sends empty string as body for a 204 status code which is considered a body when using the response.body check. As a result deserializing from Json fails. using .present? solves this issue

related rack information:

• example use in test : line 207 in https://github.com/rack/rack/blob/master/test/spec_response.rb
• code : line 63 in https://github.com/rack/rack/blob/master/lib/rack/response.rb
• code introduced in commit https://github.com/rack/rack/commit/c525c2871a0de628786233077ac3603e9fe5d8e4
• rack specifications : lines 238 till 244 in https://github.com/rack/rack/blob/master/SPEC

[gamache]

Thanks for the patch! But Object#present? is a Rails method, not pure Ruby. I'd also like a test case if this is to make it into master.

[pvmeerbe]

I reworked the .present? function & added related tests.

I also provided a fix specifically for Grape with status 405 response (see last commit)

[gamache]

Thanks for the patch! Merging. :+1: