Exception on http status code 204

[stakach]

We're seeing an error on a 204 response from Microsoft. As you can see, MS Graph API returns an empty object as a response body on a 204 (image below)

Not sure what the HTTP standard says about 204 responses, however it seems a little heavy handed to raise an error in this case.
The application using the HTTP client can happily ignore the body if any was sent.

related to #2512

[straight-shoota]

What's the Crystal error?

[stakach]

ArgumentError here
https://github.com/crystal-lang/crystal/blob/master/src/http/client/response.cr#L19-L21

[stakach]

Seems the behaviour is quite diverse: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/204#compatibility_notes

Apple Safari rejects any such data. Google Chrome and Microsoft Edge discard up to four invalid bytes preceding a valid response. Firefox tolerates in excess of a kilobyte of invalid data preceding a valid response.

and quite annoying MS is making basic mistakes with their APIs

[straight-shoota]

Does the response in your case include a Content-Length header with nonzero value?
I think in that case it's very clear that the response can be just accepted, even though it's unexpected.

Without a Content-Length header it might be a bit more complicated, but probably not a big deal either.

[stakach]

All the browsers take the approach of ignoring the body data and making it unavailable to the user.

Given it's a success response it might make sense to follow Apples lead and just close the connection if any body data is provided - as the crystal client doesn't pipeline requests, there is no need to search for the next response.

If the crystal client treats responses, where no body is expected, with a body as valid, closes the connection and returns the headers, I think that would be improved behaviour.

[straight-shoota]

Closing the connection definitely sounds like the easiest basic solution here. We can always improve it later with fancier stuff, if necessary.