Additional headers for WS accept message.

[matiuszka]

Hello,

Here is a proposal for improvement about supporting additional headers for the WebSocket accept messages.
As per disscuision in gitter:

Hello,
I recently faced the problem with sending custom headers in WS accept messages. According to ASGI, it should be possible:
https://asgi.readthedocs.io/en/latest/specs/www.html#accept-send-event
I've created an issue and MR for Hypercorn to support that:
pgjones/hypercorn!66
although I am forced to use bare send for this.
Do you think that it can be supported by Starlette's API? If yes, let me know I can create PR.
Here is the proposal: matiuszka/starlette@a080bf5

[Kludex]

It would be cool to have this supported by unicorn as well (although is not a prerequisite).

[matiuszka]

@Kludex I will handle it soon.

[matiuszka]

Here is PR for uvicorn: encode/uvicorn#1293

[Kludex]

Just a single comment. Thanks @matiuszka ! 😄

[Kludex]

Besides that, everything is cool!

Thanks @matiuszka ! 😄

[Kludex]

Thanks @matiuszka ! 😄

[Kludex]

This should probably be message.get("headers", []) with #1422

[aminalaee]

I think this part is ok. When passing None you'll need to check assert websocket.extra_headers is None but with that change:

def test_additional_headers(test_client_factory):
     def app(scope):
         async def asgi(receive, send):
             websocket = WebSocket(scope, receive=receive, send=send)
             await websocket.accept(headers=None)
             await websocket.close()

         return asgi

     client = test_client_factory(app)
     with client.websocket_connect("/") as websocket:
         assert websocket.extra_headers == []

Am I missing something?

[Kludex]

You're not. I don't have strong feelings on this. 👍