Handshake requires 101 response; conflicts with WebSockets over H2/H3 (Extended CONNECT) #70
Description
What is the issue with the WebSockets Standard?
The opening-handshake algorithm step 11.1 says: “If response is a network error or its status is not 101, fail the WebSocket connection.”
This is correct for HTTP/1.1 Upgrade, but rejects successful WebSocket handshakes over HTTP/2 and HTTP/3, which use Extended CONNECT and signal success with a 2xx response.
At minimum that step needs to accept 2xx, I think.
It might also be worth a note that the H/1.1+101 path this spec models (Upgrade: websocket, Connection: Upgrade, Sec-WebSocket-Key etc) doesn't work with HTTP/2 and HTTP/3 which instead require bootstrapping WS over H2/H3 using Extended CONNECT per RFC 8441 / 9220 respectively (helps readers discover the RFCs).
Updating the steps themselves seems hard given the type of connection is not known ahead of fetch (unless perhaps the request can be passed to obtain a WebSocket connection for modding?)