Choose close code and reason on response

[ErwanDL]

Currently, when the closing handshake is initiated by the other side of the WebSocket connection, we can't customize the CloseFrame of the response: it is automatically set to CloseFrame { code: CloseCode::Normal, reason: "".into() }, cf https://github.com/snapview/tungstenite-rs/blob/master/src/protocol/mod.rs#L562-L565.

This is problematic for my use case, where I would like to customize the CloseCode in the response (typically, I want the response to match the CloseCode of the closing request, so if the client closes with CloseCode::Library(4000) I want the server to respond with the same code).

Is there any way or workaround to make this work ?

[daniel-abramov]

According to the RFC:

If an endpoint receives a Close frame and did not previously send a
Close frame, the endpoint MUST send a Close frame in response. (When
sending a Close frame in response, the endpoint typically echos the
status code it received.)

So perhaps we could echo the frame that we received when sending the response. I think that it would be indeed a better behavior and also should solve the problem you have.

[ErwanDL]

That would be great, thank you! Do you know in what release this change will come out?

[daniel-abramov]

Ok, so the changes have just been merged, so I think with the next release we'll include this change!

If you need it right now, you could for sure rely on the version from master for now.