Bug description

Websocket requests are not mapped via mappath. The function is not even called on the websocket URL.

How to reproduce

Write a small server proxy that contains a websocket request, use the mappath config argument to define a function that e.g. just prints and returns the current path. It is not called for the websocket request, the console shows

Trying to establish websocket connection to ws://...
Websocket connection established to ws://...

where ws://... is the original path, not mapped using mappath.

Expected behaviour

ws://... should be a path mapped using the custom mappath function.

Actual behaviour

ws://... is the original, unmapped path.

Your personal set up

• OS: Fedora Workstation 41

• Version(s): Jupyter Server Proxy version 4.4.0