JupyterLab v4 Support

[bsdz]

Is there anything that would prevent jupyterlab v4 (4.0.5) from connecting to an existing gateway (v3.2.2)? I testing out the new version of lab but when I try to execute anything in the kernel I see an error in the gateway console:

D 2023-08-18 16:00:24.067 EnterpriseGatewayApp] activity on 02d32feb-09c2-478f-8a34-f96ee66d3d1f: status (idle)
[E 230818 16:00:24 web:1798] Uncaught exception GET /api/kernels/02d32feb-09c2-478f-8a34-f96ee66d3d1f/channels (192.168.251.219)
    HTTPServerRequest(protocol='http', host='192.168.251.219:8887', method='GET', uri='/api/kernels/02d32feb-09c2-478f-8a34-f96ee66d3d1f/channels', version='HTTP/1.1', remote_ip='192.168.251.219')
    Traceback (most recent call last):
      File "/home/blair/projects/dev-settings/pyenvs/jupyter-notebook/.venv/lib/python3.10/site-packages/tornado/websocket.py", line 635, in _run_callback
        result = callback(*args, **kwargs)
      File "/home/blair/projects/dev-settings/pyenvs/jupyter-notebook/.venv/lib/python3.10/site-packages/jupyter_server/services/kernels/handlers.py", line 521, in on_message
        msg = json.loads(ws_msg)
      File "/usr/lib/python3.10/json/__init__.py", line 346, in loads
        return _default_decoder.decode(s)
      File "/usr/lib/python3.10/json/decoder.py", line 337, in decode
        obj, end = self.raw_decode(s, idx=_w(s, 0).end())
      File "/usr/lib/python3.10/json/decoder.py", line 355, in raw_decode
        raise JSONDecodeError("Expecting value", s, err.value) from None
    json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
[D 2023-08-18 16:00:24.067 EnterpriseGatewayApp] Websocket closed 02d32feb-09c2-478f-8a34-f96ee66d3d1f:9fa06ffa-1a75f933f637432257c406e9

[kevin-bates]

You might be running into this issue: jupyter-server/jupyter_server#1310

It looks like it can be worked around via configuration. I would try the work around to see if it resolves your issue.

[bsdz]

That worked! Thank you very much :)