4.4.10 release makes ws connection even when raising ConnectionRefusedError

Since this is actually an separate issue, even though on the same topic, I’m creating a new issue for it.

Open browser inspector tool, go to network->ws, and you will see a websocket connection even when you raise the ConnectionRefusedError. It stays half-connected as you can see ping events, but aren’t able to send any messages. On trying to connect using the js client socket again after I login through http (flask-session server side setup), the client socket cannot be used to connect as it is still connected.

python

@socketio.on('connect')
def connect():
    # if not current_user.is_authenticated:
    raise ConnectionRefusedError()

js

import io from 'socket.io-client';
socket = io()

// this used to be hit when on python-socketio 4.3.1
socket.on('connect_error', function(error){
  console.log(error)
}
// this is now hit on 4.4.1
socket.on('error', function(error){
  console.log(error)
}

// on connect, disconnect ...

[miguelgrinberg]

This is actually the core of the problem I’m trying to solve. I haven’t looked specifically at the JS client yet, but yes, the idea is that the connection error should be invoked when the server declines a connection.

[acnebs]

Right, that makes sense, thanks for the explanation.

The issue I’m having is that I don’t know where I’m supposed to handle the raised exception on the client-side (when using the JS client). Obviously the JS library isn’t your purview, but one generally hopes that the various SocketIO libs should seamlessly interoperate with each other. But when I read through the python-socketio client docs, I couldn’t seem to find much guidance there either for this situation.

In the python-socketio client, is it the connect_error() handler that handles both the return False method and the raise ConnectionRefusedError("info") method for short-circuiting a connection? And am I right in thinking that the args in connect_error() are the args passed into the ConnectionRefusedError?

Because when using the JS client lib, my error handler is triggered when I return False server-side in both 4.3.x and 4.5.x. Meanwhile, neither my client-side error nor my connect_error handlers are being triggered when I call raise ConnectionRefusedError() on the server side (in both mentioned versions). The JS client has “support” for connect_errors, it just seems like raising an exception in the python-socketio server isn’t doing what the JS client expects.