socket.io client 's namespace invalid - socket.io

Question

I am running on the latest version of socket.io, the server code and client code below works well.
// server
const { Server } = require("socket.io"),
http = require('http');
const httpserver = http.createServer();
io.on("connection", async (socket) => {
socket.on("error", (err) => {
console.log(err.message);
});
socket.on('disconnect', function () {
console.log('socket disconnect');
})
});
const io = new Server(httpserver, {
cors: { origin: "*", methods: ["GET", "POST"],}
});
httpserver.listen(3001, () => {
console.log('listening on *:3001');
});
// client
import { io, Socket } from "socket.io-client";
const socket = io('ws://127.0.0.1:3001', {
transports: ["websocket"]
});
socket.on("connect_error", (err) => {
console.log(`connect_error due to ${err.message}`);
});
then I tried to work with namespace in socket.io
// server
io.of("device").on("connection", async (socket) => {
socket.on("error", (err) => {
console.log(err.message);
});
socket.on('disconnect', function () {
console.log('socket disconnect');
})
});
// client
const socket = io('ws://127.0.0.1:3001/device', {
transports: ["websocket"]
});
running the code gives me an error saying
'connect_error due to Invalid namespace''
I can't figure out what goes wrong

Answer 1

Using ws://127.0.0.1:3001/device means you are trying to reach the namespace named '/advice', which does not exist on the server.
I think you are looking for the path option instead:
const socket = io("ws://127.0.0.1:3001", {
path: "/device",
transports: ["websocket"]
});
References:
https://socket.io/docs/v4/client-initialization/
https://socket.io/docs/v4/client-options/#path
https://socket.io/docs/v4/namespaces/