No response from Socket.io server when client is making a connection - node.js

Question

I have been fighting with setting this up for longer than I would like to admit.
At first, I was having CORS issues, after following what the socket.io documentation / other stack overflow threads I was getting hit with, GET / POST 400 errors.
Finally after that, I noticed a few threads mention to pass in {transports: ['websocket']} on the server and in the client.
Once I did that, I stopped getting error messages, however, I am still not able to make a connection from my client to my socket.io server. I am hoping I can get some guidance.
I am running Socket.io 3.0 and express 4+
Here is what my server / client looks like at the moment..
SERVER (As an express router)
const express = require('express');
const socketIO = require("socket.io");
const http = require('http');
let app = express();
let router = express.Router();
let server = http.createServer(app);
// The event will be called when a client is connected.
let io = socketIO(server, {transports: ['websocket']})
io.on("connection", socket => {
console.log("connection")
socket.emit("hello", { data: "more data" })
socket.on("disconnect", () => {
console.log("user left")
})
})
server.listen(8081, () => console.log('Socket.io listening on *:8081'));
module.exports = router;
Client (React)
// Socket.IO
import io from 'socket.io-client';
const socket_io = io('localhost:8081', {transports: ['websocket']})
// Socket.io UseEffect
useEffect( () => {
const initSocket = () => {
console.log(socket_io)
socket_io.on("hello", data => {
setSocket(data);
console.log(data);
});
// CLEAN UP THE EFFECT
return () => socket_io.disconnect();
}
initSocket()
},[])
Here is what my Console currently looks like when I log out the socket connection:

Answer 1

So, as embarrassing as this is, the breaking change was that the socket.io-client module in the React client application wasn't 3.0 like the one on the server. Therefore they weren't able to handshake.
My advice, is if you have the CORS rule added or the transport: websocket added, make sure you look at your package.json file in your server / client apps to make sure that the socket.io package version matches.