const express = require("express"); const app = express(); const PORT = 4000; app.use(express.urlencoded({ extended: true })); app.use(express.json()); const http = require("http").Server(app); const cors = require("cors"); const socketIO = require('socket.io')(http, { cors: { origin: "" } }); //👇🏻 Add this before the app.get() block socketIO.on('connection', (socket) => { console.log(`⚡: ${socket.id} user just connected!`); socket.on("singIn", (test) => { console.log(test); }); socket.on('disconnect', () => { socket.disconnect() console.log('🔥: A user disconnected'); }); }); app.get("/api", (req, res) => { res.json({ message: "Hello world", }); }); app.listen(PORT, () => { console.log(`Server listening on ${PORT}`); });