Socket.io client is not connecting to the server - express

Question

I am trying to connect to the socket.io client using the following server-side code...
const express = require("express");
const { createServer } = require("HTTP");
const { Server } = require("socket.io");
const app = express();
const httpServer = createServer(app);
const io = new Server(httpServer);
io.on("connection", (socket) => {
console.log("New user connected");
socket.on("join_room", (room) => {
socket.join(room);
socket.on("message", (msg) => {
io.to(room).emit("update_msg", msg);
});
});
});
const PORT = process.env.PORT || 5000;
httpServer.listen(PORT, () => {
console.log(`Server has started on port number ${PORT}`);
});
My client-side code is as follows.
const socket = io("http://localhost:5000");
socket.emit("join_room", "Room1");
When I am running the above codes it does not print anything in the console. I am using socket.io and socket.io-client version 4.5.0 on the server-side and client-side respectively.

Answer 1

const express = require("express");
const { createServer } = require("http");
const { Server } = require("socket.io");
const cors = require('cors')
const app = express();
app.use(cors())
const httpServer = createServer(app);
const io = new Server(httpServer, { cors: {
origin: "http://localhost:4200",
methods: ["GET", "POST"]
}});
io.on("connection", (socket) => {
console.log("New user connected");
socket.on("join_room", (room) => {
socket.join(room);
socket.on("message", (msg) => {
io.to(room).emit("update_msg", msg);
});
});
});
const PORT = process.env.PORT || 5001;
httpServer.listen(PORT, () => {
console.log(`Server has started on port number ${PORT}`);
});
Hope above code will work.
Please confirm, Did you enable the CORS?, if you're trying to access from different origin.
For your'e reference, I have added the CORS while creating the HTTP Server
Ref: https://socket.io/docs/v3/handling-cors/