Making a Socket io singleton class to be used in any file - node.js

Question

I need access to the io module in multiple files in my project so I can emit some messages. So for that I decided to create a singleton class to handle the io object so i can import the class anywhere and use the io object.
When I comment out all the middleware, it works. But I don't want that, I want the connection to be only made when the user is logged in.
here's my socketClass.js
const session = require('express-session');
const { Server } = require("socket.io");
const passport = require('passport');
class SocketManager{
constructor() {
this.io = null;
}
start(server) {
this.io = new Server(server);
// convert a connect middleware to a Socket.IO middleware
const wrap = middleware => (socket, next) => middleware(socket.request, {}, next);
const sessionMiddleware = session({
secret: 'MySecrectKey',
resave: true,
saveUninitialized: true
});
this.io.use(wrap(sessionMiddleware));
this.io.use(wrap(passport.initialize()));
this.io.use(wrap(passport.session()));
this.io.use((socket, next) => {
if (socket.request.user) {
next();
} else {
next(new Error('unauthorized'))
}
});
}
get() {
return this.io;
}
}
module.exports = new SocketManager();
Here's my app.js
...
const SocketManager = require('./socketClass');
const server = http.createServer(app);
SocketManager.start(server);
const io = SocketManager.get();
io.on('connect', async (socket) => {
console.log(`new connection ${socket.id}`);
socket.on('whoami', (cb) => {
cb(socket.request.user ? socket.request.user.username : '');
});
});
The io.on('connect') wont console.log anything on a new connection. What is the problem here?

Answer 1

Your problem may be because of "async (socket)". Here is how I do it as simply as possible !
I created a separate file (module):
socket.js:
let io;
module.exports = {
init: httpServer => {
io = require('socket.io')(httpServer);
return io;
},
getIO: () => {
if (!io) {
throw new Error('Socket.io not initialized!');
}
return io;
}
};
Then, in my app.js:
const app = express();
const server = app.listen(8080);
const io = require('./socket').init(server);
io.on('connection', socket => {
console.log('Client connected');
});