Minimal Node+Express+WS App

express_websocket_server.js

//minimal node server that opens HTTP and WebSocket ports
import path from 'path';
import express from 'express'; //for http request
import ExpressWs from 'express-ws' //for websockets

import { fileURLToPath } from 'url';
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

//create express and express websocket router
var app = ExpressWs(express()).app;

//???
app.use(function (req, res, next) {  return next(); });

//app.use(logger('dev')); //to log any HTTP request
app.use(express.static(path.join(__dirname, 'public'))); //to serve static files
app.get('/', function(req, res, next){  res.end(); }); //??

//on websocket connection, redirect to server
app.ws('/', function(ws, req) {
    console.log("User connected");
    ws.on('message', function(msg) {
        console.log("msg: ", msg)
    });
    ws.on('close', function(msg) {
        console.log("User left");
    });
});

//error handling
app.use((err, req, res, next) => {
  console.log("Error in execution");
  console.error(err.stack)
  res.status(500).send('Error in backend. Something broke!')
})

//to capture control C
process.on('SIGINT', function() {
  console.log("Caught interrupt signal");
  process.exit();
});

//start listening
var port = 3000;
console.log("Listening in port " + port)
app.listen(port);