A pure WebSocket echo server (like echo.websocket.org)

chatroom.js

// chatroom.js
var WSServer = require('ws').Server
  , wss      = new WSServer()
  
// handle only pure clean websockets
wss.on('connection', function(ws) {
  // broadcast new connection count
  wss.sockets.forEach(function(s) {
    s.send(wss.sockets.length)
  })
  // broadcast incoming message
  ws.on('message', function(message) {
    wss.sockets.forEach(function(s) {
      s.send(message)
    })
  })
})