Update app.js

app.js

@@ -26,6 +26,7 @@ app.get('/', (req, res) => {
     let ws, currentRoom = null;
 
     function joinRoom() {
+    try {
       const roomId = document.getElementById('room').value;
       ws = new WebSocket('ws://' + location.host);
       ws.onopen = () => {
@@ -39,6 +40,9 @@ app.get('/', (req, res) => {
         log('[' + msg.roomId + '] ' + msg.message);
       };
       ws.onclose = () => log('Disconnected.');
+      } catch (err) {
+      alert("err "+err) 
+      }
     }
 
     function sendMsg() {
@@ -58,6 +62,7 @@ app.get('/', (req, res) => {
 
 wss.on('connection', ws => {
   let currentRoom = null;
+  console.log("fresh connect")
 
   ws.on('message', raw => {
     let msg;