WebSocket connection failed: Error during WebSocket handshake: Unexpected response code: 400

Question

I am trying to integrate Socket.io with Angular and I\'m having difficulties making a connection from the client-side to the server. I\'ve looked through other related quest

Answer 1

Judging from the messages you send via Socket.IO socket.emit('greet', { hello: 'Hey, Mr.Client!' });, it seems that you are using the hackathon-starter boilerplate. If so, the issue might be that express-status-monitor module is creating its own socket.io instance, as per: https://github.com/RafalWilinski/express-status-monitor#using-module-with-socketio-in-project

You can either:

1. Remove that module

2. Pass in your socket.io instance and port as websocket when you create the expressStatusMonitor instance like below:

   const server = require('http').Server(app);
   const io = require('socket.io')(server);
   ...
   app.use(expressStatusMonitor({ websocket: io, port: app.get('port') }));