socket.io client catch error : " WebSocket connection to failed: Error in connection establishment:" object

Question

I am trying to catch connection failed error if the given host is not correct or cannot be reached.but it seems this error is logging from websocket itself and is not related to shocket io it self.

WebSocket connection to 'ws://file/socket.io/?EIO=4&transport=websocket' failed: Error in connection establishment:.net::ERR_NAME_NOT_RESOLVED

I tried this catch errors naming events:

        socket.on("connect_error", (error)=>{
            console.log(error)
        })
        socket.on("connect_failed", (error)=>{
            console.log(error)
        })
        socket.on("error", (error)=>{
            console.log(error)
        })

but none of them are working.

research:

https://github.com/socketio/socket.io-client/issues/1097

I tried this option on my socketio client instance:

const socket = require('socket.io-client')('https://somefoo.com', {
  transports: ['websocket'],
  rejectUnauthorized: false
})

Answer 1

What you can try to do, is to use the socket.io manager which is catching errors of a higher level.

https://socket.io/docs/v3/client-api/#Event-%E2%80%98error%E2%80%99

https://socket.io/docs/v3/client-api/#Manager

    const manager = new Manager('https://somefoo.com')
    const socket = manager.socket('/')

    manager.on('error', (error) => {
        // Fired upon a connection error.
        console.log('socket error')
    })

    socket.on('connect_error', (error) => {
        // Fired when an namespace middleware error occurs.
        console.log('connection error')
    })