socket.io-client: version 2.2 does not work with react native

Nothing seems like to be working with react native 0.60

socket.io (unlike the WebSocket API) only accepts a HTTP(S) protocol URI for the client (see the docs here), but it does use the WS protocol behind the scenes.

So if you do io('http://192.168.0.107:8080/endpoint', ...) it should work!

Yep, I’m currently running socket.io-client@2.2.0 (which has pulled in engine.io-client@3.3.2) on React Native without issue.

It’s worth checking to make sure your engine.io-client is 3.3.2, as this contains the React Native fix for websockets. 😃

@benhjames thanks for the update!

I think the ws:// should work properly, but the /endpoint means you want to connect to the endpoint namespace (that’s the current implementation, as of v2.x). You may want to use:

this.socket = io('ws://192.168.0.107:8080', {
  path: '/endpoint',
  reconnection: true,
  reconnectionDelay: 500,
  jsonp: false,
  reconnectionAttempts: Infinity,
  transports: ['websocket']
});

That looks to me like the endpoint is incorrect - it should be a http or https protocol link, not a ws one. 👍

I tried with Expo SDK v34 and v35 (RN 0.59) and had to downgrade socket.io-client to 1.7.2 (yarn add socket.io-client@1.7.2) as other versions (2.1.1, 2.1.0, 2.2.0) did NOT work. I didn’t try 2.3.0, now that it works I don’t want troubles 😃

Please see the above answer!

It may be needed to connect to a non-localhost URL (i.e. your computer’s IP) within React Native: certainly in Android and possibly in iOS depending on which simulator is being used.

If that still doesn’t work, then it’s worth trying the transports: ['polling'] option to see if it really is the WebSocket transport in particular that’s not working, or if it’s a more general network connection problem.

That explains it then! Socket.io needs to be used on both the client and server to work. 👍

@benhjames @darrachequesne I have used socket.io-client@2.2.0 (which has pulled in engine.io-client@3.3.2) and also verify the changes in node_modules still, it’s not working for me.

`import io from ‘socket.io-client’;

export default class HomeScreen extends React.Component { constructor(props){ super(props); this.socket = io(‘ws://192.168.0.107:8080/endpoint’,{ reconnection: true, reconnectionDelay: 500, jsonp: false, reconnectionAttempts: Infinity, transports: [‘websocket’] }); this.socket.on(‘connect_error’, (err) => { console.log(err) });
} `

I am getting the error as below : Error: websocket error at WS.Transport.onError (transport.js:67) at WebSocket.ws.onerror (websocket.js:157) at WebSocket.dispatchEvent (event-target.js:172) at WebSocket.js:289 at RCTDeviceEventEmitter.emit (EventEmitter.js:190) at MessageQueue.__callFunction (MessageQueue.js:349) at MessageQueue.js:106 at MessageQueue.__guard (MessageQueue.js:297) at MessageQueue.callFunctionReturnFlushedQueue (MessageQueue.js:105) at debuggerWorker.js:72