How to use socket.io in React Native

app.js

// You need to set `window.navigator` to something in order to use the socket.io
// client. You have to do it like this in order to use the debugger because the
// debugger in React Native runs in a webworker and only has a getter method for
// `window.navigator`.
window.navigator.userAgent = 'ReactNative';

// Need to require instead of import so we can set the user agent first
// This must be below your `window.navigator` hack above
const io = require('socket.io-client/socket.io');
const socket = io('http://chat.feathersjs.com', {
  transports: ['websocket'] // you need to explicitly tell it to use websockets
});

socket.on('connect', () => {
  console.log('connected!');
});

i am seeing warning socket.on is unresolved function or method. why? can anyone help me? and also i am getting this warning

Setting a timer for a long period of time, i.e. multiple minutes, is a performance and correctness issue on Android as it keeps the timer module awake, and timers can only be called when the app is in the foreground.