Main.js

import React, { Component } from 'react';
import {
  StyleSheet,
  Text,
  View,
  Image,
} from 'react-native';
import { Root } from './router';

class AppRoot extends Component {
  render(){
      if ( this.props.auth ) return <Root />
      return(
        <RootLogin />
      )
    }
  }
}

export default () => <AppRoot />;

  render() {
    const { isLoading, token } = this.state;

    if (isLoading) return null;

    console.log('Token  =====>  ', token);
    if (!token) return <Main updateToken={this.updateToken} />;
    return <Main updateToken={this.updateToken} auth />;
  }