generator-prospa/generators/app/templates/front-end/react/src/index.js

Create fully working Single Page Applications using various technology combinations

import React                    from 'react'
import ReactDOM                 from 'react-dom'

import { BrowserRouter, Route } from 'react-router-dom'

import App                      from './App'

import * as serviceWorker       from './serviceWorker'

import './index.css'

ReactDOM.render(
    <BrowserRouter>
        <Route component={App}/>
    </BrowserRouter>,
    document.getElementById('root')
)

// If you want your app to work offline and load faster, you can change
// unregister() to register() below. Note this comes with some pitfalls.
// Learn more about service workers: https://bit.ly/CRA-PWA
serviceWorker.unregister()