Basic React App: very simple code for starting a single-file react app

reactApp.js

import React from 'react';
import { Router, Switch, Route } from 'react-router-dom';
import ReactDOM from 'react-dom';
import { createBrowserHistory } from 'history';

const history = createBrowserHistory();

const App = () => {
  return (
    <Router history={history}>
      <Switch>
        <Route exact path="/">
          </>
        </Route>

        <Route
          key="foo"
          path="/foo"
          component={</>}
        />
      </Switch>
  );
};

ReactDOM.render(<App />, document.getElementById('root'));