brainlet-react/bfrontend/src/Components/App.js

import Login from './Auth/Login';
import Root from './Root';
import Authenticator from './../Authenticator';

import { useEffect } from 'react';
import { useDispatch, connect } from 'react-redux'
import { BrowserRouter, Switch, Route } from 'react-router-dom';

function App({ user }) {
    const dispatch = useDispatch();

    useEffect(() => {
        Authenticator.getLoggedInUserFromCookie()
            .then((res) => {
                dispatch({ type: 'authenticator/updatelocaluserobject', user: res })
            });
    }, [dispatch]);

    return (
        <BrowserRouter>
            <Switch>
                <Route path="/login">
                   <Login />
                </Route>
                <Route path="/">
                    <Root user={user} />
                </Route>
            </Switch>
        </BrowserRouter>
    );
}

const stateToProps = (state) => {
    return {
        user: state?.user || undefined
    };
};

export default connect(stateToProps)(App);