F_A_8_Test_app/src/PrivateRouter.js

import React from 'react';
import { Route, Redirect } from 'react-router';
import * as routes from './constants/routes';

export default ({ component: Component, user, ...rest }) => (
    <Route
        {...rest}
        render={props => (
            user
                ? <Component {...props} />
                : <Redirect to={routes.SIGN_IN} />
        )}
    />
)