reactjs - React-router - check for empty state and redirect?

How can I check for empty state and redirect to the first route, if needed?

I have my routes.js

export default (
    
        
        ;
        
        
        
        

        
    
);

and my index.js

const store = configureStore();
console.log({ store });
render(

    
        
    ,
    document.getElementById('root')
);

How would I do that using react-router

app.js

import React, { PropTypes } from 'react';
import Header from './common/Header';
import ModalRoot from './modals/Modal';
import Footer from './common/Footer';
class App extends React.Component {
    render() {
        return (
            

                

                

                {this.props.children}
                

            
        );
    }
}

App.propTypes = {
    children: PropTypes.object.isRequired,

};

export default App;