index.js

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import { BrowserRouter } from 'react-router-dom';
import { createStore, applyMiddleware, compose } from 'redux';

import './index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';
import rootReducer from './reducers/index';

const composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;

const store = createStore(rootReducer, composeEnhancers( 
  applyMiddleware()
));

ReactDOM.render(
  <Provider store={store}> 
    <BrowserRouter>
      <App />
    </BrowserRouter>
  </Provider>, document.getElementById('root'));
registerServiceWorker();