index.js

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

import './index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';
import burgerBuilderReducer from './store/reducer/burgerBuilder';
import orderReducer from './store/reducer/order';
import authReducer from './store/reducer/auth';

const composeEnhancers =
	process.env.NODE_ENV === 'development'
		? window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__
		: null || compose;

const rootReducer = combineReducers({
	burgerBuilder: burgerBuilderReducer,
	order: orderReducer,
	auth: authReducer,
});

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

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