index.js

import React from 'react';
import './index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';

import ReactDOM from 'react-dom';
import { BrowserRouter } from 'react-router-dom';

import {Provider} from 'react-redux';
import {createStore, applyMiddleware, compose, combineReducers } from 'redux';
import burgerBuilderReducer from './store/reducers/burgerBuilder';

import thunk from 'redux-thunk';
import orderReducer from './store/reducers/order';

import authReducer from './store/reducers/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();