index.js

import React from 'react';
import {BrowserRouter} from 'react-router-dom';
import {Provider} from 'react-redux';
import {createStore,applyMiddleware,compose,combineReducers} from 'redux';
import thunk from 'redux-thunk';
import burgerBuilderReducer from './store/reducers/burgerBuilder';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import orderReducer from './store/reducers/order';
import authReducer from './store/reducers/auth';
import registerServiceWorker from './registerServiceWorker';
const composeEnhancers = process.env.NODE_ENV==='development'?window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ :null|| compose;//redux tools are seen only if we are in development mode if we are not the it doesnt

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();