TypeError: Cannot read property ‘getState’ of undefined

If we look inside react-redux <Provider />

<Provider /> expects to be provided a store prop:

this.state = {
  storeState: store.getState(),
                   ^^here
  store
}

Hence the error.

You can create one, though, using a reducer, should be something similar to this:

import React from 'react'
import { render } from 'react-dom'
import { Provider } from 'react-redux'
import { createStore } from 'redux'
import reducer from './reducer'
import App from './components/App'

const store = createStore(reducer)

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

You need to add a store to your provider.

If you don't have any reducer, you can add a dummy reducer.

Assume that the dummy reducer returns an empty array.

() => []

So, your code will be changed to:

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

const store = createStore(() => [], {}, applyMiddleware());

import './index.css';

const App = () => (<div>Hi </div>);

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