Dear future ReactJS using self, thanks to IE11, you will need to know about babel-pollyfil

Hello future self. This is a quick note on how to use the babel-polyfill.
Perhaps it is so far enough into the future that all browsers now support all of ES6 or better natively. Just in case you're still needing to support the few stubborn Internet Explorer 11 (IE11) users then you'll find this helpful.

It is November 2016 and we now use polyfills to make browsers support futures that they otherwise would not.  Here's how to use the babel-polyfill to help to make your project IE11 compatible.

In my case the specific issue was that my production code was shipping with calls to Object.assign(). Unfortunately IE11 has no idea what .assign() is. In the meantime Chrome just worked, this is how I used the polyfill approach with babel-polyfill to trick IE11 into doing Object.assign().

1. Install it with npm

This command is run in the directly that contains the package.json file:

npm i babel-polyfill --save-dev

2. Edit your webpack.config.js file to make use of it

The snippet below shows how the babel-polyfill is added to the entry array.

module.exports = {
  ...,
  entry: [
    'webpack-hot-middleware/client',
    'babel-polyfill',
    './app/client.js'
  ],

3. Import it into your project

Here's what importing babel-polyfill looks like in my project file which is located at app/client.js:

import 'react-toolbox/lib/commons.scss';
import React from 'react';
import ReactDOM from 'react-dom';
import 'babel-polyfill';
import App from './App.js';

There you go future self, if you found this helpful, you're welcome. I still need to check if this fixes IE10 compatibility issues.