Bare minimum react app polyfill in 9.6 KB

<script crossorigin src="https://unpkg.com/unpolyfill"></script>

1. install as a dependency

   yarn add unpolyfill

2. import at the entry of application

   import 'unpolyfill'

1. Promise (represents the eventual completion or failure of an asynchronous operation, and its resulting value)
2. window.fetch (provides an interface for fetching resources)
3. Map (holds key-value pairs and remembers the original insertion order of the keys)
4. Set (lets you store unique values of any type, whether primitive values or object references)
5. window.requestAnimationFrame (tells the browser that you wish to perform an animation and requests that the browser calls a specified function to update an animation before the next repaint)

• promise-polyfill for Promise
• unfetch for window.fetch
• core-js for Map and Set
• raf for window.requestAnimationFrame