What are the approaches to include polyfills in your `create-react-app`?

Q: What are the approaches to include polyfills in your `create-react-app`?

There are approaches to include polyfills in create react app, 1. Manual import from core js : Create a file called (something like) polyfills.js and import it into root index.js file. Run npm install core js or yarn add core js and import your specific required features. 2. Using Polyfill service: Use the polyfill.io CDN to retrieve custom, browser specific polyfills by adding this line to index.html : In the above script we had to explicitly request the Array.prototype.includes feature as it is not included in the default feature set.

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Accepted Answer

There are approaches to include polyfills in create-react-app,

Manual import from core-js:

Create a file called (something like) polyfills.js and import it into root index.js file. Run npm install core-js or yarn add core-js and import your specific required features.

import "core-js/fn/array/find";
import "core-js/fn/array/includes";
import "core-js/fn/number/is-nan";

Using Polyfill service:

Use the polyfill.io CDN to retrieve custom, browser-specific polyfills by adding this line to index.html:

<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=default,Array.prototype.includes"></script>

In the above script we had to explicitly request the Array.prototype.includes feature as it is not included in the default feature set.