flatMap is not a function on iOS 10

React Native version:

0.59.10

Steps To Reproduce

1. Run your app on iOS 10
2. Use Array.prototype.flatMap, e.g. [].flatMap(item => item)

Describe what you expected to happen: Should work like on other OS and platforms

Probably other new ES features don’t work too

Snack, code example, screenshot, or link to a repository:

[jd20]

To support iOS 11 and below, you can add array-flat-polyfill to your project, then add to your App.js:

import 'array-flat-polyfill'

It will only add the polyfill, if it doesn’t already exist.

[fontesrp]

This is happening in RN version 0.60.4 too

Edit Now I’m seeing the issue on iOS 11 also, with "react-native": "0.61.4"