Why does shouldPolyfill for intl-displaynames return und and not en?

[sean256]

I'm trying to get dynamic imports working, but when the locale is en or en-us the returned value from shouldPolyfill is und. This causes all output from Intl.DisplayNames to not work as expected.

Here is a runkit showing the output: https://runkit.com/embed/59hzxn8qcry8

import {shouldPolyfill} from '@formatjs/intl-displaynames/should-polyfill';
console.log(shouldPolyfill('en')); // logs out `und`

[longlho]

und is actually the same as en but I do see why it's not ideal. I've created a bug for it

[longlho]

latest version should have the fix