IE10 - IE11 getting Unable to get property 'toString' of undefined or null reference when importing 'core-js/features/string'

[ovidijusr]

After I updated the core-js version from core-js 3.0.1 to 3.1 (also in newer versions) I've found the issue for IE 10 and 11 by getting error message:
Unable to get property 'toString' of undefined or null reference

According to IE it happens here:

var symbolToString = typeof Symbol !== 'undefined' ? Symbol.prototype.toString : function () {
  return '';
};

It happens when I put string feauture before 'string' object from yup library, like this:

import 'core-js/features/string';
import { string as yupString } from 'yup';

But when I try to change the places of imports, everything works fine.

import 'core-js/features/string';
import { string as yupString } from 'yup';

My guess is that because string object from yup somehow overlaps with core-js string feauture. But the interesting thing for me is that the previous version worked fine, and also the newer (3.1+) works with edge, chrome.

I know this is nothing super important, but it looks like an interesting case

Thanks!

[zloirock]

I think that this entry point contains Symbol.matchAll polyfill, but not the full Symbol polyfill, so global Symbol in this case hasn't prototype property. You could load core-js/features/symbol before yup for fixing this issue. If it's this case, I'm not sure that it's already can be fixed on core-js side since it will break core-js entry points architecture.

[zloirock]

I'll remove exposing Symbol.matchAll from esnext.string.match-all without es.symbol.match-all. Let's hope that it will not break anything -)