Errors related to btoa/atob in IE11 after upgrading to latest core-js version

[tardiva]

After upgrading core-js in our app to latest 3.27.1 version we found that the app stopped working in IE11. Seems that the last stable version for us is 3.21.1 and critical changes were made here.

I prepared minimal example for reproducing the issue.

Run npm start in main branch and note that alert is shown in Chrome but it is not shown in IE11

Then change the branch to use core-js version 3.21.1. Note that alert works as expected in both browsers.

[zloirock]

It seems a webpack dev server bug that incorrectly eval code. Your code compiled usually, without eval, works fine.

[zloirock]

Similar to #62 - it seems webpack didn't fix this bug already 8 years.

[zloirock]

I added a workaround.