Background & Context

I was upgrading DOMPurify from v2.x to v3.x and when I checked the release notes to check the breaking changes, I realized I shouldn't worry because the only theoretical change was the IE support overhead.

Happy with the outcome, I decided to check how much code was removed, and then for my surprise, Bundlephobia said that this package is 0.3kb bigger now (after minifying / gzipping) than it was before 🤔.

Then I decided to check the code itself, and I realized that by changing for…in to for…of, a lot of code was added by Babel:

2.4.5...3.0.1#diff-48108d9bf161db3408a0fc8e8f7ab693247d39db9998ff4cd0d9c3de233dd09aR54-R310

I think this happens because DOMPurify still supports very old versions of some browsers, eg Chrome 22 (for…of was implemented only in Chrome 38, for example).

Is there any reason why these very old browsers are still supported? Especially since we're talking about evergreen browsers.