Event/Custom Event polyfill?

[ajbowler]

new Event() and new CustomEvent() don't work in older versions of IE.

The above link provides a solution and there's also custom-event-polyfill.

Are there any plans to add this to core-js/babel-polyfill?

[loganfsmyth]

Generally Babel and core-js focus on polyfilling language-standard functionality. Polyfilling features from other specifications isn't something they look to handle for you.

[zloirock]

At this moment, only ECMAScript and closely related ECMAScript features in the scope of core-js. In the future, this position can be changed, but not soon.

[ajbowler]

That makes sense, thanks for your consideration at least!

[ItamarGronich]

@zloirock Hey, since now core-js tries to follow WHATWG standards group, i think it's a good idea to re-open this and implement The Event spec: https://dom.spec.whatwg.org/#interface-event
And the CustomEvent spec: https://dom.spec.whatwg.org/#customevent

What do you think?

[zloirock]

@ItamarGronich even in 2017 when this issue was created core-js had this group. However, this group contains cross-platform features that are pretty close to ECMAScript. I agree that it makes sense to extend it, see, for example, #1020

But at this moment there are many significantly closer to ECMAScript WHATWG features that it could be good to add to core-js sooner. URLPattren, new Observable, etc...

Anyway, ok, let's reopen it.