Add HTMLElement#attachInternals()

[naokikimura]

Fixes microsoft/TypeScript#33218

microsoft/TypeScript#36347 was rejected, so I made this PR.

Rather, please tell me why you removed it.

[msftclas]

All CLA requirements met.

[naokikimura]

@sandersn I would appreciate it if you could review this

[saschanaz]

Rather, please tell me why you removed it.

Those types have only one implementation which is from Chromium, that's why it's removed from here.

[naokikimura]

@saschanaz

Thank you for commenting.

Implemented in Chromium means that its functionality is available in many web browser products, such as Google Chrome, Microsoft Edge and Opera.

Also, it is already implemented in Firefox Nightly. https://hg.mozilla.org/mozilla-central/rev/e6b60876e668

Does the implementation of that method need to be completed in stable version?

[saschanaz]

Does the implementation of that method need to be completed in stable version?

Yes, as Nightly can always drop it without shipping it to stable.

[adriengibrat]

What about moving definitions in a separated file, so it's up to the user to use it or not (like some ES features) ?

[saschanaz]

Currently Definitely Typed is recommended for that purpose.

[orta]

I tested support for Firefox and Safari via this glitch app and they're still not available un-flagged: https://web.dev/more-capable-form-controls/#a-working-example

We're still happy to wait until that changes, otherwise as @saschanaz says DT is your best option to get it shipped today

[saschanaz]

#1141 and #1149 partially restored ElementInternals types thanks to the new Firefox implementation. Others will be restored when further implementation happens.

@github-actions close

[github-actions]

Closing because @saschanaz is one of the code-owners of this repository.