extension type auto import

[cedvdb]

Related #38894

extension type UserId(String _value) implements String {}

I'd expect the above to be discoverable and not have to manually type the import each time.

[lrhn]

It should be as discoverable as a class. If it isn't, that is probably a mistake.

[Tienisto]

The extension is visible while writing (autocomplete) but there is no "Quick Fix" after the extension type has been already written.

[denniskaselow]

The quick fix is available on the constructor:

But not on the type:

[cedvdb]

This was closed but the PR above was not merged ?

[FMorschel]

@cedvdb
Yes, it was a little weird the first time I saw this. The issue was closed on Gerrit. If you take a look at the PR there is a bot telling you about a new link:

https://dart-review.googlesource.com/c/sdk/+/386701

This is where the code got merged. They usually don't use PRs I was starting to help when I opened it. They use CLs directly at Gerrit. Since the code was already committed in Gerrit, the PR can't be merged, so it looks like it got closed.