Offer `interface` keyword for classes in IntelliSense

[psfinaki]

Where is my interface keyword?

The word shows up, however, if there is something else out there:

[psfinaki]

Don't know if this has ever worked, not marking this is a bug or regression therefore.

@auduchinok might be related to parser recovery so something interesting for you? I remember a few PRs in this area but the above repros in the latest main.

[auduchinok]

Looking at the screenshots, it seems that in the first case the parser has recovered on the unfinished type declaration (look at the highlighted identifiers (i.e. they were analyzed after parsing), and on the second screenshot the whole analysis is broken (likely due to insufficient parser recovery, which indeed is interesting for me).

If this used to work previously, it may be that this code completion rule was written with an assumption of a broken tree. In that case the rule should be updated after the parser changes. I'm not familiar with the keywords code completion rules in Visual Studio or FCS, and I think currently @kerams is the most proficient with completion rules in FCS, so it might be something interesting for them too. 🙂

[psfinaki]

Hmm sooo I dag up an old version of VS (like, last year or so) - this reproduces, hence most likely it never worked.

[inosik]

FWIW, this works in VS 2019:

[psfinaki]

Hah, interesting. Thanks, good to know. So regression it is, although probably a long time regression.