TypeScript diagnostics gets corrupted after typing Map

[bpasero]

Latest insider broke TS entirely for me. When writing a typed Map I get errors out of nowhere:

[mjbvz]

Here's a TS Server log of this happening:

tsserver-log-Y1xK2u.zip

I reproduce this in the VS Code codebase by typing out private map = new Map<string, number>() in a class. This corrupted the diagnostics. A few seconds later I ran format and the document was incorrectly formatted

[andrewbranch]

Possibly an incremental parsing bug? Probably best to start with a bisect and go from there.

[DanielRosenwasser]

First appears in [email protected] from what I can tell.

//// class C {
////     map = new Set<string, number>/*$*/
////
////     foo() {
////
////     }
//// }

Insert () at the /*$*/ marker and expect no errors.

[DanielRosenwasser]

Looking at this search query, this was likely caused by #43005

[DanielRosenwasser]

If we can, we should try to back-port this to 4.6.

[DanielRosenwasser]

I've kicked off a task to cherry-pick the fix to release-4.6 - unfortunately, 4.6 is already out. 😅

If there's a VS Code servicing release, maybe we can aim for a 4.6.3 patch release before then. Otherwise, it would still be nice to get this in before 4.7.