Typescript: No watch file when extraFileExtensions on WatchCompilerHost

[yoyo930021]

TypeScript Version: 3.9 up

Search Terms:
extraFileExtensions, WatchCompilerHost, vue

Code
https://github.com/yoyo930021/TypeScript/blob/970d435c8d5848a369b5516a5e597f63f50afae6/src/testRunner/unittests/tscWatch/watchApi.ts#L127
The code is a test about this.
When filename ends with ts, It is pass,
but filename ends with vue, it isn't pass.

Expected behavior:
The test is pass.

Actual behavior:
The test is not pass.

Playground Link:
No

Related Issues:
No

The typescript-eslint tool is broken when vue with typescript 3.9.
The @sheetalkamat add a PR to fix it in https://github.com/microsoft/TypeScript/pull/37726.
But this PR is only work in startup.
When we add a new file, The WatchCompilerHost isn't watch this.

ref: https://github.com/typescript-eslint/typescript-eslint/issues/2127

[sheetalkamat]

I dont understand this issue. We have a test https://github.com/yoyo930021/TypeScript/blob/970d435c8d5848a369b5516a5e597f63f50afae6/src/testRunner/unittests/tscWatch/watchApi.ts#L156 as you pointed out that passes where new .vue file is detected and added to the program

[sheetalkamat]

Oh Sorry about that. i thought the test you pointed is already in there so thats where confusion came from.

[yoyo930021]

Thanks @sheetalkamat @RyanCavanaugh .
I tested well with typescript-eslint and Vue files.
When will this fix be released?

[sheetalkamat]

@DanielRosenwasser can we pick this for 4.1 ?

[DanielRosenwasser]

If you already merged it into master, it already has been 😅