Fix isProgramUptoDate when changing rootFileNames

[yacinehmito]

Fixes #36010

I don't know what tests to write to validate that fix

I'll try to see if the current tests run that codepath. In the meantime the fix is there and maybe it's good enough to be merged as-is.

[sheetalkamat]

please add test similar to https://github.com/microsoft/TypeScript/blob/master/src/testRunner/unittests/reuseProgramStructure.ts#L229 where rootNames change but the number of root names don't change.

[RyanCavanaugh]

Requesting changes per Sheetal's comments on test location. Thanks!

[yacinehmito]

Hello. I don't understand what is expected. The test highlighted doesn't seem to involve isProgramUptoDate. It checks whether the program is reused but the logic doesn't rely on isProgramUpToDate (as a matter of fact it doesn't even call it).

[yacinehmito]

I found which test to update. It was in the same file. Sorry.

TypeScript/src/testRunner/unittests/reuseProgramStructure.ts

Line 908 in 236012e

describe("unittests:: Reuse program structure:: isProgramUptoDate should return true when there is no change in compiler options and", () => {

[sheetalkamat]

@yacinehmito can you please update the test case so we can take this in. Thanks

[yacinehmito]

Yes. I'm swamped at work so I didn't have time to go back to this. Will do so before Monday. Thanks for the patience!

[yacinehmito]

@sheetalkamat I have added the tests. Thank you for your patience.