[regression - 5.4] Generated `.d.ts` file contains invalid types about typescript

[jakebailey]

If you hadn't tried it yet, https://www.npmjs.com/package/every-ts can bisect further down from the nightly versions.

[bradzacher]

Bisecting with every-ts reveals 4bcbc16 to be the bad commit (#56087)

[bradzacher]

Update: This is a regression in TS5.4

In TS5.3 the emitted .d.ts file is correct, but in TS5.4 it uses the wrong type names

[bradzacher]

I've got a repro repo for testing too.

1. clone https://github.com/bradzacher/bug-repros
2. checkout the typescript-dts-emit-bug branch
3. npm i
4. npm test --> observe diff

Bisecting it looks like the first release that exhibited this bug was 5.4.0-dev.20240110 (it does not reproduce on 5.4.0-dev.20240109)

[bradzacher]

Yup - 100% confirmed.
4bcbc16 only has 4 lines of changes so it's easy to revert locally. If I comment out the 4 lines then it emits the correct output.

[bradzacher]

I patched #57396 locally and it looks like it fixes the regression