ModuleResolution Node16/NodeNext fails without extension starting on 5.5.0-dev.20240413

[Noriller]

🔎 Search Terms

moduleResolution node16 nodeNext import extension

🕗 Version & Regression Information

• This changed between versions 5.5.0-dev.20240413 and 5.5.0-dev.20240415 (last one checked)

⏯ Playground Link

No response

💻 Code

type Something1 = typeof import('@some/package/path/to/file');
type Something2 = typeof import('@some/package/path/to/file.js');

🙁 Actual behavior

Something1 resolves to any
Something2 resolves to Something

🙂 Expected behavior

Something1 resolves to Something
Something2 resolves to Something

Additional information about the issue

This happens on the latest nightly versions and on moduleResolution Node16/NodeNext.

From what I could get, it started on 5.5.0-dev.20240413.

[RyanCavanaugh]

We need a complete repro here; the package.json of @some/package, its contents, the importing package, and the tsconfig for the importing file all matter

[Noriller]

https://stackblitz.com/~/github.com/Noriller/ts-issue-58214

I hope this one helps.

In the test.d.ts with the current typescript@next and same jsconfig (its a legacy project, using mostly jsdocs, but with the problem in a d.ts file)

If changing ts version with:

npm i -D typescript@5.5.0-dev.20240412

then both work

[jakebailey]

This bisects to #57896. @andrewbranch

(I'm not an expert, but it seems strange that you'd need an extension when the d.ts file is effectively CJS, importing another CJS file, but importing via a JS file is already funky.)

[andrewbranch]

Guessing I accidentally made ImportTypes look like an ESM-mode source location, when they were previously kept CJS-mode for backward compatibility reasons. Will take a look. Thanks!