Typescript support for moduleResolution node16

[k2snowman69]

As a typescript user when setting moduleResolution to Node16 or NodeNext, I currently get typescript failures from the ignore package.

Due to typescript-eslint@6 upgrading to only support Node16+, I'm unable to support both simultaneously.

For more information on possible fixes see:
https://arethetypeswrong.github.io/?p=ignore

[kaelzhang]

Could you provide the use cases or concrete code slices?

Is it only a linting warning about potential issues or are there any real failures?

Here is the test case only for ts definition: https://github.com/kaelzhang/node-ignore/blob/master/test/ts/simple.ts

[k2snowman69]

Sure and it's a real typescript typing/intellisense failure, not just linting. I ran into this in my own project here:
https://github.com/snowcoders/sortier/pull/2226/files#diff-55dee8ec3daf30391537fdc45f8c2639cca5d3e63faf83671ee7505eeb8fed03R10

I think with typescript + node16 resolution, when you share a single types file with cjs and esm, it seems to assume cjs. In this code, I had to @ts-expect-error because ignore here was the import module and typescript wanted me to use ignore.default(). Obviously that doesn't match your build output so I had to ignore the error to be able to get the program to continue to run.

If you need a repo environment, that project should work, just removed the @ts-expect-error and you should see the same bug. If that doesn't work for you, creating a narrowed reproduction repo wouldn't be difficult, it will just take a few days since the work week is starting.

[kaelzhang]

It is really weird that tsc treats packages with/without type: module differently.

• ❌ tsc ./src/lib/is-ignored/index.ts --moduleResolution Node16 failed with type:module in package.json
• ✅ tsc ./src/lib/is-ignored/index.ts --moduleResolution Node16 succeeded with no type:module in package.json
• ✅ tsc ./src/lib/is-ignored/index.ts succeeded

[guoyunhe]

@kaelzhang I think the only way to fix this is to add a real esm output:

{
  "name": "ignore",
  "version": "5.3.0",
  "main": "index.js",
  "module": "index.mjs",
  "types": "index.d.ts"
}