tsconfig "extends" field ignores "exports" field of source package

[pschiffmann]

Bug Report

🔎 Search Terms

tsconfig, exports, extends

🕗 Version & Regression Information

I encountered this issue in version typescript@4.7.0-dev.20220408.

Error description

You can use the tsconfig.json extends field to inherit configuration options from another tsconfig file. The base tsconfig file can be located in another package, like demonstrated here.

🙁 Actual behavior

Let's say I'm in package my-app, which contains a tsconfig with "extends": "my-lib/tsconfig-base.json. Typescript ignores the exports field of package my-lib. It will always look for a file tsconfig-base.json in the my-lib root directory, even if an "exports" mapping exists for this name.

🙂 Expected behavior

I expected Typescript to use the standard node resolution algorithm when looking up the tsconfig file on disk, which respects the "exports" field.

[weswigham]

getExtendsConfigPath in commandLineParser.ts is currently using nodeModuleNameResolver and passing { moduleResolution: ModuleResolutionKind.NodeJs } - it should just need to be swapped to nodeNextModuleNameResolver and pass { moduleResolution: ModuleResolutionKind.NodeNext }, and hopefully it should just work. Definitely needs some tests to check that tsconfig.json documents resolve through exports when searched for in this way, though, since it hasn;t been utilized with that Extensions set much yet. Should be an easy change for anyone to make~