Content mappers: a relative package path loads the package.json of the nearest folder with node_modules #65097

🔎 Search Terms

content mapper, contentMappers, package, relative path, TS18077, TS18075

🕗 Version & Regression Information

• 7.1.0-beta and 7.1.0-dev.20261101.1
• Content mappers are new in 7.1, so this isn't a regression.

⏯ Playground Link

Repro: https://github.com/onmax/repros/tree/repro/typescript-content-mapper-relative-package/typescript-content-mapper-relative-package

git clone --branch repro/typescript-content-mapper-relative-package https://github.com/onmax/repros
cd repros/typescript-content-mapper-relative-package
pnpm install && pnpm verify

💻 Code

// project/tsconfig.json, beside mapper/, which has a package.json named "txt-mapper"
{
  "contentMappers": [{ "package": "../mapper", "extensions": [".txt"] }]
}

🙁 Actual behavior

project/tsconfig.json(3,35): error TS18077: The 'package.json' of the content mapper package '../mapper' does not specify a 'name'.

The package.json it read is the fixture root's, which has no name. "../does-not-exist" gives the same error. When that folder's package.json declares a content mapper, as in a package's own tests, that mapper runs without any error.

🙂 Expected behavior

Either ../mapper resolves against the tsconfig's folder and loads mapper/, or it fails with TS18075 because only package names are supported.

Additional information about the issue

resolveContentMapperManifest passes the field to ResolvePackageDirectory. ParsePackageName returns .. as the package name, so the check that the package folder exists becomes DirectoryExists("<dir>/node_modules/.."), which passes in the first ancestor with a node_modules. The rest of the path is never read.

The same mapper referenced as "package": "txt-mapper" works; the repro checks both.