Help Codegen to find library's package.json after failure of importing library's package.json due to missing of ./package.json subpath

[RakaDoank]

Summary:

This is fix for some React Native libraries can't be found by Codegen, and will make the libraries unusable in new architecture (Turbo Modules)

Internally in the Codegen script, it will try to import library's package.json file with the require.resolve, but for some React Native libraries will throw an error with ERR_PACKAGE_PATH_NOT_EXPORTED code due to using the exports field in their package.json file while not exposing the package.json file itself. As an example

{
  "exports": {
    ".": {
      "import": {
        "types": "./lib/typescript/module/index.d.ts",
        "default": "./lib/module/index.js"
      },
      "require": {
        "types": "./lib/typescript/commonjs/index.d.ts",
        "default": "./lib/commonjs/index.js"
      }
    },
    "./package.json": "./package.json" <-- here some libraries missed this
  },
  "codegenConfig": {}
}

Personally feel weird that library author has to expose their package.json only for the sake of Codegen and i believe library author shouldn't, even the library consumer don't need it.

Changelog:

[GENERAL] [FIXED] - Help Codegen find library's package.json if some libraries using exports field in their package.json file and the ./package.json subpath is not explicitly defined

Test Plan:

require.resolve('library/package.json') here will throw an error with ERR_PACKAGE_PATH_NOT_EXPORTED code by Node.js. So if it does, help Codegen retry to find closest library's package.json with require.main.paths search paths

You can init new app React Native CLI app with my sample react native library here ping-react-native v1.2.2.
Due to missing of the package.json subpath, before this change, it's autolinked but unusable due to missing of the spec header file. After this change, it works normally.

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[cipolleschi]

@RakaDoank Thanks for the fix, this is amazing.!

[facebook-github-bot]

@cipolleschi has imported this pull request. If you are a Meta employee, you can view this in D79993649.

[facebook-github-bot]

@cipolleschi merged this pull request in 8dcb18d.

[react-native-bot]

This pull request was successfully merged by @RakaDoank in 8dcb18d

^{When will my fix make it into a release? | How to file a pick request?}

[cortinico]

This is currently breaking CI on main:
https://github.com/facebook/react-native/actions/runs/16888010481/job/47840881260

We'll have to revert it an get this PR back again with the proper fix

[facebook-github-bot]

This pull request has been reverted by 677ee67.