With package.json "exports" resolve paths deeply with conditional rules

[alshdavid]

Details

I am trying to use the exports in my package.json to deeply resolve module paths on top of a base path.

Essentially I have this folder structure:

./my-pkg
└── dist
   └── cjs
      ├── foo
      │  ├── bar
      │  │  └── index.js
      │  └── index.js
      └── index.js

And I would like node to be able to resolve the paths above as if they were /

console.log(require('my-pkg'))          // my-pkg/dist/cjs/index.js
console.log(require('my-pkg/foo'))      // my-pkg/dist/cjs/foo/index.js
console.log(require('my-pkg/foo/bar'))  // my-pkg/dist/cjs/foo/bar/index.js

The basic implementation of exports works for resolving the top level files (except the types keyword isn't being picked up by TypeScript 4.7, but that's another battle for another day):

{
  "exports": {
    ".": {
      "types": "./dist/types/index.d.ts",
      "import": "./dist/esm/index.js",
      "require": "./dist/cjs/index.js"
    }
  },
  ...
}

This allows me to import the following without issue

console.log(require('my-pkg'))  // my-pkg/dist/cjs/index.js

In the Node documentation it describes using * to add conditional resolution:

{
  ".": {
    "types": "./dist/types/index.d.ts",
    "import": "./dist/esm/index.js",
    "require": "./dist/cjs/index.js"
  },
  "./*": {
    "types": "./dist/types/*/index.d.ts",
    "import": "./dist/esm/*/index.js",
    "require": "./dist/cjs/*/index.js"
  }
},

console.log(require('my-pkg'))          // works
console.log(require('my-pkg/foo'))      // works
console.log(require('my-pkg/foo/bar'))  // does not work

This doesn't allow paths nested beyond ./*/. I have experimented with glob patterns like below but had no luck

{
  ".": {
    "types": "./dist/types/index.d.ts",
    "import": "./dist/esm/index.js",
    "require": "./dist/cjs/index.js"
  },
  "./**/*": {
    "types": "./dist/types/**/*",
    "import": "./dist/esm/**/*",
    "require": "./dist/cjs/**/*"
  }
},

I could explicitly add each nested path into exports manually but I would much prefer deep folder/file resolution be handled by node directly.

Any idea what I need to do to get this working?

Node.js version

Not applicable.

Example code

No response

Operating system

All

Scope

Module resolution

Module and version

Not applicable.

[gabzim]

Any help with this? having the same issue

[ljharb]

There is no solution besides doing it manually, for each level of nesting, i believe.

[alshdavid]

This (mostly) works:

{
  "name": "pkg",
  "exports": {
    "./": {
      "import": "./import/index.js",
      "require": "./require/index.js"
    },
    "./*": {
      "import": "./import/*",
      "require": ["./require/*", "./require/*.js", "./require/*/index.js"]
    }
  }
}

So from a CJS context:

const pkg = require('pkg')             /** resolves to */ 'node_modules/pkg/require/index.js'

const pkg = require('pkg/index')       /** resolves to */ 'node_modules/pkg/require/index'   
                                                /** or */ 'node_modules/pkg/require/index.js'
                                                /** or */ 'node_modules/pkg/require/index/index.js'

const pkg = require('pkg/index.js')    /** resolves to */ 'node_modules/pkg/require/index.js'

const pkg = require('pkg/foo.js')      /** resolves to */ 'node_modules/pkg/require/foo.js'

const pkg = require('pkg/foo')         /** resolves to */ 'node_modules/pkg/require/foo'    
                                                /** or */ 'node_modules/pkg/require/foo.js'
                                                /** or */ 'node_modules/pkg/require/foo/index.js'

const pkg = require('pkg/foo/bar')     /** resolves to */ 'node_modules/pkg/require/foo/bar' 
                                                /** or */ 'node_modules/pkg/require/foo/bar.js'
                                                /** or */ 'node_modules/pkg/require/foo/bar/index.js'

const pkg = require('pkg/foo/bar.js')  /** resolves to */ 'node_modules/pkg/require/foo/bar.js'

And from a MJS context:

import pkg from 'pkg'               /** resolves to */ 'node_modules/pkg/import/index.js'
import pkg from 'pkg/index'         /** not valid, requires extension */
import pkg from 'pkg/index.js'      /** resolves to */ 'node_modules/pkg/import/index.js'
import pkg from 'pkg/foo.js'        /** resolves to */ 'node_modules/pkg/import/foo.js'
import pkg from 'pkg/foo'           /** not valid, requires extension */
import pkg from 'pkg/foo/bar.js'    /** resolves to */ 'node_modules/pkg/import/foo/bar.js'

However Node accepts but only resolves the first item in an Array when supplied as a subpattern export.

I have raised a bug report to hopefully change that nodejs/node#49945

If that is updated, then the package.json config above will work as expected for nested patterns.

[alshdavid]

looks like there is a discussion on this here: nodejs/node#37928

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[github-actions]

It seems there has been no activity on this issue for a while, and it is being closed. If you believe this issue should remain open, please leave a comment.
If you need further assistance or have questions, you can also search for similar issues on Stack Overflow.
Make sure to look at the README file for the most updated links.