Package.json star and directory exports not working

Describe the bug

The newly introduced package.json exports field explicitly defines the exports map for a library.

• When describing exports as a directory map, it should forward dependency resolution to the classic resolution mechanism, but it does not.
  • Given the export "./mydir/": { "import": "./build/mydir/" }
  • Vite.js should be able to resolve package/mydir/nested/path to package/build/mydir/nested/path.js or package/build/mydir/nested/path/index.js but it fails.
• WebPack also introduced star exports, that allow you to resolve nested exports to specific file types.
  • Given the export: "./mydir/*": { "import": "./build/mydir/*/*.js" }
  • Vite.js should be able to resolve /mydir/nested/path to package/build/mydir/nested/path.js but it fails.

Reproduction

1. npm init @vitejs/app
2. npm install @inkline/icons
3. Edit node_modules/@inkline/icons/package.json in place and add the following:

  "exports": {
    ".": {
      "import": "./build/index.js"
    },
    "./packs": {
      "import": "./build/packs/index.js"
    },
    "./packs/": {
      "import": "./build/packs/"
    },
    "./helpers/*": {
      "import": "./build/helpers/*.js"
    }
  },

1. Edit src/main.ts and add the following:

import { toCamelCase } from '@inkline/icons/helpers';
import { fasHome } from '@inkline/icons/packs/fontawesome';
import { inkCheck } from '@inkline/icons/packs/inkline';

console.log(toCamelCase, fasHome, inkCheck);

1. npm run dev

System Info

Output of npx envinfo --system --npmPackages vite,@vitejs/plugin-vue --binaries --browsers:

  System:
    OS: macOS 10.15.4
    CPU: (4) x64 Intel(R) Core(TM) i5-6600 CPU @ 3.30GHz
    Memory: 53.07 MB / 32.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 14.16.0 - ~/.nvm/versions/node/v14.16.0/bin/node
    npm: 6.14.11 - ~/.nvm/versions/node/v14.16.0/bin/npm
  Browsers:
    Chrome: 90.0.4430.212
    Firefox: 75.0
    Safari: 13.1
  npmPackages:
    @vitejs/plugin-vue: ^1.2.2 => 1.2.2 
    vite: ^2.3.0 => 2.3.2 

Used package manager: npm

Logs

For directory exports:

> vite-project@0.0.0 dev /Users/alexgrozav/Workspace/vite-project
> vite

error when starting dev server:
Error: The following dependencies are imported but could not be resolved:

  @inkline/icons/packs/fontawesome (imported by /Users/alexgrozav/Workspace/vite-project/src/main.ts)

Are they installed?
    at optimizeDeps (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:64623:15)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at async runOptimize (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:68436:48)
    at async Server.httpServer.listen (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:68450:17)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vite-project@0.0.0 dev: `vite`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the vite-project@0.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/alexgrozav/.npm/_logs/2021-05-14T06_26_12_449Z-debug.log

For star exports:

> vite-project@0.0.0 dev /Users/alexgrozav/Workspace/vite-project
> vite

 > node_modules/vite/dist/node/chunks/dep-efbff8d5.js:31957:7: error: [plugin: vite:dep-scan] Missing "./helpers" export in "@inkline/icons" package
    31957 │   throw new Error(
          ╵         ^
    at bail (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:31957:8)
    at resolve$1 (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:32033:10)
    at resolveExports (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:32462:12)
    at resolveDeepImport (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:32479:26)
    at tryNodeResolve (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:32268:11)
    at Context.resolveId (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:32152:28)
    at Object.resolveId (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44098:55)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)
    at async resolve (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44294:26)
    at async /Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44402:34

   node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44392:18: note: This error came from the "onResolve" callback registered here
    44392 │             build.onResolve({
          ╵                   ~~~~~~~~~
    at setup (/Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44392:19)
    at handlePlugins (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:733:23)
    at Object.buildOrServe (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1018:7)
    at /Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1742:17
    at new Promise (<anonymous>)
    at Object.build (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1741:14)
    at Object.build (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1617:51)
    at /Users/alexgrozav/Workspace/vite-project/node_modules/vite/dist/node/chunks/dep-efbff8d5.js:44255:54
    at Array.map (<anonymous>)

   src/main.ts:2:28: note: The plugin "vite:dep-scan" was triggered by this import
        2 │ import { toCamelCase } from '@inkline/icons/helpers';
          ╵                             ~~~~~~~~~~~~~~~~~~~~~~~~

error when starting dev server:
Error: Build failed with 1 error:
node_modules/vite/dist/node/chunks/dep-efbff8d5.js:31957:7: error: [plugin: vite:dep-scan] Missing "./helpers" export in "@inkline/icons" package
    at failureErrorWithLog (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1443:15)
    at /Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1125:28
    at runOnEndCallbacks (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:915:63)
    at buildResponseToResult (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1123:7)
    at /Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:1230:14
    at /Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:606:9
    at handleIncomingPacket (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:703:9)
    at Socket.readFromStdout (/Users/alexgrozav/Workspace/vite-project/node_modules/esbuild/lib/main.js:573:7)
    at Socket.emit (events.js:315:20)
    at addChunk (internal/streams/readable.js:309:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vite-project@0.0.0 dev: `vite`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the vite-project@0.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/alexgrozav/.npm/_logs/2021-05-14T06_25_10_219Z-debug.log

---

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[sodatea]

Subpath folder mappings are deprecated in Node.js https://nodejs.org/api/packages.html#packages_subpath_patterns so I don’t think we should support it.

But yeah, subpath patterns should be supported.

[ignatiusmb]

I can confirm, even without exports map and just default directory traversal, modules exported with the following resolves to undefined.

// geometry/index.js
export * as shapes from './shapes';

// geometry/shapes/index.js
export function circle() {}
export function rect() {}
export function triangle() {}


// assume module is installed with npm
import { shapes } from 'module/geometry';
console.log(shapes); // undefined

import * as shapes from 'module/geometry/shapes';
console.log(shapes); // works -> { circle: [Getter], rect: [Getter], triangle: [Getter] }

Directory structure for example above

module
│
└───geometry
      ├──shapes
      │     └──index.js
      │
      └──index.js

Edit: This will be a problem when library authors only exposes ./geometry in the exports map and essentially locking the imports. This means users can’t directly import from module/geometry/shapes because it’s not defined in the exports.