vite-magic-tree-shaking

Auto-generate tree-shakeable build.lib.entry for Vite from your source directory.

Install

npm install -D vite-magic-tree-shaking

Usage

// vite.config.ts
import { defineConfig } from 'vite'
import { fileURLToPath } from 'node:url'
import { generateEntries } from 'vite-magic-tree-shaking'

const __dirname = fileURLToPath(new URL('.', import.meta.url))

export default defineConfig({
  build: {
    lib: {
      entry: generateEntries(__dirname),       // scans src/ by default
      // entry: generateEntries(__dirname, 'lib'), // custom source dir
      formats: ['es'],
      fileName: (_, entryName) => `${entryName}.js`,
    },
    rollupOptions: {
      external: ['react', 'react-dom'],
      output: {
        preserveModules: true,
        preserveModulesRoot: 'src',
      },
    },
  },
})

Warn when package.json exports are out of sync

Pass warnOnExportsMismatch: true to get a console.warn at build/dev time if the exports field in package.json does not match the entries resolved from your source directory:

entry: generateEntries(__dirname, 'src', { warnOnExportsMismatch: true })

[vite-magic-tree-shaking] package.json exports are out of sync with src entries.
Run: npx vite-magic generate

CLI

The package ships a vite-magic binary with two commands.

generate

Reads your source directory, derives the entry map, and writes the matching exports field into package.json. Run this after adding or removing source files.

# using npx (no install required)
npx vite-magic generate

# custom rootDir and srcDir
npx vite-magic generate /path/to/project lib

Example output:

✓ package.json exports updated:
  .
  ./Button/Button
  ./Users
  ./Users/domain/user
  ./Users/types/UserDTO

validate

Checks that the exports field in package.json matches the entries derived from the source directory. Exits with code 1 if they are out of sync — useful in CI.

npx vite-magic validate

Example output when in sync:

✓ package.json exports are in sync

Example output when out of sync:

✗ package.json exports are out of sync with src entries
  Missing : ./NewFeature
  Extra   : ./OldFeature
  Changed : ./Users

Run: npx vite-magic generate

Add to package.json scripts

{
  "scripts": {
    "sync-exports": "vite-magic generate",
    "validate-exports": "vite-magic validate",
    "prebuild": "vite-magic validate"
  }
}

With prebuild wired up, running npm run build will abort with a clear error if package.json exports are stale, before Vite even starts.

How entries are resolved

Given this structure:

src/
├── index.ts
├── Users/
│   ├── index.ts
│   ├── domain/
│   │   └── user.ts
│   └── types/
│       └── UserDTO.ts
└── Button/
    └── Button.tsx

generateEntries(__dirname) produces:

{
  index:                 '/abs/src/index.ts',
  Users:                 '/abs/src/Users/index.ts',
  'Users/domain/user':   '/abs/src/Users/domain/user.ts',
  'Users/types/UserDTO': '/abs/src/Users/types/UserDTO.ts',
  'Button/Button':       '/abs/src/Button/Button.tsx',
}

And vite-magic generate writes the corresponding exports to package.json:

{
  "exports": {
    ".": {
      "types": "./dist/index.d.ts",
      "import": "./dist/index.js",
      "require": "./dist/index.cjs"
    },
    "./Users": {
      "types": "./dist/Users.d.ts",
      "import": "./dist/Users.js",
      "require": "./dist/Users.cjs"
    },
    "./Users/domain/user": {
      "types": "./dist/Users/domain/user.d.ts",
      "import": "./dist/Users/domain/user.js",
      "require": "./dist/Users/domain/user.cjs"
    },
    "./Users/types/UserDTO": {
      "types": "./dist/Users/types/UserDTO.d.ts",
      "import": "./dist/Users/types/UserDTO.js",
      "require": "./dist/Users/types/UserDTO.cjs"
    },
    "./Button/Button": {
      "types": "./dist/Button/Button.d.ts",
      "import": "./dist/Button/Button.js",
      "require": "./dist/Button/Button.cjs"
    }
  }
}

Rules

| Source | Entry key | |---|---| | src/index.ts | index | | src/Users/index.ts | Users | | src/Button/Button.tsx (no index in dir) | Button/Button | | src/Users/domain/user.ts (subdir of indexed dir) | Users/domain/user |

Directories with an index file use the directory name as key. Their subdirectories are still scanned recursively.

Directories without an index expose each file individually using its relative path (without extension).

Ignored files

The following are never included as entries:

• *.test.ts / *.spec.ts
• *.stories.tsx
• *.d.ts / *.d.mts / *.d.cts
• Any file with an extension other than .ts, .tsx, .js, .jsx, .mts, .cts

API

generateEntries(rootDir: string, srcDir?: string, options?: GenerateEntriesOptions): Record<string, string>

| Parameter | Type | Default | Description | |---|---|---|---| | rootDir | string | — | Absolute path to the project root | | srcDir | string | 'src' | Source directory name, relative to rootDir | | options | GenerateEntriesOptions | {} | Optional configuration |

GenerateEntriesOptions

| Option | Type | Default | Description | |---|---|---|---| | warnOnExportsMismatch | boolean | false | Emit a console.warn if package.json exports do not match the resolved entries |

License

MIT