feat(lib): allow multiple entries

docs/config/build-options.md

@@ -111,10 +111,10 @@ Options to pass on to [@rollup/plugin-dynamic-import-vars](https://github.com/ro
 
 ## build.lib
 
-- **Type:** `{ entry: string, name?: string, formats?: ('es' | 'cjs' | 'umd' | 'iife')[], fileName?: string | ((format: ModuleFormat) => string) }`
+- **Type:** `{ entry: string | string[] | { [entryAlias: string]: string }, name?: string, formats?: ('es' | 'cjs' | 'umd' | 'iife')[], fileName?: string | ((format: ModuleFormat, entryName: string) => string) }`
 - **Related:** [Library Mode](/guide/build#library-mode)
 
-Build as a library. `entry` is required since the library cannot use HTML as entry. `name` is the exposed global variable and is required when `formats` includes `'umd'` or `'iife'`. Default `formats` are `['es', 'umd']`. `fileName` is the name of the package file output, default `fileName` is the name option of package.json, it can also be defined as function taking the `format` as an argument.
+Build as a library. `entry` is required since the library cannot use HTML as entry. `name` is the exposed global variable and is required when `formats` includes `'umd'` or `'iife'`. Default `formats` are `['es', 'umd']`. `fileName` is the name of the package file output, default `fileName` is the name option of package.json, it can also be defined as function taking the `format` and `entryAlias` as arguments.
 
 ## build.manifest
 

docs/guide/build.md

@@ -128,6 +128,7 @@ import { defineConfig } from 'vite'
 export default defineConfig({
   build: {
     lib: {
+      // Could also be a dictionary or array of multiple entry points
       entry: resolve(__dirname, 'lib/main.js'),
       name: 'MyLib',
       // the proper extensions will be added
@@ -185,6 +186,28 @@ Recommended `package.json` for your lib:
 }
 ```
 
+Or, if exposing multiple entry points:
+
+```json
+{
+  "name": "my-lib",
+  "type": "module",
+  "files": ["dist"],
+  "main": "./dist/my-lib.cjs",
+  "module": "./dist/my-lib.mjs",
+  "exports": {
+    ".": {
+      "import": "./dist/my-lib.mjs",
+      "require": "./dist/my-lib.cjs"
+    },
+    "./secondary": {
+      "import": "./dist/secondary.mjs",
+      "require": "./dist/secondary.cjs"
+    }
+  }
+}
+```
+
 ::: tip Note
 If the `package.json` does not contain `"type": "module"`, Vite will generate different file extensions for Node.js compatibility. `.js` will become `.mjs` and `.cjs` will become `.js`.
 :::

packages/vite/src/node/__tests__/build.spec.ts

@@ -20,6 +20,7 @@ describe('resolveLibFilename', () => {
         entry: 'mylib.js'
       },
       'es',
+      'myLib',
       resolve(__dirname, 'packages/name')
     )
 
@@ -33,6 +34,7 @@ describe('resolveLibFilename', () => {
         entry: 'mylib.js'
       },
       'es',
+      'myLib',
       resolve(__dirname, 'packages/name')
     )
 
@@ -45,6 +47,7 @@ describe('resolveLibFilename', () => {
         entry: 'mylib.js'
       },
       'es',
+      'myLib',
       resolve(__dirname, 'packages/name')
     )
 
@@ -58,6 +61,7 @@ describe('resolveLibFilename', () => {
         entry: 'mylib.js'
       },
       'es',
+      'myLib',
       resolve(__dirname, 'packages/noname')
     )
 
@@ -71,6 +75,7 @@ describe('resolveLibFilename', () => {
           entry: 'mylib.js'
         },
         'es',
+        'myLib',
         resolve(__dirname, 'packages/noname')
       )
     }).toThrow()
@@ -88,6 +93,7 @@ describe('resolveLibFilename', () => {
       const filename = resolveLibFilename(
         baseLibOptions,
         format,
+        'myLib',
         resolve(__dirname, 'packages/noname')
       )
 
@@ -107,10 +113,134 @@ describe('resolveLibFilename', () => {
       const filename = resolveLibFilename(
         baseLibOptions,
         format,
+        'myLib',
         resolve(__dirname, 'packages/module')
       )
 
       expect(expectedFilename).toBe(filename)
     }
   })
+
+  test('multiple entries with aliases', () => {
+    const libOptions: LibraryOptions = {
+      entry: {
+        entryA: 'entryA.js',
+        entryB: 'entryB.js'
+      }
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('entryA.mjs')
+    expect(fileName2).toBe('entryB.mjs')
+  })
+
+  test('multiple entries with aliases: custom filename function', () => {
+    const libOptions: LibraryOptions = {
+      entry: {
+        entryA: 'entryA.js',
+        entryB: 'entryB.js'
+      },
+      fileName: (format, entryAlias) =>
+        `custom-filename-function.${entryAlias}.${format}.js`
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('custom-filename-function.entryA.es.js')
+    expect(fileName2).toBe('custom-filename-function.entryB.es.js')
+  })
+
+  test('multiple entries with aliases: custom filename string', () => {
+    const libOptions: LibraryOptions = {
+      entry: {
+        entryA: 'entryA.js',
+        entryB: 'entryB.js'
+      },
+      fileName: 'custom-filename'
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('custom-filename.mjs')
+    expect(fileName2).toBe('custom-filename.mjs')
+  })
+
+  test('multiple entries as array', () => {
+    const libOptions: LibraryOptions = {
+      entry: ['entryA.js', 'entryB.js']
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('entryA.mjs')
+    expect(fileName2).toBe('entryB.mjs')
+  })
+
+  test('multiple entries as array: custom filename function', () => {
+    const libOptions: LibraryOptions = {
+      entry: ['entryA.js', 'entryB.js'],
+      fileName: (format, entryAlias) =>
+        `custom-filename-function.${entryAlias}.${format}.js`
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('custom-filename-function.entryA.es.js')
+    expect(fileName2).toBe('custom-filename-function.entryB.es.js')
+  })
+
+  test('multiple entries as array: custom filename string', () => {
+    const libOptions: LibraryOptions = {
+      entry: ['entryA.js', 'entryB.js'],
+      fileName: 'custom-filename'
+    }
+
+    const [fileName1, fileName2] = ['entryA', 'entryB'].map((entryAlias) =>
+      resolveLibFilename(
+        libOptions,
+        'es',
+        entryAlias,
+        resolve(__dirname, 'packages/name')
+      )
+    )
+
+    expect(fileName1).toBe('custom-filename.mjs')
+    expect(fileName2).toBe('custom-filename.mjs')
+  })
 })

packages/vite/src/node/build.ts

@@ -3,6 +3,7 @@ import path from 'node:path'
 import colors from 'picocolors'
 import type {
   ExternalOption,
+  InputOption,
   InternalModuleFormat,
   ModuleFormat,
   OutputOptions,
@@ -208,7 +209,7 @@ export interface LibraryOptions {
   /**
    * Path of library entry
    */
-  entry: string
+  entry: InputOption
   /**
    * The name of the exposed global variable. Required when the `formats` option includes
    * `umd` or `iife`
@@ -224,7 +225,7 @@ export interface LibraryOptions {
    * of the project package.json. It can also be defined as a function taking the
    * format as an argument.
    */
-  fileName?: string | ((format: ModuleFormat) => string)
+  fileName?: string | ((format: ModuleFormat, entryName: string) => string)
 }
 
 export type LibraryFormats = 'es' | 'cjs' | 'umd' | 'iife'
@@ -373,7 +374,17 @@ async function doBuild(
 
   const resolve = (p: string) => path.resolve(config.root, p)
   const input = libOptions
-    ? options.rollupOptions?.input || resolve(libOptions.entry)
+    ? options.rollupOptions?.input ||
+      (typeof libOptions.entry === 'string'
+        ? resolve(libOptions.entry)
+        : Array.isArray(libOptions.entry)
+        ? libOptions.entry.map(resolve)
+        : Object.fromEntries(
+            Object.entries(libOptions.entry).map(([alias, file]) => [
+              alias,
+              resolve(file)
+            ])
+          ))
     : typeof options.ssr === 'string'
     ? resolve(options.ssr)
     : options.rollupOptions?.input || resolve('index.html')
@@ -470,7 +481,8 @@ async function doBuild(
         entryFileNames: ssr
           ? `[name].${jsExt}`
           : libOptions
-          ? resolveLibFilename(libOptions, format, config.root, jsExt)
+          ? ({ name }) =>
+              resolveLibFilename(libOptions, format, name, config.root, jsExt)
           : path.posix.join(options.assetsDir, `[name].[hash].${jsExt}`),
         chunkFileNames: libOptions
           ? `[name].[hash].${jsExt}`
@@ -620,15 +632,20 @@ function resolveOutputJsExtension(
 export function resolveLibFilename(
   libOptions: LibraryOptions,
   format: ModuleFormat,
+  entryName: string,
   root: string,
   extension?: JsExt
 ): string {
   if (typeof libOptions.fileName === 'function') {
-    return libOptions.fileName(format)
+    return libOptions.fileName(format, entryName)
   }
 
   const packageJson = getPkgJson(root)
-  const name = libOptions.fileName || getPkgName(packageJson.name)
+  const name =
+    libOptions.fileName ||
+    (typeof libOptions.entry === 'string'
+      ? getPkgName(packageJson.name)
+      : entryName)
 
   if (!name)
     throw new Error(
@@ -651,14 +668,22 @@ function resolveBuildOutputs(
 ): OutputOptions | OutputOptions[] | undefined {
   if (libOptions) {
     const formats = libOptions.formats || ['es', 'umd']
-    if (
-      (formats.includes('umd') || formats.includes('iife')) &&
-      !libOptions.name
-    ) {
-      throw new Error(
-        `Option "build.lib.name" is required when output formats ` +
-          `include "umd" or "iife".`
-      )
+    if (formats.includes('umd') || formats.includes('iife')) {
+      if (
+        typeof libOptions.entry !== 'string' &&
+        Object.values(libOptions.entry).length > 1
+      ) {
+        throw new Error(
+          `Multiple entry points are not supported when output formats include "umd" or "iife".`
+        )
+      }
+
+      if (!libOptions.name) {
+        throw new Error(
+          `Option "build.lib.name" is required when output formats ` +
+            `include "umd" or "iife".`
+        )
+      }
     }
     if (!outputs) {
       return formats.map((format) => ({ format }))