feat(build): emit license

docs/config/build-options.md

@@ -185,6 +185,71 @@ export default defineConfig({
 })
 ```
 
+## build.license
+
+- **Type:** `boolean | { fileName?: string }`
+- **Default:** `false`
+
+When set to `true`, the build will generate a `.vite/license.md` file that includes all bundled dependencies' licenses. It can be hosted to display and acknowledge the dependencies used by the app. When `fileName` is passed, it will be used as the license file name relative to the `outDir`. An example output may look like this:
+
+```md
+# Licenses
+
+The app bundles dependencies which contain the following licenses:
+
+## dep-1 - 1.2.3 (CC0-1.0)
+
+CC0 1.0 Universal
+
+...
+
+## dep-2 - 4.5.6 (MIT)
+
+MIT License
+
+...
+```
+
+If the `fileName` ends with `.json`, the raw JSON metadata will be generated instead and can be used for further processing. For example:
+
+```json
+[
+  {
+    "name": "dep-1",
+    "version": "1.2.3",
+    "identifier": "CC0-1.0",
+    "text": "CC0 1.0 Universal\n\n..."
+  },
+  {
+    "name": "dep-2",
+    "version": "4.5.6",
+    "identifier": "MIT",
+    "text": "MIT License\n\n..."
+  }
+]
+```
+
+::: tip
+If you'd like to reference the license file in the built code, you can use `build.rollupOptions.output.banner` to inject a comment at the top of the files. For example:
+
+```js twoslash [vite.config.js]
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  build: {
+    license: true,
+    rollupOptions: {
+      output: {
+        banner:
+          '/* See licenses of bundled dependencies at https://example.com/license.md */',
+      },
+    },
+  },
+})
+```
+
+:::
+
 ## build.manifest
 
 - **Type:** `boolean | string`

packages/vite/src/node/__tests__/plugins/__snapshots__/license.spec.ts.snap

@@ -0,0 +1,47 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`json 1`] = `
+"[
+  {
+    "name": "@vitejs/test-dep-licence-cc0",
+    "version": "0.0.0",
+    "identifier": "CC0-1.0",
+    "text": "CC0 1.0 Universal\\n\\n..."
+  },
+  {
+    "name": "@vitejs/test-dep-license-mit",
+    "version": "0.0.0",
+    "identifier": "MIT",
+    "text": "MIT License\\n\\nCopyright (c) ..."
+  },
+  {
+    "name": "@vitejs/test-dep-nested-license-isc",
+    "version": "0.0.0",
+    "identifier": "ISC",
+    "text": "Copyright (c) ..."
+  }
+]"
+`;
+
+exports[`markdown 1`] = `
+"# Licenses
+
+The app bundles dependencies which contain the following licenses:
+
+## @vitejs/test-dep-licence-cc0 - 0.0.0 (CC0-1.0)
+
+CC0 1.0 Universal
+
+...
+
+## @vitejs/test-dep-license-mit - 0.0.0 (MIT)
+
+MIT License
+
+Copyright (c) ...
+
+## @vitejs/test-dep-nested-license-isc - 0.0.0 (ISC)
+
+Copyright (c) ...
+"
+`;

packages/vite/src/node/__tests__/plugins/esbuild.spec.ts

@@ -23,7 +23,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'es',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: 'es2020',
       format: 'esm',
@@ -67,7 +66,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'es',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: undefined,
       format: 'esm',
@@ -98,7 +96,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'es',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: 'es2020',
       format: 'esm',
@@ -131,7 +128,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'es',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: undefined,
       format: 'esm',
@@ -164,7 +160,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'cjs',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: undefined,
       format: 'cjs',
@@ -196,7 +191,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'es',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: undefined,
       format: 'esm',
@@ -232,7 +226,6 @@ describe('resolveEsbuildTranspileOptions', () => {
       'cjs',
     )
     expect(options).toEqual({
-      charset: 'utf8',
       loader: 'js',
       target: undefined,
       format: 'cjs',

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-licence-cc0/index.js

@@ -0,0 +1 @@
+export default 'ok'

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-licence-cc0/licence

@@ -0,0 +1,3 @@
+CC0 1.0 Universal
+
+...

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-licence-cc0/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "@vitejs/test-dep-licence-cc0",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "license": "CC0-1.0"
+}

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-license-mit/index.js

@@ -0,0 +1,3 @@
+import nestedDep from '@vitejs/test-dep-nested-license-isc'
+
+export default 'ok' + nestedDep

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-license-mit/license

@@ -0,0 +1,3 @@
+MIT License
+
+Copyright (c) ...

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-license-mit/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "@vitejs/test-dep-license-mit",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "license": "MIT",
+  "dependencies": {
+    "@vitejs/test-dep-nested-license-isc": "file:../dep-nested-license-isc"
+  }
+}

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-nested-license-isc/LICENSE

@@ -0,0 +1 @@
+Copyright (c) ...

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-nested-license-isc/index.js

@@ -0,0 +1 @@
+export default 'ok'

packages/vite/src/node/__tests__/plugins/fixtures/license/dep-nested-license-isc/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "@vitejs/test-dep-nested-license-isc",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "license": "ISC"
+}

packages/vite/src/node/__tests__/plugins/fixtures/license/index.html

@@ -0,0 +1,5 @@
+<script type="module">
+  import dep1 from '@vitejs/test-dep-licence-cc0'
+  import dep2 from '@vitejs/test-dep-license-mit'
+  console.log(dep1, dep2)
+</script>

packages/vite/src/node/__tests__/plugins/fixtures/license/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "@vitejs/test-license",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "dependencies": {
+    "@vitejs/test-dep-license-mit": "file:./dep-license-mit",
+    "@vitejs/test-dep-licence-cc0": "file:./dep-licence-cc0"
+  }
+}

packages/vite/src/node/__tests__/plugins/license.spec.ts

@@ -0,0 +1,38 @@
+import { fileURLToPath } from 'node:url'
+import type { OutputAsset, RollupOutput } from 'rollup'
+import { expect, test } from 'vitest'
+import { build } from '../../build'
+
+test('markdown', async () => {
+  const result = (await build({
+    root: fileURLToPath(new URL('./fixtures/license', import.meta.url)),
+    logLevel: 'silent',
+    build: {
+      write: false,
+      license: true,
+    },
+  })) as RollupOutput
+  const licenseAsset = result.output.find(
+    (asset) => asset.fileName === '.vite/license.md',
+  ) as OutputAsset | undefined
+  expect(licenseAsset).toBeDefined()
+  expect(licenseAsset?.source).toMatchSnapshot()
+})
+
+test('json', async () => {
+  const result = (await build({
+    root: fileURLToPath(new URL('./fixtures/license', import.meta.url)),
+    logLevel: 'silent',
+    build: {
+      write: false,
+      license: {
+        fileName: '.vite/license.json',
+      },
+    },
+  })) as RollupOutput
+  const licenseAsset = result.output.find(
+    (asset) => asset.fileName === '.vite/license.json',
+  ) as OutputAsset | undefined
+  expect(licenseAsset).toBeDefined()
+  expect(licenseAsset?.source).toMatchSnapshot()
+})

packages/vite/src/node/build.ts

@@ -71,6 +71,7 @@ import { getHookHandler } from './plugins'
 import { BaseEnvironment } from './baseEnvironment'
 import type { MinimalPluginContextWithoutEnvironment, Plugin } from './plugin'
 import type { RollupPluginHooks } from './typeUtils'
+import { type LicenseOptions, licensePlugin } from './plugins/license'
 import {
   BasicMinimalPluginContext,
   basePluginContextMeta,
@@ -209,6 +210,12 @@ export interface BuildEnvironmentOptions {
    * @default true
    */
   copyPublicDir?: boolean
+  /**
+   * Whether to emit a `.vite/license.md` file that includes all bundled dependencies'
+   * licenses. Pass an object to customize the output file name.
+   * @default false
+   */
+  license?: boolean | LicenseOptions
   /**
    * Whether to emit a .vite/manifest.json in the output dir to map hash-less filenames
    * to their hashed versions. Useful when you want to generate your own HTML
@@ -380,6 +387,7 @@ const _buildEnvironmentOptionsDefaults = Object.freeze({
   write: true,
   emptyOutDir: null,
   copyPublicDir: true,
+  license: false,
   manifest: false,
   lib: false,
   // ssr
@@ -495,7 +503,12 @@ export async function resolveBuildPlugins(config: ResolvedConfig): Promise<{
       buildEsbuildPlugin(),
       terserPlugin(config),
       ...(!config.isWorker
-        ? [manifestPlugin(), ssrManifestPlugin(), buildReporterPlugin(config)]
+        ? [
+            licensePlugin(),
+            manifestPlugin(),
+            ssrManifestPlugin(),
+            buildReporterPlugin(config),
+          ]
         : []),
       buildLoadFallbackPlugin(),
     ],

packages/vite/src/node/config.ts

@@ -1518,6 +1518,9 @@ export async function resolveConfig(
         ? false
         : {
             jsxDev: !isProduction,
+            // change defaults that fit better for vite
+            charset: 'utf8',
+            legalComments: 'none',
             ...config.esbuild,
           },
     server,

packages/vite/src/node/optimizer/index.ts

@@ -858,6 +858,7 @@ async function prepareEsbuildOptimizerRun(
     metafile: true,
     plugins,
     charset: 'utf8',
+    legalComments: 'none',
     ...esbuildOptions,
     supported: {
       ...defaultEsbuildSupported,

packages/vite/src/node/plugins/css.ts

@@ -2194,7 +2194,7 @@ function resolveMinifyCssEsbuildOptions(
   options: ESBuildOptions,
 ): TransformOptions {
   const base: TransformOptions = {
-    charset: options.charset ?? 'utf8',
+    charset: options.charset,
     logLevel: options.logLevel,
     logLimit: options.logLimit,
     logOverride: options.logOverride,

packages/vite/src/node/plugins/define.ts

@@ -199,7 +199,7 @@ export async function replaceDefine(
 
   const result = await transform(code, {
     loader: 'js',
-    charset: esbuildOptions.charset ?? 'utf8',
+    charset: esbuildOptions.charset,
     platform: 'neutral',
     define,
     sourcefile: id,

packages/vite/src/node/plugins/esbuild.ts

@@ -249,7 +249,6 @@ export function esbuildPlugin(config: ResolvedConfig): Plugin {
   // and for build as the final optimization is in `buildEsbuildPlugin`
   const transformOptions: TransformOptions = {
     target: 'esnext',
-    charset: 'utf8',
     ...esbuildTransformOptions,
     minify: false,
     minifyIdentifiers: false,
@@ -403,7 +402,6 @@ export function resolveEsbuildTranspileOptions(
   const esbuildOptions = config.esbuild || {}
 
   const options: TransformOptions = {
-    charset: 'utf8',
     ...esbuildOptions,
     loader: 'js',
     target: target || undefined,