feat!: the epic rolldown-vite merge

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -33,7 +33,7 @@ body:
     id: system-info
     attributes:
       label: System Info
-      description: Output of `npx envinfo --system --npmPackages '{vite,@vitejs/*,rollup}' --binaries --browsers`
+      description: Output of `npx envinfo --system --npmPackages '{vite,@vitejs/*,rollup,rolldown}' --binaries --browsers`
       render: shell
       placeholder: System, Binaries, Browsers
     validations:

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,8 @@
 blank_issues_enabled: false
 contact_links:
+  - name: Rolldown-Vite & Vite 8 beta Issues
+    url: https://github.com/vitejs/rolldown-vite/issues/new/choose
+    about: Rolldown-Vite related issues should be reported on the rolldown-vite repository.
   - name: Vite Plugin React Issues
     url: https://github.com/vitejs/vite-plugin-react/issues/new/choose
     about: React related issues should be reported on the vite-plugin-react repository.

.github/workflows/ci.yml

@@ -143,6 +143,78 @@ jobs:
     steps:
       - run: echo "Build & Test Failed"
 
+  test-js-plugins:
+    needs: changed
+    if: needs.changed.outputs.should_skip != 'true'
+    timeout-minutes: 20
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        node_version: [22]
+      fail-fast: false
+
+    name: "Build&Test: node-${{ matrix.node_version }}, ${{ matrix.os }} (js plugins)"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@a7487c7e89a18df4991f7f222e4898a00d66ddda # v4.1.0
+
+      - name: Set node version to ${{ matrix.node_version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node_version }}
+          cache: "pnpm"
+
+      - name: Install deps
+        run: pnpm install
+
+      # Install playwright's binary under custom directory to cache
+      - name: (non-windows) Set Playwright path and Get playwright version
+        if: runner.os != 'Windows'
+        run: |
+          echo "PLAYWRIGHT_BROWSERS_PATH=$HOME/.cache/playwright-bin" >> $GITHUB_ENV
+          PLAYWRIGHT_VERSION="$(pnpm ls --depth 0 --json -w playwright-chromium | jq --raw-output '.[0].devDependencies["playwright-chromium"].version')"
+          echo "PLAYWRIGHT_VERSION=$PLAYWRIGHT_VERSION" >> $GITHUB_ENV
+      - name: (windows) Set Playwright path and Get playwright version
+        if: runner.os == 'Windows'
+        run: |
+          echo "PLAYWRIGHT_BROWSERS_PATH=$HOME\.cache\playwright-bin" >> $env:GITHUB_ENV
+          $env:PLAYWRIGHT_VERSION="$(pnpm ls --depth 0 --json -w playwright-chromium | jq --raw-output '.[0].devDependencies["playwright-chromium"].version')"
+          echo "PLAYWRIGHT_VERSION=$env:PLAYWRIGHT_VERSION" >> $env:GITHUB_ENV
+
+      - name: Cache Playwright's binary
+        uses: actions/cache@v4
+        with:
+          key: ${{ runner.os }}-playwright-bin-v1-${{ env.PLAYWRIGHT_VERSION }}
+          path: ${{ env.PLAYWRIGHT_BROWSERS_PATH }}
+          restore-keys: |
+            ${{ runner.os }}-playwright-bin-v1-
+
+      - name: Install Playwright
+        # does not need to explicitly set chromium after https://github.com/microsoft/playwright/issues/14862 is solved
+        run: pnpm playwright install chromium
+
+      - name: Build
+        run: pnpm run build
+
+      - name: Test unit
+        run: pnpm run test-unit
+        env:
+          _VITE_TEST_JS_PLUGIN: 1
+
+      - name: Test serve
+        run: pnpm run test-serve
+        env:
+          _VITE_TEST_JS_PLUGIN: 1
+
+      - name: Test build
+        run: pnpm run test-build
+        env:
+          _VITE_TEST_JS_PLUGIN: 1
+
   lint:
     timeout-minutes: 10
     runs-on: ubuntu-latest

.github/workflows/preview-release.yml

@@ -44,8 +44,12 @@ jobs:
         env:
           PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: "1"
 
-      - name: Build
+      - name: Build Vite core
         working-directory: ./packages/vite
         run: pnpm build
 
-      - run: pnpm dlx pkg-pr-new@0.0 publish --compact --pnpm ./packages/vite
+      - name: Build plugin-legacy
+        working-directory: ./packages/plugin-legacy
+        run: pnpm build
+
+      - run: pnpm dlx pkg-pr-new@0.0 publish --pnpm './packages/vite' './packages/plugin-legacy'

docs/.vitepress/config.ts

@@ -301,10 +301,6 @@ export default defineConfig({
               text: 'Performance',
               link: '/guide/performance',
             },
-            {
-              text: 'Rolldown',
-              link: '/guide/rolldown',
-            },
             {
               text: `Migration from v${viteMajorVersion - 1}`,
               link: '/guide/migration',

docs/config/build-options.md

@@ -12,9 +12,9 @@ Browser compatibility target for the final bundle. The default value is a Vite s
 
 Another special value is `'esnext'` - which assumes native dynamic imports support and will only perform minimal transpiling.
 
-The transform is performed with esbuild and the value should be a valid [esbuild target option](https://esbuild.github.io/api/#target). Custom targets can either be an ES version (e.g. `es2015`), a browser with version (e.g. `chrome58`), or an array of multiple target strings.
+The transform is performed with Oxc Transformer and the value should be a valid [Oxc Transformer target option](https://oxc.rs/docs/guide/usage/transformer/lowering#target). Custom targets can either be an ES version (e.g. `es2015`), a browser with version (e.g. `chrome58`), or an array of multiple target strings.
 
-Note the build will fail if the code contains features that cannot be safely transpiled by esbuild. See [esbuild docs](https://esbuild.github.io/content-types/#javascript) for more details.
+Note the build will output a warning if the code contains features that cannot be safely transpiled by Oxc. See [Oxc docs](https://oxc.rs/docs/guide/usage/transformer/lowering#warnings) for more details.
 
 ## build.modulePreload
 
@@ -129,10 +129,16 @@ In this case, you need to set `build.cssTarget` to `chrome61` to prevent vite fr
 
 ## build.cssMinify
 
-- **Type:** `boolean | 'esbuild' | 'lightningcss'`
-- **Default:** the same as [`build.minify`](#build-minify) for client, `'esbuild'` for SSR
+- **Type:** `boolean | 'lightningcss' | 'esbuild'`
+- **Default:** the same as [`build.minify`](#build-minify) for client, `'lightningcss'` for SSR
 
-This option allows users to override CSS minification specifically instead of defaulting to `build.minify`, so you can configure minification for JS and CSS separately. Vite uses `esbuild` by default to minify CSS. Set the option to `'lightningcss'` to use [Lightning CSS](https://lightningcss.dev/minification.html) instead. If selected, it can be configured using [`css.lightningcss`](./shared-options.md#css-lightningcss).
+This option allows users to override CSS minification specifically instead of defaulting to `build.minify`, so you can configure minification for JS and CSS separately. Vite uses [Lightning CSS](https://lightningcss.dev/minification.html) by default to minify CSS. It can be configured using [`css.lightningcss`](./shared-options.md#css-lightningcss). Set the option to `'esbuild'` to use esbuild instead.
+
+esbuild must be installed when it is set to `'esbuild'`.
+
+```sh
+npm add -D esbuild
+```
 
 ## build.sourcemap
 
@@ -141,17 +147,20 @@ This option allows users to override CSS minification specifically instead of de
 
 Generate production source maps. If `true`, a separate sourcemap file will be created. If `'inline'`, the sourcemap will be appended to the resulting output file as a data URI. `'hidden'` works like `true` except that the corresponding sourcemap comments in the bundled files are suppressed.
 
-## build.rollupOptions
+## build.rolldownOptions
 
-- **Type:** [`RollupOptions`](https://rollupjs.org/configuration-options/)
+- **Type:** [`RolldownOptions`](https://rollupjs.org/configuration-options/)
 
-Directly customize the underlying Rollup bundle. This is the same as options that can be exported from a Rollup config file and will be merged with Vite's internal Rollup options. See [Rollup options docs](https://rollupjs.org/configuration-options/) for more details.
+<!-- TODO: update the link above and below to Rolldown's documentation -->
 
-## build.commonjsOptions
+Directly customize the underlying Rolldown bundle. This is the same as options that can be exported from a Rolldown config file and will be merged with Vite's internal Rolldown options. See [Rolldown options docs](https://rollupjs.org/configuration-options/) for more details.
 
-- **Type:** [`RollupCommonJSOptions`](https://github.com/rollup/plugins/tree/master/packages/commonjs#options)
+## build.rollupOptions
+
+- **Type:** `RolldownOptions`
+- **Deprecated**
 
-Options to pass on to [@rollup/plugin-commonjs](https://github.com/rollup/plugins/tree/master/packages/commonjs).
+This option is an alias of `build.rolldownOptions` option. Use `build.rolldownOptions` option instead.
 
 ## build.dynamicImportVarsOptions
 
@@ -160,6 +169,8 @@ Options to pass on to [@rollup/plugin-commonjs](https://github.com/rollup/plugin
 
 Options to pass on to [@rollup/plugin-dynamic-import-vars](https://github.com/rollup/plugins/tree/master/packages/dynamic-import-vars).
 
+<!-- TODO: we need to have a more detailed explanation here as we no longer use @rollup/plugin-dynamic-import-vars. we should say it's compatible with it though -->
+
 ## build.lib
 
 - **Type:** `{ entry: string | string[] | { [entryAlias: string]: string }, name?: string, formats?: ('es' | 'cjs' | 'umd' | 'iife')[], fileName?: string | ((format: ModuleFormat, entryName: string) => string), cssFileName?: string }`
@@ -256,16 +267,19 @@ During the SSR build, static assets aren't emitted as it is assumed they would b
 
 ## build.minify
 
-- **Type:** `boolean | 'terser' | 'esbuild'`
-- **Default:** `'esbuild'` for client build, `false` for SSR build
+- **Type:** `boolean | 'oxc' | 'terser' | 'esbuild'`
+- **Default:** `'oxc'` for client build, `false` for SSR build
 
-Set to `false` to disable minification, or specify the minifier to use. The default is [esbuild](https://github.com/evanw/esbuild) which is 20 ~ 40x faster than terser and only 1 ~ 2% worse compression. [Benchmarks](https://github.com/privatenumber/minification-benchmarks)
+Set to `false` to disable minification, or specify the minifier to use. The default is [Oxc Minifier](https://oxc.rs/docs/guide/usage/minifier) which is 30 ~ 90x faster than terser and only 0.5 ~ 2% worse compression. [Benchmarks](https://github.com/privatenumber/minification-benchmarks)
+
+`build.minify: 'esbuild'` is deprecated and will be removed in the future.
 
 Note the `build.minify` option does not minify whitespaces when using the `'es'` format in lib mode, as it removes pure annotations and breaks tree-shaking.
 
-Terser must be installed when it is set to `'terser'`.
+esbuild or Terser must be installed when it is set to `'esbuild'` or `'terser'` respectively.
 
 ```sh
+npm add -D esbuild
 npm add -D terser
 ```
 
@@ -314,6 +328,8 @@ Limit for chunk size warnings (in kB). It is compared against the uncompressed c
 
 ## build.watch
 
+<!-- TODO: update the link below to Rolldown's documentation -->
+
 - **Type:** [`WatcherOptions`](https://rollupjs.org/configuration-options/#watch)`| null`
 - **Default:** `null`
 

docs/config/dep-optimization-options.md

@@ -51,6 +51,23 @@ export default defineConfig({
 })
 ```
 
+## optimizeDeps.rolldownOptions <NonInheritBadge />
+
+- **Type:** [`Omit`](https://www.typescriptlang.org/docs/handbook/utility-types.html#omittype-keys)`<``RolldownOptions`, `'input' | 'logLevel' | 'output'> & {
+  output?: [`Omit`](https://www.typescriptlang.org/docs/handbook/utility-types.html#omittype-keys)`<`
+    `RolldownOutputOptions`,
+    `'format' | 'sourcemap' | 'dir' | 'banner'>`
+`}`
+
+<!-- TODO: add link to RolldownOptions -->
+<!-- TODO: add link to RolldownOutputOptions -->
+
+Options to pass to Rolldown during the dep scanning and optimization.
+
+Certain options are omitted since changing them would not be compatible with Vite's dep optimization.
+
+- `plugins` are merged with Vite's dep plugin
+
 ## optimizeDeps.esbuildOptions <NonInheritBadge />
 
 - **Type:** [`Omit`](https://www.typescriptlang.org/docs/handbook/utility-types.html#omittype-keys)`<`[`EsbuildBuildOptions`](https://esbuild.github.io/api/#general-options)`,
@@ -64,13 +81,9 @@ export default defineConfig({
 | 'outbase'
 | 'outExtension'
 | 'metafile'>`
+- **Deprecated**
 
-Options to pass to esbuild during the dep scanning and optimization.
-
-Certain options are omitted since changing them would not be compatible with Vite's dep optimization.
-
-- `external` is also omitted, use Vite's `optimizeDeps.exclude` option
-- `plugins` are merged with Vite's dep plugin
+This option is converted to `optimizeDeps.rolldownOptions` internally. Use `optimizeDeps.rolldownOptions` instead.
 
 ## optimizeDeps.force <NonInheritBadge />
 

docs/config/index.md

@@ -23,7 +23,7 @@ vite --config my-config.js
 ```
 
 ::: tip CONFIG LOADING
-By default, Vite uses `esbuild` to bundle the config into a temporary file and load it. This may cause issues when importing TypeScript files in a monorepo. If you encounter any issues with this approach, you can specify `--configLoader runner` to use the [module runner](/guide/api-environment-runtimes.html#modulerunner) instead, which will not create a temporary config and will transform any files on the fly. Note that module runner doesn't support CJS in config files, but external CJS packages should work as usual.
+By default, Vite uses [Rolldown](https://rolldown.rs/) to bundle the config into a temporary file and load it. This may cause issues when importing TypeScript files in a monorepo. If you encounter any issues with this approach, you can specify `--configLoader runner` to use the [module runner](/guide/api-environment-runtimes.html#modulerunner) instead, which will not create a temporary config and will transform any files on the fly. Note that module runner doesn't support CJS in config files, but external CJS packages should work as usual.
 
 Alternatively, if you're using an environment that supports TypeScript (e.g. `node --experimental-strip-types`), or if you're only writing plain JavaScript, you can specify `--configLoader native` to use the environment's native runtime to load the config file. Note that updates to modules imported by the config file are not detected and hence would not auto-restart the Vite server.
 :::

docs/config/shared-options.md

@@ -40,7 +40,7 @@ See [Env Variables and Modes](/guide/env-and-mode) for more details.
 
 Define global constant replacements. Entries will be defined as globals during dev and statically replaced during build.
 
-Vite uses [esbuild defines](https://esbuild.github.io/api/#define) to perform replacements, so value expressions must be a string that contains a JSON-serializable value (null, boolean, number, string, array, or object) or a single identifier. For non-string values, Vite will automatically convert it to a string with `JSON.stringify`.
+Vite uses [Oxc's define feature](https://oxc.rs/docs/guide/usage/transformer/global-variable-replacement#define) to perform replacements, so value expressions must be a string that contains a JSON-serializable value (null, boolean, number, string, array, or object) or a single identifier. For non-string values, Vite will automatically convert it to a string with `JSON.stringify`.
 
 **Example:**
 
@@ -96,6 +96,8 @@ Directory to save cache files. Files in this directory are pre-bundled deps or s
 
 Will be passed to `@rollup/plugin-alias` as its [entries option](https://github.com/rollup/plugins/tree/master/packages/alias#entries). Can either be an object, or an array of `{ find, replacement, customResolver }` pairs.
 
+<!-- TODO: we need to have a more detailed explanation here as we no longer use @rollup/plugin-alias. we should say it's compatible with it though -->
+
 When aliasing to file system paths, always use absolute paths. Relative alias values will be used as-is and will not be resolved into file system paths.
 
 More advanced custom resolution can be achieved through [plugins](/guide/api-plugin).
@@ -353,36 +355,44 @@ If set to `true`, imported JSON will be transformed into `export default JSON.pa
 
 If set to `'auto'`, the data will be stringified only if [the data is bigger than 10kB](https://v8.dev/blog/cost-of-javascript-2019#json:~:text=A%20good%20rule%20of%20thumb%20is%20to%20apply%20this%20technique%20for%20objects%20of%2010%20kB%20or%20larger).
 
-## esbuild
+## oxc
 
-- **Type:** `ESBuildOptions | false`
+- **Type:** `OxcOptions | false`
 
-`ESBuildOptions` extends [esbuild's own transform options](https://esbuild.github.io/api/#transform). The most common use case is customizing JSX:
+`OxcOptions` extends [Oxc Transformer's options](https://oxc.rs/docs/guide/usage/transformer). The most common use case is customizing JSX:
 
 ```js
 export default defineConfig({
-  esbuild: {
-    jsxFactory: 'h',
-    jsxFragment: 'Fragment',
+  oxc: {
+    jsx: {
+      runtime: 'classic',
+      pragma: 'h',
+      pragmaFrag: 'Fragment',
+    },
   },
 })
 ```
 
-By default, esbuild is applied to `ts`, `jsx` and `tsx` files. You can customize this with `esbuild.include` and `esbuild.exclude`, which can be a regex, a [picomatch](https://github.com/micromatch/picomatch#globbing-features) pattern, or an array of either.
+By default, transformation by Oxc is applied to `ts`, `jsx` and `tsx` files. You can customize this with `oxc.include` and `oxc.exclude`, which can be a regex, a [picomatch](https://github.com/micromatch/picomatch#globbing-features) pattern, or an array of either.
 
-In addition, you can also use `esbuild.jsxInject` to automatically inject JSX helper imports for every file transformed by esbuild:
+In addition, you can also use `oxc.jsxInject` to automatically inject JSX helper imports for every file transformed by Oxc:
 
 ```js
 export default defineConfig({
-  esbuild: {
+  oxc: {
     jsxInject: `import React from 'react'`,
   },
 })
 ```
 
-When [`build.minify`](./build-options.md#build-minify) is `true`, all minify optimizations are applied by default. To disable [certain aspects](https://esbuild.github.io/api/#minify) of it, set any of `esbuild.minifyIdentifiers`, `esbuild.minifySyntax`, or `esbuild.minifyWhitespace` options to `false`. Note the `esbuild.minify` option can't be used to override `build.minify`.
+Set to `false` to disable transformation by Oxc.
+
+## esbuild
+
+- **Type:** `ESBuildOptions | false`
+- **Deprecated**
 
-Set to `false` to disable esbuild transforms.
+This option is converted to `oxc` option internally. Use `oxc` option instead.
 
 ## assetsInclude
 

docs/config/worker-options.md

@@ -18,6 +18,15 @@ The function should return new plugin instances as they are used in parallel rol
 
 ## worker.rollupOptions
 
-- **Type:** [`RollupOptions`](https://rollupjs.org/configuration-options/)
+<!-- TODO: update the link below to Rolldown's documentation -->
+
+- **Type:** [`RolldownOptions`](https://rollupjs.org/configuration-options/)
 
 Rollup options to build worker bundle.
+
+## worker.rollupOptions
+
+- **Type:** `RolldownOptions`
+- **Deprecated**
+
+This option is an alias of `worker.rolldownOptions` option. Use `build.rolldownOptions` option instead.

docs/guide/api-javascript.md

@@ -389,6 +389,21 @@ function normalizePath(id: string): string
 
 Normalizes a path to interoperate between Vite plugins.
 
+## `transformWithOxc`
+
+**Type Signature:**
+
+```ts
+async function transformWithOxc(
+  code: string,
+  filename: string,
+  options?: OxcTransformOptions,
+  inMap?: object,
+): Promise<Omit<OxcTransformResult, 'errors'> & { warnings: string[] }>
+```
+
+Transform JavaScript or TypeScript with [Oxc Transformer](https://oxc.rs/docs/guide/usage/transformer). Useful for plugins that prefer matching Vite's internal Oxc Transformer transform.
+
 ## `transformWithEsbuild`
 
 **Type Signature:**
@@ -402,6 +417,8 @@ async function transformWithEsbuild(
 ): Promise<ESBuildTransformResult>
 ```
 
+**Deprecated:** Use `transformWithOxc` instead.
+
 Transform JavaScript or TypeScript with esbuild. Useful for plugins that prefer matching Vite's internal esbuild transform.
 
 ## `loadConfigFromFile`