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Config Options ​

🚧 Under Construction

We are working on generating a more detailed reference. For now, please refer to Rollup's Config Options Reference and documentation on additional notable features.

InputOptions ​

input ​

plugins ​

external ​

resolve ​

resolve.alias ​

WARNING

resolve.alias will not call resolveId hooks of other plugin. If you want to call resolveId hooks of other plugin, use aliasPlugin from rolldown/experimental instead. You could find more discussion in this issue

resolve.aliasFields ​

resolve.conditionNames ​

resolve.extensionAlias ​

Map of extensions to alternative extensions.

With writing import './foo.js' in a file, you want to resolve it to foo.ts instead of foo.js. You can achieve this by setting: extensionAlias: { '.js': ['.ts', '.js'] }.

resolve.exportsFields ​

resolve.extensions ​

resolve.mainFields ​

resolve.mainFiles ​

resolve.modules ​

resolve.tsconfigFilename ​

cwd ​

platform ​

Expected platform where the code run.

shimMissingExports ​

treeshake ​

logLevel ​

onLog ​

onwarn ​

moduleTypes ​

experimental ​

experimental.strictExecutionOrder ​

experimental.disableLiveBindings ​

experimental.viteMode ​

experimental.resolveNewUrlToAsset ​

experimental.hmr ​

experimental.chunkModulesOrder ​

Control which order should use when rendering modules in chunk

  • Type: `'exec-order' | 'module-id'

  • Default: 'exec-order'

  • exec-order: Almost equivalent to the topological order of the module graph, but specially handling when module graph has cycle.

  • module-id: This is more friendly for gzip compression, especially for some javascript static asset lib (e.g. icon library)

NOTE

Try to sort the modules by their module id if possible(Since rolldown scope hoist all modules in the chunk, we only try to sort those modules by module id if we could ensure runtime behavior is correct after sorting).

experimental.attachDebugInfo ​

Attach debug information to the output bundle.

  • Type: 'none' | 'simple' | 'full'

  • Default: 'simple'

  • none: No debug information is attached.

  • simple: Attach comments indicating which files the bundled code comes from. These comments could be removed by the minifier.

  • full: Attach detailed debug information to the output bundle. These comments are using legal comment syntax, so they won't be removed by the minifier.

WARNING

You shouldn't use full in the production build.

experimental.chunkImportMap ​

Enables automatic generation of a chunk import map asset during build.

This map only includes chunks with hashed filenames, where keys are derived from the facade module name or primary chunk name. It produces stable and unique hash-based filenames, effectively preventing cascading cache invalidation caused by content hashes and maximizing browser cache reuse.

The output defaults to importmap.json unless overridden via fileName. A base URL prefix (default "/") can be applied to all paths. The resulting JSON is a valid import map and can be directly injected into HTML via <script type="importmap">.

Example configuration snippet:

js
{
  experimental: {
    chunkImportMap: {
      baseUrl: '/',
      fileName: 'importmap.json'
    }
  },
  plugins: [
    {
      name: 'inject-import-map',
      generateBundle(_, bundle) {
        const chunkImportMap = bundle['importmap.json'];
        if (chunkImportMap?.type === 'asset') {
          const htmlPath = path.resolve('index.html');
          let html = fs.readFileSync(htmlPath, 'utf-8');

          html = html.replace(
            /<script\s+type="importmap"[^>]*>[\s\S]*?</script>/i,
            `<script type="importmap">${chunkImportMap.source}</script>`
          );

          fs.writeFileSync(htmlPath, html);
          delete bundle['importmap.json'];
        }
      }
    }
  ]
}

NOTE

If you want to learn more, you can check out the example here: examples/chunk-import-map

experimental.onDemandWrapping ​

experimental.incrementalBuild ​

Required to be used with watch mode.

experimental.transformHiresSourcemap ​

define ​

Replace global variables or property accessors with the provided values.

Examples ​

  • Replace the global variable IS_PROD with true
js
export default defineConfig({ define: { IS_PROD: 'true' // or JSON.stringify(true) } })

Result:

js
// Input
if (IS_PROD) {
  console.log('Production mode')
}

// After bundling
if (true) {
  console.log('Production mode')
}
  • Replace the property accessor process.env.NODE_ENV with 'production'
js
export default defineConfig({ define: { 'process.env.NODE_ENV': "'production'" } })

Result:

js
// Input
if (process.env.NODE_ENV === 'production') {
 console.log('Production mode')
}

// After bundling
if ('production' === 'production') {
console.log('Production mode')
}

inject ​

Inject import statements on demand.

Supported patterns ​
js
{
  // import { Promise } from 'es6-promise'
  Promise: ['es6-promise', 'Promise'],

  // import { Promise as P } from 'es6-promise'
  P: ['es6-promise', 'Promise'],

  // import $ from 'jquery'
  $: 'jquery',

  // import * as fs from 'node:fs'
  fs: ['node:fs', '*'],

  // Inject shims for property access pattern
  'Object.assign': path.resolve( 'src/helpers/object-assign.js' ),
}

profilerNames ​

jsx ​

  • false disables the JSX parser, resulting in a syntax error if JSX syntax is used.
  • "preserve" disables the JSX transformer, preserving the original JSX syntax in the output.
  • "react" enables the classic JSX transformer.
  • "react-jsx" enables the automatic JSX transformer.

transform ​

Configure how the code is transformed. This process happens after the transform hook.

To transpile legacy decorators, you could use

js
export default defineConfig({
  transform: {
    decorator: {
      legacy: true,
    },
  },
})

For latest decorators proposal, rolldown is able to bundle them but doesn't support transpiling them yet.

watch ​

dropLabels ​

keepNames ​

checks ​

makeAbsoluteExternalsRelative ​

debug ​

debug.sessionId ​

preserveEntrySignatures ​

optimization ​

OutputOptions ​

dir ​

file ​

exports ​

hashCharacters ​

format ​

Expected format of generated code.

sourcemap ​

sourcemapBaseUrl ​

sourcemapDebugIds ​

sourcemapIgnoreList ​

sourcemapPathTransform ​

intro ​

outro ​

extend ​

esModule ​

assetFileNames ​

entryFileNames ​

chunkFileNames ​

cssEntryFileNames ​

cssChunkFileNames ​

sanitizeFileName ​

minify ​

name ​

globals ​

externalLiveBindings ​

inlineDynamicImports ​

manualChunks ​

  • Type: ((moduleId: string, meta: { getModuleInfo: (moduleId: string) => ModuleInfo | null }) => string | NullValue)
  • Object form is not supported.

WARNING

  • This option is deprecated. Please use advancedChunks instead.
  • If manualChunks and advancedChunks are both specified, manualChunks option will be ignored.

You could use this option for migration purpose. Under the hood,

js
{
  manualChunks: (moduleId, meta) => {
    if (moduleId.includes('node_modules')) {
      return 'vendor';
    }
    return null;
  }
}

will be transformed to

js
{
  advancedChunks: {
    groups: [
      {
        name(moduleId) {
          if (moduleId.includes('node_modules')) {
            return 'vendor';
          }
          return null;
        },
      },
    ],
  }
}

advancedChunks ​

Allows you to do manual chunking. For deeper understanding, please refer to the in-depth documentation.

advancedChunks.minSize ​

  • Type: number

Global fallback of {group}.minSize, if it's not specified in the group.

advancedChunks.maxSize ​

  • Type: number

Global fallback of {group}.maxSize, if it's not specified in the group.

advancedChunks.maxModuleSize ​

  • Type: number

Global fallback of {group}.maxModuleSize, if it's not specified in the group.

advancedChunks.minModuleSize ​

  • Type: number

Global fallback of {group}.minModuleSize, if it's not specified in the group.

advancedChunks.minShareCount ​

  • Type: number

Global fallback of {group}.minShareCount, if it's not specified in the group.

advancedChunks.groups ​

Groups to be used for advanced chunking.

advancedChunks.groups.name ​
  • Type: string | ((moduleId: string, ctx: { getModuleInfo: (moduleId: string) => ModuleInfo | null }) => string | NullValue)

Name of the group. It will be also used as the name of the chunk and replaced the [name] placeholder in the chunkFileNames option.

For example,

js
import { defineConfig } from 'rolldown';

export default defineConfig({
  advancedChunks: {
    groups: [
      {
        name: 'libs',
        test: /node_modules/,
      },
    ],
  },
});

will create a chunk named libs-[hash].js in the end.

It's ok to have the same name for different groups. Rolldown will deduplicate the chunk names if necessary.

Dynamic name() ​

If name is a function, it will be called with the module id as the argument. The function should return a string or null. If it returns null, the module will be ignored by this group.

Notice, each returned new name will be treated as a separate group.

For example,

js
import { defineConfig } from 'rolldown';

export default defineConfig({
  advancedChunks: {
    groups: [
      {
        name: (moduleId) => moduleId.includes('node_modules') ? 'libs' : 'app',
        minSize: 100 * 1024,
      },
    ],
  },
});

WARNING

Constraints like minSize, maxSize, etc. are applied separately for different names returned by the function.

advancedChunks.groups.test ​
  • Type: string | RegExp | ((id: string) => boolean | undefined | void);

Controls which modules are captured in this group.

  • If test is a string, the module whose id contains the string will be captured.
  • If test is a regular expression, the module whose id matches the regular expression will be captured.
  • If test is a function, modules for which test(id) returns true will be captured.
  • If test is empty, any module will be considered as matched.

WARNING

When using regular expression, it's recommended to use [\\/] to match the path separator instead of / to avoid potential issues on Windows.

  • ✅ Recommended: /node_modules[\\/]react/
  • ❌ Not recommended: /node_modules/react/
advancedChunks.groups.priority ​
  • Type: number
  • Default: 0

Priority of the group. Group with higher priority will be chosen first to match modules and create chunks. When converting the group to a chunk, modules of that group will be removed from other groups.

If two groups have the same priority, the group whose index is smaller will be chosen.

For example,

js
import { defineConfig } from 'rolldown';

export default defineConfig({
 advancedChunks: {
  groups: [
     {
       name: 'react',
       test: /node_modules[\\/]react/,
       priority: 1,
     },
     {
       name: 'other-libs',
       test: /node_modules/,
       priority: 2,
     },
  ],
});

This is a clearly incorrect example. Though react group is defined before other-libs, it has a lower priority, so the modules in react group will be captured in other-libs group.

advancedChunks.groups.minSize ​
  • Type: number
  • Default: 0

Minimum size in bytes of the desired chunk. If the accumulated size of the captured modules by this group is smaller than this value, it will be ignored. Modules in this group will fall back to the automatic chunking if they are not captured by any other group.

advancedChunks.groups.minShareCount ​
  • Type: number
  • Default: 1

Controls if a module should be captured based on how many entry chunks reference it.

advancedChunks.groups.maxSize ​
  • Type: number
  • Default: Infinity

If the accumulated size in bytes of the captured modules by this group is larger than this value, this group will be split into multiple groups that each has size close to this value.

advancedChunks.groups.maxModuleSize ​
  • Type: number
  • Default: Infinity

Controls a module could only be captured if its size in bytes is smaller or equal than this value.

advancedChunks.groups.minModuleSize ​
  • Type: number
  • Default: 0

Controls a module could only be captured if its size in bytes is larger or equal than this value.

legalComments ​

Control comments in the output.

  • none: no comments
  • inline: preserve comments that contain @license, @preserve or starts with //! /*!

plugins ​

polyfillRequire ​

hoistTransitiveImports ​

preserveModules ​

virtualDirname ​

preserveModulesRoot ​

topLevelVar ​

minifyInternalExports ​

  • Type: boolean
  • Default: false

Whether to minify internal exports.

Released under the MIT License.

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