[npm]: https://img.shields.io/npm/v/@rollup/plugin-node-resolve [npm-url]: https://www.npmjs.com/package/@rollup/plugin-node-resolve [size]: https://packagephobia.now.sh/badge?p=@rollup/plugin-node-resolve [size-url]: https://packagephobia.now.sh/result?p=@rollup/plugin-node-resolve [![npm][npm]][npm-url] [![size][size]][size-url] [![libera manifesto](https://img.shields.io/badge/libera-manifesto-lightgrey.svg)](https://liberamanifesto.com) # @rollup/plugin-node-resolve 🍣 A Rollup plugin which locates modules using the [Node resolution algorithm](https://nodejs.org/api/modules.html#modules_all_together), for using third party modules in `node_modules` ## Requirements This plugin requires an [LTS](https://github.com/nodejs/Release) Node version (v14.0.0+) and Rollup v2.78.0+. ## Install Using npm: ```console npm install @rollup/plugin-node-resolve --save-dev ``` ## Usage Create a `rollup.config.js` [configuration file](https://www.rollupjs.org/guide/en/#configuration-files) and import the plugin: ```js import { nodeResolve } from '@rollup/plugin-node-resolve'; export default { input: 'src/index.js', output: { dir: 'output', format: 'cjs' }, plugins: [nodeResolve()] }; ``` Then call `rollup` either via the [CLI](https://www.rollupjs.org/guide/en/#command-line-reference) or the [API](https://www.rollupjs.org/guide/en/#javascript-api). ## Package entrypoints This plugin supports the package entrypoints feature from node js, specified in the `exports` or `imports` field of a package. Check the [official documentation](https://nodejs.org/api/packages.html#packages_package_entry_points) for more information on how this works. This is the default behavior. In the abscence of these fields, the fields in `mainFields` will be the ones to be used. ## Options ### `exportConditions` Type: `Array[...String]`
Default: `[]` Additional conditions of the package.json exports field to match when resolving modules. By default, this plugin looks for the `['default', 'module', 'import', 'development|production']` conditions when resolving imports. If neither the `development` or `production` conditions are provided it will default to `production` - or `development` if `NODE_ENV` is set to a value other than `production`. When using `@rollup/plugin-commonjs` v16 or higher, this plugin will use the `['default', 'module', 'require']` conditions when resolving require statements. Setting this option will add extra conditions on top of the default conditions. See https://nodejs.org/api/packages.html#packages_conditional_exports for more information. In order to get the [resolution behavior of Node.js](https://nodejs.org/api/packages.html#packages_conditional_exports), set this to `['node']`. ### `browser` Type: `Boolean`
Default: `false` If `true`, instructs the plugin to use the browser module resolutions in `package.json` and adds `'browser'` to `exportConditions` if it is not present so browser conditionals in `exports` are applied. If `false`, any browser properties in package files will be ignored. Alternatively, a value of `'browser'` can be added to both the `mainFields` and `exportConditions` options, however this option takes precedence over `mainFields`. > This option does not work when a package is using [package entrypoints](https://nodejs.org/api/packages.html#packages_package_entry_points) ### `moduleDirectories` Type: `Array[...String]`
Default: `['node_modules']` A list of directory names in which to recursively look for modules. ### `modulePaths` Type: `Array[...String]`
Default: `[]` A list of absolute paths to additional locations to search for modules. [This is analogous to setting the `NODE_PATH` environment variable for node](https://nodejs.org/api/modules.html#loading-from-the-global-folders). ### `dedupe` Type: `Array[...String]`
Default: `[]` An `Array` of modules names, which instructs the plugin to force resolving for the specified modules to the root `node_modules`. Helps to prevent bundling the same package multiple times if package is imported from dependencies. ```js dedupe: ['my-package', '@namespace/my-package']; ``` This will deduplicate bare imports such as: ```js import 'my-package'; import '@namespace/my-package'; ``` And it will deduplicate deep imports such as: ```js import 'my-package/foo.js'; import '@namespace/my-package/bar.js'; ``` ### `extensions` Type: `Array[...String]`
Default: `['.mjs', '.js', '.json', '.node']` Specifies the extensions of files that the plugin will operate on. ### `jail` Type: `String`
Default: `'/'` Locks the module search within specified path (e.g. chroot). Modules defined outside this path will be ignored by this plugin. ### `mainFields` Type: `Array[...String]`
Default: `['module', 'main']`
Valid values: `['browser', 'jsnext:main', 'module', 'main']` Specifies the properties to scan within a `package.json`, used to determine the bundle entry point. The order of property names is significant, as the first-found property is used as the resolved entry point. If the array contains `'browser'`, key/values specified in the `package.json` `browser` property will be used. ### `preferBuiltins` Type: `Boolean | (module: string) => boolean`
Default: `true` (with warnings if a builtin module is used over a local version. Set to `true` to disable warning.) If `true`, the plugin will prefer built-in modules (e.g. `fs`, `path`). If `false`, the plugin will look for locally installed modules of the same name. Alternatively, you may pass in a function that returns a boolean to confirm whether the plugin should prefer built-in modules. e.g. ```js preferBuiltins: (module) => module !== 'punycode'; ``` will not treat `punycode` as a built-in module ### `modulesOnly` Type: `Boolean`
Default: `false` If `true`, inspect resolved files to assert that they are ES2015 modules. ### `resolveOnly` Type: `Array[...String|RegExp] | (module: string) => boolean`
Default: `null` An `Array` which instructs the plugin to limit module resolution to those whose names match patterns in the array. _Note: Modules not matching any patterns will be marked as external._ Alternatively, you may pass in a function that returns a boolean to confirm whether the module should be included or not. Examples: - `resolveOnly: ['batman', /^@batcave\/.*$/]` - `resolveOnly: module => !module.includes('joker')` ### `rootDir` Type: `String`
Default: `process.cwd()` Specifies the root directory from which to resolve modules. Typically used when resolving entry-point imports, and when resolving deduplicated modules. Useful when executing rollup in a package of a mono-repository. ``` // Set the root directory to be the parent folder rootDir: path.join(process.cwd(), '..') ``` ### `ignoreSideEffectsForRoot` Type: `Boolean`
Default: `false` If you use the `sideEffects` property in the package.json, by default this is respected for files in the root package. Set to `true` to ignore the `sideEffects` configuration for the root package. ### `allowExportsFolderMapping` Older Node versions supported exports mappings of folders like ```json { "exports": { "./foo/": "./dist/foo/" } } ``` This was deprecated with Node 14 and removed in Node 17, instead it is recommended to use exports patterns like ```json { "exports": { "./foo/*": "./dist/foo/*" } } ``` But for backwards compatibility this behavior is still supported by enabling the `allowExportsFolderMapping` (defaults to `true`). The default value might change in a futur major release. ## Preserving symlinks This plugin honours the rollup [`preserveSymlinks`](https://rollupjs.org/guide/en/#preservesymlinks) option. ## Using with @rollup/plugin-commonjs Since most packages in your node_modules folder are probably legacy CommonJS rather than JavaScript modules, you may need to use [@rollup/plugin-commonjs](https://github.com/rollup/plugins/tree/master/packages/commonjs): ```js // rollup.config.js import { nodeResolve } from '@rollup/plugin-node-resolve'; import commonjs from '@rollup/plugin-commonjs'; export default { input: 'main.js', output: { file: 'bundle.js', format: 'iife', name: 'MyModule' }, plugins: [nodeResolve(), commonjs()] }; ``` ## Resolving Built-Ins (like `fs`) By default this plugin will prefer built-ins over local modules, marking them as external. See [`preferBuiltins`](#preferbuiltins). To provide stubbed versions of Node built-ins, use a plugin like [rollup-plugin-node-polyfills](https://github.com/ionic-team/rollup-plugin-node-polyfills) and set `preferBuiltins` to `false`. e.g. ```js import { nodeResolve } from '@rollup/plugin-node-resolve'; import nodePolyfills from 'rollup-plugin-node-polyfills'; export default ({ input: ..., plugins: [ nodePolyfills(), nodeResolve({ preferBuiltins: false }) ], external: builtins, output: ... }) ``` ## Resolving Require Statements According to [NodeJS module resolution](https://nodejs.org/api/packages.html#packages_package_entry_points) `require` statements should resolve using the `require` condition in the package exports field, while es modules should use the `import` condition. The node resolve plugin uses `import` by default, you can opt into using the `require` semantics by passing an extra option to the resolve function: ```js this.resolve(importee, importer, { skipSelf: true, custom: { 'node-resolve': { isRequire: true } } }); ``` ## Resolve Options After this plugin resolved an import id to its target file in `node_modules`, it will invoke `this.resolve` again with the resolved id. It will pass the following information in the resolve options: ```js this.resolve(resolved.id, importer, { custom: { 'node-resolve': { resolved, // the object with information from node.js resolve importee // the original import id } } }); ``` Your plugin can use the `importee` information to map an original import to its resolved file in `node_modules`, in a plugin hook such as `resolveId`. The `resolved` object contains the resolved id, which is passed as the first parameter. It also has a property `moduleSideEffects`, which may contain the value from the npm `package.json` field `sideEffects` or `null`. ## Meta [CONTRIBUTING](/.github/CONTRIBUTING.md) [LICENSE (MIT)](/LICENSE)