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exports-loader

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<div align="center"> <a href="https://github.com/webpack/webpack"> <img width="200" height="200" src="https://webpack.js.org/assets/icon-square-big.svg"> </a> </div> [![npm][npm]][npm-url] [![node][node]][node-url] [![tests][tests]][tests-url] [![coverage][cover]][cover-url] [![discussion][discussion]][discussion-url] [![size][size]][size-url] # exports-loader Allow to setup exports `module.exports`/`export` for source files. Useful when a source file does not contain exports or something does not export. For further hints on compatibility issues, check out [Shimming](https://webpack.js.org/guides/shimming/) of the official docs. > **Warning** > > By default loader generate ES module named syntax. > **Warning** > > Be careful, existing exports (`export`/`module.exports`/`exports`) in the original code and exporting new values can cause a failure. ## Getting Started To begin, you'll need to install `exports-loader`: ```console npm install exports-loader --save-dev ``` or ```console yarn add -D exports-loader ``` or ```console pnpm add -D exports-loader ``` ### Inline The `|` or `%20` (space) allow to separate the `syntax`, `name` and `alias` of export. The documentation and syntax examples can be read [here](#syntax). > **Warning** > > `%20` is space in a query string, because you can't use spaces in URLs Then add the loader to the desired `import` statement or `require` calls. For example: ```js import { myFunction } from "exports-loader?exports=myFunction!./file.js"; // Adds the following code to the file's source: // // ... // Code // ... // // export { myFunction } myFunction("Hello world"); ``` ```js import { myVariable, myFunction, } from "exports-loader?exports=myVariable,myFunction!./file.js"; // Adds the following code to the file's source: // // ... // Code // ... // // export { myVariable, myFunction }; const newVariable = myVariable + "!!!"; console.log(newVariable); myFunction("Hello world"); ``` ```js const { myFunction, } = require("exports-loader?type=commonjs&exports=myFunction!./file.js"); // Adds the following code to the file's source: // // ... // Code // ... // // module.exports = { myFunction } myFunction("Hello world"); ``` ```js // Alternative syntax: // import myFunction from 'exports-loader?exports=default%20myFunction!./file.js'; import myFunction from "exports-loader?exports=default|myFunction!./file.js"; // `%20` is space in a query string, equivalently `default myFunction` // Adds the following code to the file's source: // // ... // Code // ... // // exports default myFunction; myFunction("Hello world"); ``` ```js const myFunction = require("exports-loader?type=commonjs&exports=single|myFunction!./file.js"); // `|` is separator in a query string, equivalently `single|myFunction` // Adds the following code to the file's source: // // ... // Code // ... // // module.exports = myFunction; myFunction("Hello world"); ``` ```js import { myFunctionAlias } from "exports-loader?exports=named|myFunction|myFunctionAlias!./file.js"; // `|` is separator in a query string, equivalently `named|myFunction|myFunctionAlias` // Adds the following code to the file's source: // // ... // Code // ... // // exports { myFunction as myFunctionAlias }; myFunctionAlias("Hello world"); ``` Description of string values can be found in the documentation below. ### Using Configuration **webpack.config.js** ```js module.exports = { module: { rules: [ { // You can use `regexp` // test: /vendor\.js/$ test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: "myFunction", }, }, ], }, }; ``` And run `webpack` via your preferred method. ## Options | Name | Type | Default | Description | | :-----------------------: | :---------------------------------------: | :---------: | :-------------------------- | | **[`type`](#type)** | `{String}` | `module` | Format of generated exports | | **[`exports`](#exports)** | `{String\|Object\|Array<String\|Object>}` | `undefined` | List of exports | ### `type` Type: `String` Default: `module` Format of generated exports. Possible values - `commonjs` (CommonJS module syntax) and `module` (ES module syntax). #### `commonjs` **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: "Foo", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = { Foo }; ``` #### `module` **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "module", exports: "Foo", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export { Foo }; ``` ### `exports` Type: `String|Array` Default: `undefined` List of exports. #### `String` Allows to use a string to describe an export. ##### `Syntax` The `|` or `%20` (space) allow to separate the `syntax`, `name` and `alias` of export. String syntax - `[[syntax] [name] [alias]]` or `[[syntax]|[name]|[alias]]`, where: - `[syntax]` (**may be omitted**) - - if `type` is `module`- can be `default` and `named`, - if `type` is `commonjs`- can be `single` and `multiple` - `[name]` - name of an exported value (**required**) - `[alias]` - alias of an exported value (**may be omitted**) Examples: - `[Foo]` - generates `export { Foo };`. - `[default Foo]` - generates `export default Foo;`. - `[named Foo]` - generates `export { Foo };`. - `[named Foo FooA]` - generates `export { Foo as FooA };`. - `[single Foo]` - generates `module.exports = Foo;`. - `[multiple Foo]` - generates `module.exports = { Foo };`. - `[multiple Foo FooA]` - generates `module.exports = { 'FooA': Foo };`. - `[named [name] [name]Alias]` - generates ES module named exports and exports a value equal to the filename under other name., for `single.js` it will be `single` and `singleAlias`, generates `export { single as singleAlias };`. > **Warning** > > You need to set `type: "commonjs"` to use `single` or `multiple` syntaxes. > **Warning** > > Aliases can't be used together with `default` or `single` syntaxes. ##### Examples ###### ES Module Default Export **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: "default Foo", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export default Foo; ``` ###### ES Module Named Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: "named Foo FooA", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export { Foo as FooA }; ``` ###### CommonJS Single Export **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: "single Foo", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = Foo; ``` ###### CommonJS Multiple Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: "multiple Foo FooA", }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = { FooA: Foo }; ``` #### `Object` Allows to use an object to describe an export. Properties: - `syntax` - can be `default` or `named` for the `module` type (`ES modules` module format), and `single` or `multiple` for the `commonjs` type (`CommonJS` module format) (**may be omitted**) - `name` - name of an exported value (**required**) - `alias` - alias of an exported value (**may be omitted**) ##### Examples ###### ES Module Default Export **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: { syntax: "default", name: "Foo", }, }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export default Foo; ``` ###### ES Module Named Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: { syntax: "named", name: "Foo", alias: "FooA", }, }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export { Foo as FooA }; ``` ###### CommonJS Single Export **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: { syntax: "single", name: "Foo", }, }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = Foo; ``` ###### CommonJS Multiple Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: { syntax: "multiple", name: "Foo", alias: "FooA", }, }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = { FooA: Foo }; ``` #### `Array` Allow to specify multiple exports. Each item can be a [`string`](https://github.com/webpack-contrib/exports-loader#string) or an [`object`](https://github.com/webpack-contrib/exports-loader#object). > **Warning** > > Not possible to use `single` and `multiple` syntaxes together due to CommonJS format limitations. > **Warning** > > Not possible to use multiple `default` values due to ES module format limitations. > **Warning** > > Not possible to use multiple `single` values due to CommonJS format limitations. ##### Examples ###### CommonJS Multiple Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { type: "commonjs", exports: ["Foo", "multiple Bar", "multiple Baz BazA"], }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... module.exports = { Foo, Bar, BazA: Bar }; ``` ###### ES Module Default Export And Named Exports Together **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: ["default Foo", "named Bar BarA"], }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export default Foo; export { Bar as BarA }; ``` ###### Named Exports **webpack.config.js** ```js module.exports = { module: { rules: [ { test: require.resolve("./path/to/vendor.js"), loader: "exports-loader", options: { exports: [ { syntax: "named", name: "Foo", alias: "FooA" }, { syntax: "named", name: "Bar" }, "Baz", ], }, }, ], }, }; ``` Generate output: ```js // ... // Code // ... export { Foo as FooA, Bar, Baz }; ``` ## Contributing Please take a moment to read our contributing guidelines if you haven't yet done so. [CONTRIBUTING](./.github/CONTRIBUTING.md) ## License [MIT](./LICENSE) [npm]: https://img.shields.io/npm/v/exports-loader.svg [npm-url]: https://npmjs.com/package/exports-loader [node]: https://img.shields.io/node/v/exports-loader.svg [node-url]: https://nodejs.org [tests]: https://github.com/webpack-contrib/exports-loader/workflows/exports-loader/badge.svg [tests-url]: https://github.com/webpack-contrib/exports-loader/actions [cover]: https://codecov.io/gh/webpack-contrib/exports-loader/branch/master/graph/badge.svg [cover-url]: https://codecov.io/gh/webpack-contrib/exports-loader [discussion]: https://img.shields.io/github/discussions/webpack/webpack [discussion-url]: https://github.com/webpack/webpack/discussions [size]: https://packagephobia.now.sh/badge?p=exports-loader [size-url]: https://packagephobia.now.sh/result?p=exports-loader