# Documentation ## Basic Setup Below is an example of how to add the plugin to a webpack config: ```javascript const LicenseWebpackPlugin = require('license-webpack-plugin').LicenseWebpackPlugin; module.exports = { plugins: [ new LicenseWebpackPlugin() ] }; ``` ## Configuration * **`stats`** - toggle warnings and errors on/off (default: report warnings and errors) Example: ```javascript new LicenseWebpackPlugin({ stats: { warnings: true, errors: true } }); ``` * **`licenseInclusionTest`** - filter which licenses get included in the report (default: capture all licenses) Example: ```javascript new LicenseWebpackPlugin({ licenseInclusionTest: (licenseType) => (licenseType === 'MIT') }); ``` Notes: All license identifiers in npm packages are supposed to follow SPDX format. If your requirements are very specific, it is recommended to set up this option using the [`spdx-satisfies`](https://www.npmjs.com/package/spdx-satisfies) package. The plugin does not provide the `spdx-satisfies` package, so you must install it separately if you want to use it. Example using `spdx-satisfies`: ```javascript const satisfies = require('spdx-satisfies'); new LicenseWebpackPlugin({ licenseInclusionTest: (licenseType) => satisfies(licenseType, '(ISC OR MIT)') }); ``` * **`outputFilename`** - customize the license report filename (default: `'[name].licenses.txt'`) Example: ```javascript new LicenseWebpackPlugin({ outputFilename: '[name].[hash].licenses.txt' }); ``` * **`unacceptableLicenseTest`** - error out on unacceptable license (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ unacceptableLicenseTest: (licenseType) => (licenseType === 'GPL') }); ``` * **`handleUnacceptableLicense`** - do something when an unacceptable license is found (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ unacceptableLicenseTest: (licenseType) => (licenseType === 'GPL'), handleUnacceptableLicense: (packageName, licenseType) => { // do something here } }); ``` * **`excludedPackageTest`** - exclude packages (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ excludedPackageTest: (packageName) => packageName === 'excluded-package' }); ``` * **`perChunkOutput`** - control whether or not the license files are generated per chunk or are combined into one file (default: `true`) Example: ```javascript new LicenseWebpackPlugin({ perChunkOutput: false // combine all license information into one file }); ``` * **`addBanner`** - write a banner to the top of each js file (default: `false`) Example: ```javascript new LicenseWebpackPlugin({ addBanner: true }); ``` * **`licenseTypeOverrides`** - override the license type for specific packages (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ licenseTypeOverrides: { foopkg: 'MIT' } }); ``` * **`licenseTextOverrides`** - override the license text for specific packages (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ licenseTextOverrides: { foopkg: 'License text for foopkg' } }); ``` * **`licenseFileOverrides`** - override the license filename for specific packages (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ licenseFileOverrides: { foopkg: 'The-License.txt' } }); ``` Notes: The license filename is resolved relative to the package directory. * **`renderLicenses`** - change the format / contents of the generated license file (default: print package name, license type, and license text) Example: ```javascript new LicenseWebpackPlugin({ renderLicenses: (modules) => { console.log(modules[0].packageJson, modules[0].licenseId, modules[0].licenseText); return JSON.stringify(modules); } }); ``` * **`renderBanner`** - change the format / contents of the banner written to the top of each js file (default: print message indicating license filename) Example: ```javascript new LicenseWebpackPlugin({ addBanner: true, renderBanner: (filename, modules) => { console.log(modules); return '/*! licenses are at ' + filename + '*/'; } }); ``` * **`handleMissingLicenseText`** - do something when license text is missing from a package (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ handleMissingLicenseText: (packageName, licenseType) => { console.log('Cannot find license for ' + packageName); return 'UNKNOWN'; } }); ``` Notes: You can return your own license text from this function, but you should prefer using `licenseTextOverrides` first. * **`licenseTemplateDir`** - use fallback license files for when a package is missing a license file (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ licenseTemplateDir: path.resolve(__dirname, 'licenseTemplates') }); ``` Notes: This option specifies a directory containing `.txt` files containing the license text based on the license type. (e.g. `MIT.txt`). Templates can be found [here](https://github.com/spdx/license-list). * **`chunkIncludeExcludeTest`** - control which chunks gets processed by the plugin (default: all chunks get processed) Example: ```javascript new LicenseWebpackPlugin({ chunkIncludeExcludeTest: { exclude: ['foo'], include: ['bar'] } }); ``` Example: ``` new LicenseWebpackPlugin({ chunkIncludeExcludeTest: (chunkName) => chunkName.startsWith('abc') }); ``` Notes: If there is a duplicate entry in both the `exclude` and `include` array, the duplicated entry will be excluded. * **`modulesDirectories`** - limit which directories get scanned for license files (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ modulesDirectories: [ path.resolve(__dirname, 'node_modules') ] }); ``` * **`additionalChunkModules`** - add additional node modules to a chunk (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ additionalChunkModules: { main: [ { name: 'somepkg' directory: path.join(__dirname, 'node_modules', 'somepkg') } ] } }); ``` * **`additionalModules`** - add additional node modules to the scan (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ additionalModules: [ { name: 'somepkg' directory: path.join(__dirname, 'node_modules', 'somepkg') } ] }); ``` * **`preferredLicenseTypes`** - help the plugin decide which license type to pick in case a package specifies multiple licenses (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ preferredLicenseTypes: ['MIT', 'ISC'] }); ``` * **`handleLicenseAmbiguity`** - do something when the plugin finds ambiguous license types (default: pick first license type) Example: ```javascript new LicenseWebpackPlugin({ handleLicenseAmbiguity: (packageName, licenses) => { console.log(packageName); console.log(licenses[0].url); return licenses[0].type; } }); ``` Notes: This function is called whenever a license type could not be determined when a package uses the deprecated `licenses` field (which is an array of license types) in its package.json. It should return the license type to use. By default, the plugin prints a warning message to the console and chooses the first license type. You should use the `preferredLicenseTypes` option instead of this one. * **`handleMissingLicenseType`** - do something when a package is missing a license type (default: disabled) Example: ```javascript new LicenseWebpackPlugin({ handleMissingLicenseType: (packageName) => { console.log(packageName); return null; } }); ``` Notes: You can return a license type from this function, but it is a better idea to use the `licenseTypeOverides` option.