rolldown-license-plugin

Rolldown plugin to extract dependency licenses and optionally validate them. Zero dependencies, optimized for performance.

Usage

import {defineConfig} from "rolldown";
import {licensePlugin} from "rolldown-license-plugin";

export default defineConfig({
  plugins: [
    licensePlugin({
      done(deps, context) {
        context.emitFile({
          type: "asset",
          fileName: "licenses.txt",
          source: deps.map(({name, version, license, licenseText}) => {
            return `${name}@${version} - ${license}\n${licenseText}`;
          }).join("\n\n"),
        });
      },
    }),
  ],
});

This also works with Vite, using defineConfig from vite.

API

licensePlugin(opts)

Returns the plugin.

opts.done

Type: (licenses: LicenseInfo[], context: PluginContext) => void | Promise<void>

Callback invoked during generateBundle with the collected license data. The context parameter provides access to rolldown's plugin context, including emitFile.

opts.match

Type: RegExp
Default: /^((UN)?LICEN(S|C)E|COPYING).*$/i

Regex to match license filenames in package directories.

opts.wrapLicenseText

Type: number
Default: undefined (no wrapping)

When set, word-wrap licenseText to this column width.

opts.allow

Type: (license: LicenseInfo) => boolean
Default: undefined (no validation)

Validate each dependency's license. Return false to reject it. By default, rejected dependencies are reported via the rolldown plugin context's warn. Use failOnViolation and failOnUnlicensed to throw build errors instead.

opts.failOnViolation

Type: boolean
Default: false

Throw a build error when a dependency has an incompatible license.

opts.failOnUnlicensed

Type: boolean
Default: false

Throw a build error when a dependency does not specify any license.

LicenseInfo

type LicenseInfo = {
  name: string;        // package name
  version: string;     // package version, or ""
  license: string;     // SPDX license identifier from package.json, or ""
  licenseText: string; // contents of LICENSE/COPYING file, or ""
};

wrap(text, width)

Function to word-wrap text to a certain column width. Returns the wrapped string.

License

© silverwind, distributed under BSD-2-Clause.