/**
 * ExternalApiHelper has the specific use case of generating an API json file from third-party definition files.
 * This class is invoked by the gulp-core-build-typescript gulpfile, where the external package names are
 * hard wired.
 * The job of this method is almost the same as the API Extractor task that is executed on first party packages,
 * with the exception that all packages analyzed here are external packages with definition files.
 *
 * @beta
 */
export default class ExternalApiHelper {
    /**
     * @param rootDir - the absolute path containing a 'package.json' file and is also a parent of the
     * external package file. Ex: build.absolute_build_path.
     * @param libFolder - the path to the lib folder relative to the rootDir, this is where
     * 'external-api-json/external_package.api.json' file will be written. Ex: 'lib'.
     * @param externalPackageFilePath - the path to the '*.d.ts' file of the external package relative to the rootDir.
     * Ex: 'resources/external-api-json/es6-collection/index.t.ds'
     */
    static generateApiJson(rootDir: string, libFolder: string, externalPackageFilePath: string): void;
}