function readFile(inputFileSystem, path) {
  return new Promise((resolve, reject) => {
    inputFileSystem.readFile(
      path,
      /**
       * @param {null | undefined | NodeJS.ErrnoException} err
       * @param {undefined | string | Buffer} data
       */
      (err, data) => {
        if (err) {
          reject(err);

          return;
        }

        resolve(/** @type {string | Buffer} */ (data));
      },
    );
  });
}
@param {InputFileSystem} inputFileSystem
@param {string} path
@return {Promise<string | Buffer>}