code: function readableBy(file, user) {
    if (!exists(file)) {
      return readableBy(path.dirname(file), user);
    }
    const userData = findUser(user);
    if (userData.id === 0) {
      return true;
    } else if (userData.id === process.getuid()) {
      return readable(file);
    } else {
      return _accesibleByUser(userData, file, fs.R_OK);
    }
  }
docs: Check whether a file is readable or not by a given user
  @function $file~readableBy
  @param {string} file
  @param {string|number} user - Username or user id to check permissions for
  @returns {boolean}
  @example
  // Check if 'conf/my.cnf' is readable by the 'nobody' user
  $file.readableBy('conf/my.cnf', 'nobody');
  // => false