/usr/lib/nodejs/is-dotfile/index.js is in node-is-dotfile 1.0.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | /*!
 * is-dotfile <https://github.com/regexps/is-dotfile>
 *
 * Copyright (c) 2015 Jon Schlinkert, contributors.
 * Licensed under the MIT license.
 */
module.exports = function(str) {
  if (str.charCodeAt(0) === 46 /* . */ && str.indexOf('/', 1) === -1) {
    return true;
  }
  var last = str.lastIndexOf('/');
  return last !== -1 ? str.charCodeAt(last + 1) === 46  /* . */ : false;
};
 |