old_contents: /*!
   * is-dotfile <https://github.com/jonschlinkert/is-dotfile>
   *
   * Copyright (c) 2015-2017, Jon Schlinkert.
   * Released under the MIT License.
   */
  
  module.exports = function(str) {
    if (str.charCodeAt(0) === 46 /* . */ && str.indexOf('/', 1) === -1) {
      return true;
    }
    var slash = str.lastIndexOf('/');
    return slash !== -1 ? str.charCodeAt(slash + 1) === 46  /* . */ : false;
  };
  
new_contents: /*!
   * is-dotfile <https://github.com/jonschlinkert/is-dotfile>
   *
   * Copyright (c) 2015-2017, Jon Schlinkert.
   * Released under the MIT License.
   */
  
  var dotfileRegex = require('dotfile-regex');
  
  module.exports = function(str) {
    return dotfileRegex().test(str);
  };
  
subject: use dotfile-regex