code: function isFileExtension(filepath, extension) {
  			return typeof filepath === 'string' && path.extname(filepath) === extension && fs.existsSync(filepath) &&
  				fs.lstatSync(filepath).isFile()
  				;
  		}
docs: Check whether specified path exists, is a file and has .js extension.
  
  @param {String} filepath Path of a file.
  @param {String} extension Extension to check for, including the`.`.
  @return {Boolean}