code: function(file, regFilter, cb) {
  
  		cb = arguments[arguments.length-1];
  		if(!file || !fs.existsSync(file)) {
  			cb(true);
  			return ;
  		}
  
  
  		// Apply filter
  		var fileName = path.basename(file);
  		if(regFilter && regFilter.test && regFilter.test(fileName)) {
  			return ;
  		}
  
  		if(fs.lstatSync(file).isFile()) {
  			cb(false, file);
  			return ;
  		} else if(fs.lstatSync(file).isDirectory()) {
  			// is directory
  			(fs.readdirSync(file)).forEach(function(item) {
  				utils.traverseFolderSync(path.join(file, item), regFilter, cb);
  			});
  		}
  	}
docs: Traverse the folder =================== @param file {string} @param regFilter {RegExp} exclude files @param cb {function} (err, file)