text: var fs = require('fs');
  var path = require('path');
  
  module.exports = function (dirPath, fileFilter, callback) {
      fs.readdir(dirPath, function (err, list) {
          if (err) return callback(err);
          var listMatch = [];
          var ext = '.' + fileFilter;
          list.forEach(function (file) {
              if (path.extname(file) === ext) {
                  listMatch.push(file);
              }
          });
          return callback(null, listMatch);
      })
  }