code: function(dirPath, callback) {
  
              if (!dirPath || typeof dirPath !== 'string') {
                  callback("dirPath must be a string");
              } else {
                  fs.readdir(dirPath, function(err, list) {
                      var dir = [];
  
                      if (err) {
                          callback(err, null);
                      } else {
                          list.forEach(function(item) {
                              dir.push(readNode(path.join(dirPath, item)));
                          });
  
                          callback(null, dir);
                      }
  
                  });
              }
  
          }
docs: API 
  readDir
  
  Return dir content
  
  @param {String}      dirPath     A path
  @param {Function}    callback    Function to chain with result array