code: function replace2x(path) {
              // src/a@2x.jpg => a.png
              var reg_replace2x = /@2x/ig;
              var sigle_x_path = path.replace(reg_replace2x, '');
              return sigle_x_path.substring(sigle_x_path.lastIndexOf('/') + 1,sigle_x_path.length);
          }
docs: helpers