code: function gnapSidebarSlideUpSlideDown() {
          return {
              beforeAddClass: function (element, className, done) {
                  if (className === 'ng-hide') {
                      element.slideUp(done);
  
                      return function (cancel) {
                          if (cancel) {
                              element.stop();
                          }
                      };
                  }
              },
  
              removeClass: function (element, className, done) {
                  if (className === 'ng-hide') {
                      element.hide();
                      element.slideDown(done);
  
                      return function (cancel) {
                          if (cancel) {
                              return element.stop();
                          }
                      };
                  }
              }
          };
      }
docs: custom animation for ng-hide (slide-up/slide-down)