Draggable - Add safety guards for Angular SSR and disposal (DevExpress#33775)

Author: aleksei-semikozov

packages/devextreme-angular/src/server/render.ts

@@ -25,6 +25,9 @@ export class DxServerModule {
           temp.innerHTML = renderToString(el);
 
           const mainElement = temp.childNodes[0];
+          if (!mainElement) {
+            return;
+          }
           const childString = mainElement.innerHTML;
 
           for (let i = 0; i < mainElement.attributes.length; i++) {

packages/devextreme/js/__internal/__tests__/draggable_dispose.test.ts

@@ -0,0 +1,19 @@
+import $ from '@js/core/renderer';
+import Sortable from '@js/ui/sortable';
+
+describe('Draggable dispose safety', () => {
+  beforeEach(() => {
+    document.body.innerHTML = '';
+  });
+
+  it('should not crash on _stopAnimator when _scrollAnimator is not initialized', () => {
+    const $container = $('<div>').appendTo(document.body);
+    const sortable = new Sortable($container, {});
+
+    (sortable as any)._scrollAnimator = undefined;
+
+    expect(() => {
+      sortable.dispose();
+    }).not.toThrow();
+  });
+});

packages/devextreme/js/__internal/m_draggable.ts

@@ -439,7 +439,7 @@ class Draggable extends DOMComponent<Draggable, Properties> {
   }
 
   _stopAnimator() {
-    this._scrollAnimator.stop();
+    this._scrollAnimator?.stop();
   }
 
   _addWidgetPrefix(className?) {