Draggable - Add dispose safety test for missing scrollAnimator

Author: aleksei-semikozov

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();
+  });
+});