Scheduler - The 'Cannot read properties of undefined (reading 'getTim…

…e')' error is thrown on an attempt to drag an outside element if the previous drag operation was canceled (T1263508) (#28582)

packages/devextreme/js/__internal/scheduler/m_appointment_drag_behavior.ts

@@ -130,7 +130,7 @@ export default class AppointmentDragBehavior {
 
       // NOTE: event.cancel may be promise or different type, so we need strict check here.
       if (e.cancel === true) {
-        this.removeDroppableClasses();
+        options.onDragCancel(e);
       }
 
       if (e.cancel !== true && isSchedulerComponent(e.toComponent)) {

packages/devextreme/js/__internal/scheduler/workspaces/m_work_space.ts

@@ -51,6 +51,7 @@ import {
 import WidgetObserver from '../base/m_widget_observer';
 import AppointmentDragBehavior from '../m_appointment_drag_behavior';
 import {
+  APPOINTMENT_DRAG_SOURCE_CLASS,
   DATE_TABLE_CLASS,
   DATE_TABLE_ROW_CLASS,
   FIXED_CONTAINER_CLASS,
@@ -3386,6 +3387,15 @@ const createDragBehaviorConfig = (
     removeDroppableCellClass();
   };
 
+  const onDragCancel = (e) => {
+    if (!isDefaultDraggingMode) {
+      enableDefaultDragging();
+    }
+
+    removeDroppableCellClass();
+    e.itemElement?.removeClass?.(APPOINTMENT_DRAG_SOURCE_CLASS);
+  };
+
   const cursorOffset = options.isSetCursorOffset
     ? () => {
       const $dragElement = $(state.dragElement);
@@ -3402,6 +3412,7 @@ const createDragBehaviorConfig = (
     onDragStart,
     onDragMove,
     onDragEnd,
+    onDragCancel,
     cursorOffset,
     filter: options.filter,
   };

packages/devextreme/testing/testcafe/tests/scheduler/dragAndDrop/T1263508.ts

@@ -0,0 +1,103 @@
+import { ClientFunction, Selector } from 'testcafe';
+import Scheduler from '../../../model/scheduler';
+import { MouseAction, MouseUpEvents } from '../../../helpers/mouseUpEvents';
+import { createWidget } from '../../../helpers/createWidget';
+import url from '../../../helpers/getPageUrl';
+
+fixture.disablePageReloads`Scheduler Drag-and-Drop Fix`
+  .page(url(__dirname, '../../container.html'));
+
+const DRAGGABLE_ITEM_CLASS = 'dx-card';
+const draggingGroupName = 'appointmentsGroup';
+
+const initList = ClientFunction(() => {
+  $('<div>', { id: 'list' }).appendTo('#parentContainer');
+});
+
+const removeList = ClientFunction(() => {
+  $('#list').remove();
+});
+
+const addTasksToList = ClientFunction((tasks) => {
+  tasks.forEach((task) => {
+    $('<div>', {
+      class: 'dx-card',
+      text: task.text,
+    }).appendTo('#list');
+  });
+});
+
+const createItemElement = async (task) => {
+  await createWidget('dxDraggable', {
+    group: draggingGroupName,
+    data: task,
+    clone: true,
+    onDragStart(e) {
+      e.itemData = e.fromData;
+    },
+  }, `.${DRAGGABLE_ITEM_CLASS}:contains(${task.text})`);
+};
+
+test('Scheduler - The \'Cannot read properties of undefined (reading \'getTime\')\' error is thrown on an attempt to drag an outside element if the previous drag operation was canceled', async (t) => {
+  const scheduler = new Scheduler('#container');
+  const draggableAppointment = scheduler.getAppointment('Book').element;
+  const targetCell = scheduler.getDateTableCell(5, 0);
+  const draggableItem = Selector(`.${DRAGGABLE_ITEM_CLASS}`).withText('Brochures');
+
+  await t.expect(scheduler.element.exists).ok();
+
+  await MouseUpEvents.disable(MouseAction.dragToElement);
+
+  await t
+    .dragToElement(draggableAppointment, targetCell)
+    .pressKey('esc');
+
+  await MouseUpEvents.enable(MouseAction.dragToElement);
+
+  await t
+    .expect(draggableItem.exists)
+    .ok()
+    .dragToElement(draggableItem, targetCell);
+
+  const newAppointment = scheduler.getAppointment('Brochures');
+
+  await t
+    .expect(newAppointment.element.exists)
+    .ok();
+}).before(async () => {
+  const tasks = [
+    { text: 'Brochures' },
+  ];
+
+  await initList();
+  await addTasksToList(tasks);
+  await Promise.all(tasks.map((task) => createItemElement(task)));
+  await createWidget('dxScheduler', {
+    timeZone: 'America/Los_Angeles',
+    dataSource: [
+      {
+        text: 'Book',
+        startDate: new Date('2021-04-26T19:00:00.000Z'),
+        endDate: new Date('2021-04-26T20:00:00.000Z'),
+      },
+    ],
+    currentDate: new Date(2021, 3, 26),
+    startDayHour: 9,
+    height: 600,
+    editing: true,
+    appointmentDragging: {
+      group: draggingGroupName,
+      onDragEnd(e) {
+        e.cancel = e.event.ctrlKey;
+      },
+      onRemove(e) {
+        e.component.deleteAppointment(e.itemData);
+      },
+      onAdd(e) {
+        e.component.addAppointment(e.itemData);
+      },
+    },
+  });
+}).after(async () => {
+  await removeList();
+});