ContextMenu: Fix scrollable container height calculation for theme-less usage (T1258002) (DevExpress#28981)

Author: nikkithelegendarypokemonster

packages/devextreme/js/__internal/ui/context_menu/m_context_menu.ts

@@ -28,7 +28,8 @@ import type { Properties as OverlayProperties } from '@js/ui/overlay';
 import type dxOverlay from '@js/ui/overlay';
 import Overlay from '@js/ui/overlay/ui.overlay';
 import Scrollable from '@js/ui/scroll_view/ui.scrollable';
-import { current as currentTheme, isMaterialBased } from '@js/ui/themes';
+// @ts-expect-error
+import { current as currentTheme, isGeneric } from '@js/ui/themes';
 import MenuBase from '@ts/ui/context_menu/m_menu_base';
 
 const DX_MENU_CLASS = 'dx-menu';
@@ -724,7 +725,7 @@ class ContextMenu extends MenuBase {
   }
 
   _getSubmenuBorderWidth() {
-    return isMaterialBased(currentTheme()) ? 0 : BORDER_WIDTH;
+    return isGeneric(currentTheme()) ? BORDER_WIDTH : 0;
   }
 
   _showSubmenu($item: dxElementWrapper): void {

packages/devextreme/testing/tests/DevExpress.ui.widgets/contextMenu.tests.js

@@ -11,6 +11,7 @@ import contextMenuEvent from 'events/contextmenu';
 import holdEvent from 'events/hold';
 import { isRenderer } from 'core/utils/type';
 import config from 'core/config';
+import themes from 'ui/themes';
 import keyboardMock from '../../helpers/keyboardMock.js';
 import ariaAccessibilityTestHelper from '../../helpers/ariaAccessibilityTestHelper.js';
 
@@ -271,6 +272,24 @@ QUnit.module('Rendering', moduleConfig, () => {
 
         assert.strictEqual($icon.attr('alt'), 'dxContextMenu item icon');
     });
+
+    QUnit.test('contextMenu maxHeight should not include border width if no theme is specified (T1258002)', function(assert) {
+        const stub = sinon.stub(themes, 'current').returns('none');
+
+        try {
+            const contextMenu = new ContextMenu(this.$element, {
+                items: [{ text: 'Test Item' }],
+                visible: true
+            });
+
+            const overlayMaxHeight = contextMenu.itemsContainer().css('maxHeight');
+            const contentHeight = $(`.${DX_CONTEXT_MENU_ITEMS_CONTAINER_CLASS}`).outerHeight();
+
+            assert.strictEqual(overlayMaxHeight, `${contentHeight}px`, 'overlay maxHeight does not include border width');
+        } finally {
+            stub.restore();
+        }
+    });
 });
 
 QUnit.module('Repaint', moduleConfig, () => {