TreeView: focus treeview element in selectAllEnabled and items empty (T1294524) (DevExpress#30904)

Author: juleari

packages/devextreme/js/__internal/ui/tree_view/m_tree_view.base.ts

@@ -1638,9 +1638,10 @@ class TreeViewBase extends HierarchicalCollectionWidget<TreeViewBaseProperties>
     }
   }
 
-  focus() {
-    if (this._selectAllEnabled()) {
-      // @ts-expect-error
+  focus(): void {
+    const { items = [] } = this.option();
+    if (this._selectAllEnabled() && items.length) {
+      // @ts-expect-error ts-error
       eventsEngine.trigger(this._$selectAllItem, 'focus');
       return;
     }

packages/devextreme/js/__internal/ui/tree_view/m_tree_view.search.ts

@@ -93,7 +93,8 @@ const TreeViewSearch = TreeViewBase.inherit(searchBoxMixin).inherit({
   _itemContainer(isSearchMode, selectAllEnabled) {
     selectAllEnabled ??= this._selectAllEnabled();
 
-    if (selectAllEnabled) {
+    const { items = [] } = this.option();
+    if (selectAllEnabled && items.length) {
       return this._getNodeContainer();
     }
 

packages/devextreme/testing/tests/DevExpress.ui.widgets/treeViewParts/focusing.js

@@ -300,6 +300,17 @@ QUnit.test('select all item should be focused on treeview focus', function(asser
     assert.ok($selectAllItem.hasClass(FOCUSED_STATE_CLASS));
 });
 
+QUnit.testInActiveWindow('Treeview container should be focused on empty treeview focus (T1294524)', function(assert) {
+    const $treeView = initTree({
+        showCheckBoxesMode: 'selectAll',
+        focusStateEnabled: true,
+    });
+
+    $treeView.dxTreeView('focus');
+
+    assert.strictEqual($treeView.hasClass(FOCUSED_STATE_CLASS), true, 'treeview is focused');
+});
+
 QUnit.test('SelectAll checkbox should be checked with space key', function(assert) {
     if(!isDesktopDevice()) {
         assert.ok(true, 'only on desktops');