From f645b2ffa708a9a78315e7b72d14ae8f47dcac6f Mon Sep 17 00:00:00 2001
From: Bozhidara Pachilova <bozhidara.pp@gmail.com>
Date: Wed, 26 Nov 2025 11:10:13 +0200
Subject: [PATCH 1/3] test(grid-col-groups): add test for no data + focus grid
 body

---
 .../grids/grid/src/column-group.spec.ts       | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/projects/igniteui-angular/grids/grid/src/column-group.spec.ts b/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
index dfbbbaaaac2..8cc17811d29 100644
--- a/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
+++ b/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
@@ -203,6 +203,27 @@ describe('IgxGrid - multi-column headers #grid', () => {
             }
         }));
 
+        it('The ariaHidden getter should not throw when the grid has no active node (#16517)', fakeAsync(() => {
+            fixture = TestBed.createComponent(BlueWhaleGridComponent) as ComponentFixture<BlueWhaleGridComponent>;
+            tick();
+            fixture.detectChanges();
+
+            // The grid active node will be null if there is no data and the body is focused
+            grid = fixture.componentInstance.grid;
+            grid.data = [];
+
+            tick();
+            fixture.detectChanges();
+
+            const gridContent = GridFunctions.getGridContent(fixture);
+
+            expect(async () => {
+                gridContent.triggerEventHandler('focus', null);
+                await wait(400);
+                fixture.detectChanges();
+            }).not.toThrow();
+        }));
+
         it('Should render dynamic column group header correctly (#12165).', () => {
             fixture = TestBed.createComponent(BlueWhaleGridComponent) as ComponentFixture<BlueWhaleGridComponent>;
             (fixture as ComponentFixture<BlueWhaleGridComponent>).componentInstance.firstGroupRepeats = 1;

From b00dca1757a847c3569ebf49e0223fc68927cf90 Mon Sep 17 00:00:00 2001
From: Bozhidara Pachilova <bozhidara.pp@gmail.com>
Date: Wed, 26 Nov 2025 11:21:02 +0200
Subject: [PATCH 2/3] fix(grid): add null check for activeNode

---
 .../grids/core/src/headers/grid-header-group.component.ts       | 2 +-
 .../grids/core/src/headers/grid-header-row.component.ts         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/projects/igniteui-angular/grids/core/src/headers/grid-header-group.component.ts b/projects/igniteui-angular/grids/core/src/headers/grid-header-group.component.ts
index 07595de14aa..9a5de67f9be 100644
--- a/projects/igniteui-angular/grids/core/src/headers/grid-header-group.component.ts
+++ b/projects/igniteui-angular/grids/core/src/headers/grid-header-group.component.ts
@@ -151,7 +151,7 @@ export class IgxGridHeaderGroupComponent implements DoCheck {
      * @hidden
      */
     public get ariaHidden(): boolean {
-        return this.grid.hasColumnGroups && (this.column.hidden || this.grid.navigation.activeNode.row !== -1);
+        return this.grid.hasColumnGroups && (this.column.hidden || this.grid.navigation.activeNode?.row !== -1);
     }
 
     /**
diff --git a/projects/igniteui-angular/grids/core/src/headers/grid-header-row.component.ts b/projects/igniteui-angular/grids/core/src/headers/grid-header-row.component.ts
index 93ab924c2fd..6646a57fb4f 100644
--- a/projects/igniteui-angular/grids/core/src/headers/grid-header-row.component.ts
+++ b/projects/igniteui-angular/grids/core/src/headers/grid-header-row.component.ts
@@ -123,7 +123,7 @@ export class IgxGridHeaderRowComponent implements DoCheck {
     * @internal
     */
     public get isLeafHeaderAriaHidden(): boolean {
-        return this.grid.navigation.activeNode.row === -1;
+        return this.grid.navigation.activeNode?.row === -1;
     }
 
     /** The virtualized part of the header row containing the unpinned header groups. */

From 55755e45905d194fcb293688caf43d44aa4eafc2 Mon Sep 17 00:00:00 2001
From: Bozhidara Pachilova <35433937+ddaribo@users.noreply.github.com>
Date: Wed, 26 Nov 2025 11:38:18 +0200
Subject: [PATCH 3/3] Update
 projects/igniteui-angular/grids/grid/src/column-group.spec.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 projects/igniteui-angular/grids/grid/src/column-group.spec.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/projects/igniteui-angular/grids/grid/src/column-group.spec.ts b/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
index 8cc17811d29..232dc7f0d15 100644
--- a/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
+++ b/projects/igniteui-angular/grids/grid/src/column-group.spec.ts
@@ -217,9 +217,9 @@ describe('IgxGrid - multi-column headers #grid', () => {
 
             const gridContent = GridFunctions.getGridContent(fixture);
 
-            expect(async () => {
+            expect(() => {
                 gridContent.triggerEventHandler('focus', null);
-                await wait(400);
+                tick(400);
                 fixture.detectChanges();
             }).not.toThrow();
         }));