Add tests

src/Controls/tests/DeviceTests/Elements/Modal/ModalTests.Windows.cs

@@ -68,21 +68,35 @@ await CreateHandlerAndAddToWindow<IWindowHandler>(window,
 					var rootView = handler.PlatformView.Content;
 					ContentPage modalPage = new ContentPage();
 
+					var previousPageNavigationRootManager = navPage.CurrentPage
+						.FindMauiContext()
+						.GetNavigationRootManager();
+
+					var previousWindowRootView = previousPageNavigationRootManager.RootView as WindowRootView;
+
 					await navPage.CurrentPage.Navigation.PushModalAsync(modalPage);
 					await OnLoadedAsync(modalPage);
 
 					var modalNavigationRootManager = modalPage
 						.FindMauiContext()
 						.GetNavigationRootManager();
 
-
 					var mauiWindow = (MauiWinUIWindow)handler.PlatformView;
 					Assert.Equal("Original Title", mauiWindow.Title);
 					Assert.Equal(modalNavigationRootManager.WindowTitle, mauiWindow.Title);
 
+					// Ensure previous page has hidden its titlebar
+					Assert.True(previousWindowRootView.AppTitleBarContainer.Visibility == UI.Xaml.Visibility.Collapsed);
+					Assert.True(previousWindowRootView.NavigationViewControl?.ButtonHolderGrid.Visibility == UI.Xaml.Visibility.Collapsed);
+
 					window.Title = "Update Title";
 					Assert.Equal("Update Title", mauiWindow.Title);
 					Assert.Equal(modalNavigationRootManager.WindowTitle, mauiWindow.Title);
+
+					// Ensure titlebar is visible after popping modal
+					var modalWindowRootView = modalNavigationRootManager.RootView as WindowRootView;
+					Assert.True(modalWindowRootView.AppTitleBarContainer.Visibility == UI.Xaml.Visibility.Visible);
+					Assert.True(modalWindowRootView.NavigationViewControl.ButtonHolderGrid.Visibility == UI.Xaml.Visibility.Visible);
 				});
 		}
 
@@ -130,6 +144,11 @@ await CreateHandlerAndAddToWindow(window,
 					Assert.Equal(UpdatedTitle, mauiWindow.Title);
 					Assert.Equal(UpdatedTitle, currentNavigationRootManager.WindowTitle);
 					Assert.Equal(UpdatedTitle, modalNavigationRootManager.WindowTitle);
+
+					// Ensure titlebar is visible after popping modal
+					var windowRootView = currentNavigationRootManager.RootView as WindowRootView;
+					Assert.True(windowRootView.AppTitleBarContainer.Visibility == UI.Xaml.Visibility.Visible);
+					Assert.True(windowRootView.NavigationViewControl.ButtonHolderGrid.Visibility == UI.Xaml.Visibility.Visible);
 				}));
 		}
 	}