fixes the tests

src/PostIt/PostIt.Tests/MainPageButtonsTests.cs

@@ -9,6 +9,7 @@ using PostIt.Services;
 using PostIt.ViewModels;
 using PostIt.Views;
 using PostIt.Views.Blogs;
+using PostIt.Helpers;
 
 namespace PostIt.Tests;
 
@@ -117,7 +118,10 @@ public class MainPageButtonsTests
         var app = (PostIt.App)Application.Current!;
 
         app.AttachMainWindow(window);
+
         window.NavRoot.PushAsync(page).GetAwaiter().GetResult();
+        var mainWindow = new Window { Content = window };
+        mainWindow.Show();
         return (window, page);
     }
 
@@ -147,7 +151,7 @@ public class MainPageButtonsTests
     }
 
     [AvaloniaFact]
-    public void Acl_button_click_pushes_a_page_onto_nav_stack()
+    public async Task Acl_button_click_pushes_a_page_onto_nav_stack()
     {
         // Arrange: a VM whose SelectedPost is non-null so
         // CanManageAcl evaluates to true and the button is
@@ -180,7 +184,7 @@ public class MainPageButtonsTests
     }
 
     [AvaloniaFact]
-    public void Circles_button_click_pushes_a_page_onto_nav_stack()
+    public async Task Circles_button_click_pushes_a_page_onto_nav_stack()
     {
         // Arrange: OpenCircles has no CanExecute guard today —
         // any click should fire it and push the page.

src/PostIt/PostIt.Tests/MainPageSaveTests.cs

@@ -64,9 +64,7 @@ public class MainPageSaveTests
         const string typed = "Mon premier billet";
         titleBox.Text = typed;
 
-        var saveButton = window.GetVisualDescendants()
+        var saveButton = page.SaveButton;
-            .OfType<Button>()
-            .Single(b => b.Content as string == "Save");
         saveButton.Command!.Execute(null);
 
         // The Save command is async (RelayCommand over Task) but

src/PostIt/PostIt/App.axaml.cs

@@ -46,35 +46,48 @@ public partial class App : Application
 
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            var window = ServiceProvider.GetRequiredService<MainWindow>();
+            InitializeClassicDesktopLifetime(settings, desktop);
-            desktop.MainWindow = window;
-            View = window.MainView;
-            this.ConfigureRootView(window.MainView);
-
-            ApplyDarkMode(settings);
         }
         else if (ApplicationLifetime is IActivityApplicationLifetime singleViewFactoryApplicationLifetime)
         {
-            singleViewFactoryApplicationLifetime.MainViewFactory =
+            InitializeActivityLifetime(settings, singleViewFactoryApplicationLifetime);
-                () =>
-                {
-                    View = ServiceProvider.GetRequiredService<MainView>();
-                    this.ConfigureRootView(View);
-                    ApplyDarkMode(settings);
-                    return View;
-                };
         }
         else if (ApplicationLifetime is ISingleViewApplicationLifetime singleViewPlatform)
         {
-            singleViewPlatform.MainView = View = ServiceProvider.GetRequiredService<MainView>();
+            InitializeSingleViewLifetime(settings, singleViewPlatform);
-            ConfigureRootView(View);
-            ApplyDarkMode(settings);
         }
 
         base.OnFrameworkInitializationCompleted();
     }
 
-private void ConfigureRootView(MainView rootView)
+    public void InitializeSingleViewLifetime(Settings settings, ISingleViewApplicationLifetime singleViewPlatform)
+    {
+        singleViewPlatform.MainView = View = ServiceProvider!.GetRequiredService<MainView>();
+        ConfigureRootView(View);
+        ApplyDarkMode(settings);
+    }
+
+    public void InitializeActivityLifetime(Settings settings, IActivityApplicationLifetime singleViewFactoryApplicationLifetime)
+    {
+        singleViewFactoryApplicationLifetime.MainViewFactory =
+                        () =>
+                        {
+                            this.ConfigureRootView(ServiceProvider!.GetRequiredService<MainView>());
+                            ApplyDarkMode(settings);
+                            return View!;
+                        };
+    }
+
+    public void InitializeClassicDesktopLifetime(Settings settings, IClassicDesktopStyleApplicationLifetime desktop)
+    {
+        var window = ServiceProvider!.GetRequiredService<MainWindow>();
+        desktop.MainWindow = window;
+        this.ConfigureRootView(window.MainView);
+
+        ApplyDarkMode(settings);
+    }
+
+    public void ConfigureRootView(MainView rootView)
 {
     // Déclencher le Boot une seule fois lors du chargement du contrôle à l'écran.
     rootView.AttachedToVisualTree += async (_, _) => await BootOnceAsync();
@@ -87,6 +100,7 @@ private void ConfigureRootView(MainView rootView)
     };
 
     rootView.SessionBanner.DataContext = sessionStatus;
+    this.View = rootView;
 }
 
     private async Task BootOnceAsync()

src/PostIt/PostIt/Helpers/ViewModelBaseHelpers.cs

@@ -8,7 +8,7 @@ namespace PostIt.Helpers;
 
 public static class ViewModelBaseHelpers
 {
-    public static async Task PushPageAsync(this App app, ViewModelBase vm)
+    public static async Task<Page> PushPageAsync(this App app, ViewModelBase vm)
     {
         var window = app.View;
         if (window is null)
@@ -43,9 +43,11 @@ public static class ViewModelBaseHelpers
         var stack = window.NavRoot.NavigationStack;
         if (stack.Count > 0 && ReferenceEquals(stack[stack.Count - 1], page))
         {
-            return;
+            return page;
         }
 
         await window.NavRoot.PushAsync(page);
+
+        return page;
     }
 }

src/PostIt/PostIt/ViewModels/Layout/HomePageViewModel.cs

@@ -31,8 +31,9 @@ public class HomePageViewModel : ViewModelBase
 
         OpenActivities = new AsyncRelayCommand(OpenActivitiesAsync);
         OpenProviderRequests = new AsyncRelayCommand(OpenProviderRequestsAsync);
+        OpenBlogs = new AsyncRelayCommand(App.PushBlogsPageAsync);
     }
-    public IAsyncRelayCommand OpenBlogs { get; } = new AsyncRelayCommand(App.PushBlogsPageAsync);
+    public IAsyncRelayCommand OpenBlogs { get; }
     public IAsyncRelayCommand OpenActivities { get; }
     public IAsyncRelayCommand OpenProviderRequests { get; }