Make sure that tests inherit from ScropedTestBase (#18690)

tests/Avalonia.Controls.UnitTests/ApplicationTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ApplicationTests
+    public class ApplicationTests : ScopedTestBase
     {
         [Fact]
         public void Throws_ArgumentNullException_On_Run_If_MainWindow_Is_Null()

tests/Avalonia.Controls.UnitTests/AutoCompleteBoxTests.cs

@@ -16,7 +16,7 @@ using Moq;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class AutoCompleteBoxTests
+    public class AutoCompleteBoxTests : ScopedTestBase
     {
         [Fact]
         public void Search_Filters()

tests/Avalonia.Controls.UnitTests/Automation/ControlAutomationPeerTests.cs

@@ -2,6 +2,7 @@
 using Avalonia.Automation.Peers;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Templates;
+using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Xunit;
 
@@ -11,7 +12,7 @@ namespace Avalonia.Controls.UnitTests.Automation
 {
     public class ControlAutomationPeerTests
     {
-        public class Children
+        public class Children : ScopedTestBase
         {
             [Fact]
             public void Creates_Children_For_Controls_In_Visual_Tree()
@@ -149,7 +150,7 @@ namespace Avalonia.Controls.UnitTests.Automation
             }
         }
 
-        public class Parent
+        public class Parent : ScopedTestBase
         {
             [Fact]
             public void Connects_Peer_To_Tree_When_GetParent_Called()

tests/Avalonia.Controls.UnitTests/Avalonia.Controls.UnitTests.csproj

@@ -20,8 +20,7 @@
     <ProjectReference Include="..\..\src\Avalonia.Base\Avalonia.Base.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Controls\Avalonia.Controls.csproj" />
     <ProjectReference Include="..\Avalonia.UnitTests\Avalonia.UnitTests.csproj" />
-  </ItemGroup>
-  <ItemGroup>
+    <Compile Include="../Shared/ScopedSanityCheck.cs"/>
     <Service Include="{82a7f48d-3b50-4b1e-b82e-3ada8210c358}" />
   </ItemGroup>
 </Project>

tests/Avalonia.Controls.UnitTests/BorderTests.cs

@@ -8,7 +8,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class BorderTests
+    public class BorderTests : ScopedTestBase
     {
         [Fact]
         public void Measure_Should_Return_BorderThickness_Plus_Padding_When_No_Child_Present()
@@ -46,7 +46,7 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Rect(6, 6, 0, 0), content.Bounds);
         }
         
-        public class UseLayoutRounding
+        public class UseLayoutRounding : ScopedTestBase
         {
             [Fact]
             public void Measure_Rounds_Padding()

tests/Avalonia.Controls.UnitTests/CalendarDatePickerTests.cs

@@ -11,7 +11,7 @@ using System.Globalization;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class CalendarDatePickerTests
+    public class CalendarDatePickerTests : ScopedTestBase
     {
         private static bool CompareDates(DateTime first, DateTime second)
         {

tests/Avalonia.Controls.UnitTests/CalendarTests.cs

@@ -3,10 +3,11 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using Avalonia.UnitTests;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class CalendarTests
+    public class CalendarTests : ScopedTestBase
     {
         private static bool CompareDates(DateTime first, DateTime second)
         {

tests/Avalonia.Controls.UnitTests/CanvasTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class CanvasTests
+    public class CanvasTests : ScopedTestBase
     {
         [Fact]
         public void Left_Property_Should_Work()

tests/Avalonia.Controls.UnitTests/CarouselTests.cs

@@ -14,7 +14,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class CarouselTests
+    public class CarouselTests : ScopedTestBase
     {
         [Fact]
         public void First_Item_Should_Be_Selected_By_Default()

tests/Avalonia.Controls.UnitTests/ClassesTests.cs

@@ -1,9 +1,10 @@
 using System;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ClassesTests
+    public class ClassesTests : ScopedTestBase
     {
         [Fact]
         public void Duplicates_Should_Not_Be_Added()

tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs

@@ -16,7 +16,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ComboBoxTests
+    public class ComboBoxTests : ScopedTestBase
     {
         MouseTestHelper _helper = new MouseTestHelper();
         

tests/Avalonia.Controls.UnitTests/ContentControlTests.cs

@@ -15,7 +15,7 @@ using System.Collections.Generic;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ContentControlTests
+    public class ContentControlTests : ScopedTestBase
     {
         [Fact]
         public void Template_Should_Be_Instantiated()

tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs

@@ -13,7 +13,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ContextMenuTests
+    public class ContextMenuTests : ScopedTestBase
     {
         private Mock<IPopupImpl> popupImpl;
         private MouseTestHelper _mouse = new MouseTestHelper();

tests/Avalonia.Controls.UnitTests/DatePickerTests.cs

@@ -15,7 +15,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class DatePickerTests
+    public class DatePickerTests : ScopedTestBase
     {
         [Fact]
         public void SelectedDateChanged_Should_Fire_When_SelectedDate_Set()

tests/Avalonia.Controls.UnitTests/DecoratorTests.cs

@@ -6,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class DecoratorTests
+    public class DecoratorTests : ScopedTestBase
     {
         [Fact]
         public void Setting_Content_Should_Set_Child_Controls_Parent()
@@ -118,7 +118,7 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Size(16, 16), target.DesiredSize);
         }
 
-        public class UseLayoutRounding
+        public class UseLayoutRounding : ScopedTestBase
         {
             [Fact]
             public void Measure_Rounds_Padding()

tests/Avalonia.Controls.UnitTests/DesktopStyleApplicationLifetimeTests.cs

@@ -14,7 +14,7 @@ using Xunit;
 namespace Avalonia.Controls.UnitTests
 {
     
-    public class DesktopStyleApplicationLifetimeTests
+    public class DesktopStyleApplicationLifetimeTests : ScopedTestBase
     {
         IDispatcherImpl CreateDispatcherWithInstantMainLoop()
         {

tests/Avalonia.Controls.UnitTests/DockPanelTests.cs

@@ -1,8 +1,9 @@
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class DockPanelTests
+    public class DockPanelTests : ScopedTestBase
     {
         [Fact]
         public void DockPanel_Without_Child()

tests/Avalonia.Controls.UnitTests/FlyoutTests.cs

@@ -18,7 +18,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class FlyoutTests
+    public class FlyoutTests : ScopedTestBase
     {
         protected bool UseOverlayPopups { get; set; }
 

tests/Avalonia.Controls.UnitTests/GridLengthTests.cs

@@ -3,11 +3,12 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class GridLengthTests
+    public class GridLengthTests : ScopedTestBase
     {
         [Fact]
         public void Parse_Should_Parse_Auto()

tests/Avalonia.Controls.UnitTests/HeaderedItemsControlTests .cs

@@ -2,11 +2,12 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.LogicalTree;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class HeaderedItemsControlTests
+    public class HeaderedItemsControlTests : ScopedTestBase
     {
         [Fact]
         public void Control_Header_Should_Be_Logical_Child_Before_ApplyTemplate()

tests/Avalonia.Controls.UnitTests/HotKeyedControlsTests.cs

@@ -71,7 +71,7 @@ namespace Avalonia.Controls.UnitTests
         }
     }
 
-    public class HotKeyedControlsTests
+    public class HotKeyedControlsTests : ScopedTestBase
     {
         private static Window PreparedWindow(object content = null)
         {

tests/Avalonia.Controls.UnitTests/ImageTests.cs

@@ -1,11 +1,12 @@
 using Moq;
 using Avalonia.Media;
 using Avalonia.Media.Imaging;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ImageTests
+    public class ImageTests : ScopedTestBase
     {
         [Fact]
         public void Measure_Should_Return_Correct_Size_For_No_Stretch()

tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs

@@ -24,7 +24,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ItemsControlTests
+    public class ItemsControlTests : ScopedTestBase
     {
         [Fact]
         public void Setting_ItemsSource_Should_Populate_Items()

tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs

@@ -5,11 +5,12 @@ using System.Collections.Specialized;
 using System.Text;
 using Avalonia.Collections;
 using Avalonia.Diagnostics;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ItemsSourceViewTests
+    public class ItemsSourceViewTests : ScopedTestBase
     {
         [Fact]
         public void Only_Subscribes_To_Source_CollectionChanged_When_CollectionChanged_Subscribed()

tests/Avalonia.Controls.UnitTests/LayoutTransformControlTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class LayoutTransformControlTests
+    public class LayoutTransformControlTests : ScopedTestBase
     {
         [Fact]
         public void Measure_On_Scale_x2_Is_Correct()

tests/Avalonia.Controls.UnitTests/ListBoxTests_Multiple.cs

@@ -14,7 +14,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ListBoxTests_Multiple
+    public class ListBoxTests_Multiple : ScopedTestBase
     {
         private MouseTestHelper _helper = new MouseTestHelper();
 

tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs

@@ -16,7 +16,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ListBoxTests_Single
+    public class ListBoxTests_Single : ScopedTestBase
     {
         MouseTestHelper _mouse = new MouseTestHelper();
         

tests/Avalonia.Controls.UnitTests/LoadedTests.cs

@@ -6,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests;
 
-public class LoadedTests
+public class LoadedTests : ScopedTestBase
 {
     [Fact]
     public void Window_Loads_And_Unloads()

tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs

@@ -18,7 +18,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class MaskedTextBoxTests
+    public class MaskedTextBoxTests : ScopedTestBase
     {
         [Fact]
         public void Opening_Context_Menu_Does_not_Lose_Selection()

tests/Avalonia.Controls.UnitTests/MenuItemTests.cs

@@ -15,7 +15,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class MenuItemTests
+    public class MenuItemTests : ScopedTestBase
     {
         private Mock<IPopupImpl> popupImpl;
 

tests/Avalonia.Controls.UnitTests/Mixins/PressedMixinTests.cs

@@ -4,7 +4,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Mixins
 {
-    public class PressedMixinTests
+    public class PressedMixinTests : ScopedTestBase
     {
         private MouseTestHelper _mouse = new MouseTestHelper();
 

tests/Avalonia.Controls.UnitTests/Mixins/SelectableMixinTests.cs

@@ -1,10 +1,11 @@
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Mixins
 {
-    public class SelectableMixinTests
+    public class SelectableMixinTests : ScopedTestBase
     {
         [Fact]
         public void Selected_Class_Should_Not_Initially_Be_Added()

tests/Avalonia.Controls.UnitTests/NameScopeTests.cs

@@ -1,9 +1,10 @@
 using System;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class NameScopeTests
+    public class NameScopeTests : ScopedTestBase
     {
         [Fact]
         public void Register_Registers_Element()

tests/Avalonia.Controls.UnitTests/NumericUpDownTests.cs

@@ -11,7 +11,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class NumericUpDownTests
+    public class NumericUpDownTests : ScopedTestBase
     {
         private static TestServices Services => TestServices.StyledWindow;
 

tests/Avalonia.Controls.UnitTests/PanelTests.cs

@@ -10,7 +10,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class PanelTests
+    public class PanelTests : ScopedTestBase
     {
         [Fact]
         public void Adding_Control_To_Panel_Should_Set_Child_Controls_Parent()

tests/Avalonia.Controls.UnitTests/Platform/DefaultMenuInteractionHandlerTests.cs

@@ -4,13 +4,14 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Input.GestureRecognizers;
 using Avalonia.Interactivity;
+using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Moq;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Platform
 {
-    public class DefaultMenuInteractionHandlerTests
+    public class DefaultMenuInteractionHandlerTests : ScopedTestBase
     {
         static PointerPressedEventArgs CreatePressed(object source) => new PointerPressedEventArgs(source,
             new FakePointer(), (Visual)source, default,0, new PointerPointProperties (RawInputModifiers.None, PointerUpdateKind.LeftButtonPressed),
@@ -21,7 +22,7 @@ namespace Avalonia.Controls.UnitTests.Platform
             new PointerPointProperties(RawInputModifiers.None, PointerUpdateKind.LeftButtonReleased),
             default, MouseButton.Left);
 
-        public class TopLevel
+        public class TopLevel : ScopedTestBase
         {
             [Fact]
             public void Up_Opens_MenuItem_With_SubMenu()
@@ -227,7 +228,7 @@ namespace Avalonia.Controls.UnitTests.Platform
             }
         }
 
-        public class NonTopLevel
+        public class NonTopLevel : ScopedTestBase
         {
             [Fact]
             public void Up_Selects_Previous_MenuItem()
@@ -546,7 +547,7 @@ namespace Avalonia.Controls.UnitTests.Platform
             }
         }
 
-        public class ContextMenu
+        public class ContextMenu : ScopedTestBase
         {
             [Fact]
             public void Down_Selects_Selects_First_MenuItem_When_No_Selection()

tests/Avalonia.Controls.UnitTests/Platform/ScreensTests.cs

@@ -102,10 +102,11 @@ public class ScreensTests : ScopedTestBase
     }
 
     [Fact]
-    public async Task Should_Raise_Event_When_Screen_Changed_From_Another_Thread()
+    public void Should_Raise_Event_When_Screen_Changed_From_Another_Thread()
     {
         using var _ = UnitTestApplication.Start(TestServices.MockThreadingInterface);
 
+        Dispatcher.UIThread.VerifyAccess();
         var hasChangedTimes = 0;
         var screens = new TestScreens();
         screens.Changed = () =>
@@ -114,7 +115,7 @@ public class ScreensTests : ScopedTestBase
             hasChangedTimes += 1;
         };
 
-        await Task.Run(() => screens.PushNewScreens([1, 2]));
+        ThreadRunHelper.RunOnDedicatedThread(() => screens.PushNewScreens([1, 2])).GetAwaiter().GetResult();
         Dispatcher.UIThread.RunJobs();
 
         Assert.Equal(1, hasChangedTimes);

tests/Avalonia.Controls.UnitTests/Platform/StorageProviderHelperTests.cs

@@ -2,11 +2,12 @@ using System;
 using System.Linq;
 using System.Text;
 using Avalonia.Platform.Storage.FileIO;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Platform;
 
-public class StorageProviderHelperTests
+public class StorageProviderHelperTests : ScopedTestBase
 {
     [Fact]
     public void Can_Encode_And_Decode_Bookmark()

tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_InTemplate.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
     /// <summary>
     /// Tests for ContentControls that are hosted in a control template.
     /// </summary>
-    public class ContentPresenterTests_InTemplate
+    public class ContentPresenterTests_InTemplate : ScopedTestBase
     {
         [Fact]
         public void Should_Register_With_Host_When_TemplatedParent_Set()

tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Layout.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Presenters
 {
-    public class ContentPresenterTests_Layout
+    public class ContentPresenterTests_Layout : ScopedTestBase
     {
         [Theory]
         [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Stretch, 0, 0, 100, 100)]
@@ -234,7 +234,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             Assert.Equal(new Rect(32, 32, 0, 0), content.Bounds);
         }
 
-        public class UseLayoutRounding
+        public class UseLayoutRounding : ScopedTestBase
         {
             [Fact]
             public void Measure_Rounds_Padding()

tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Standalone.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
     /// <summary>
     /// Tests for ContentControls that aren't hosted in a control template.
     /// </summary>
-    public class ContentPresenterTests_Standalone
+    public class ContentPresenterTests_Standalone : ScopedTestBase
     {
         [Fact]
         public void Should_Set_Childs_Parent_To_Itself_Standalone()

tests/Avalonia.Controls.UnitTests/Presenters/ContentPresenterTests_Unrooted.cs

@@ -9,7 +9,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
     /// <summary>
     /// Tests for ContentControls that are not attached to a logical tree.
     /// </summary>
-    public class ContentPresenterTests_Unrooted
+    public class ContentPresenterTests_Unrooted : ScopedTestBase
     {
         [Fact]
         public void Setting_Content_To_Control_Should_Not_Set_Child_Unless_UpdateChild_Called()

tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests.cs

@@ -13,7 +13,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Presenters
 {
-    public class ItemsPresenterTests
+    public class ItemsPresenterTests : ScopedTestBase
     {
         [Fact]
         public void Should_Register_With_Host_When_TemplatedParent_Set()
@@ -37,7 +37,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             Assert.Equal(target.Panel, child);
         }
 
-        public class NonVirtualizingPanel
+        public class NonVirtualizingPanel : ScopedTestBase
         {
             [Fact]
             public void Creates_Containers_For_Initial_Items()

tests/Avalonia.Controls.UnitTests/Presenters/ScrollContentPresenterTests.cs

@@ -9,7 +9,7 @@ using Xunit.Sdk;
 
 namespace Avalonia.Controls.UnitTests.Presenters
 {
-    public class ScrollContentPresenterTests
+    public class ScrollContentPresenterTests : NameScopeTests
     {
         [Theory]
         [InlineData(HorizontalAlignment.Stretch, VerticalAlignment.Stretch, 10, 10, 80, 80)]

tests/Avalonia.Controls.UnitTests/Presenters/ScrollContentPresenterTests_ILogicalScrollable.cs

@@ -3,11 +3,12 @@ using System.Reactive.Linq;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ScrollContentPresenterTests_ILogicalScrollable
+    public class ScrollContentPresenterTests_ILogicalScrollable : ScopedTestBase
     {
         [Fact]
         public void Measure_Should_Pass_Unchanged_Bounds_To_ILogicalScrollable()

tests/Avalonia.Controls.UnitTests/Presenters/TextPresenter_Tests.cs

@@ -6,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Presenters
 {
-    public class TextPresenter_Tests
+    public class TextPresenter_Tests : ScopedTestBase
     {
         [Fact]
         public void TextPresenter_Can_Contain_Null_With_Password_Char_Set()

tests/Avalonia.Controls.UnitTests/Primitives/PopupRootTests.cs

@@ -15,7 +15,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class PopupRootTests
+    public class PopupRootTests : ScopedTestBase
     {
         [Fact]
         public void PopupRoot_IsAttachedToLogicalTree_Is_True()

tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs

@@ -23,7 +23,7 @@ using Avalonia.Media;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class PopupTests
+    public class PopupTests : ScopedTestBase
     {
         protected bool UsePopupHost;
 

tests/Avalonia.Controls.UnitTests/Primitives/RangeBaseTests.cs

@@ -12,7 +12,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class RangeBaseTests
+    public class RangeBaseTests : ScopedTestBase
     {
         [Fact]
         public void Maximum_Should_Be_Coerced_To_Minimum()

tests/Avalonia.Controls.UnitTests/Primitives/ScrollBarTests.cs

@@ -4,11 +4,12 @@ using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Input;
 using Avalonia.Media;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class ScrollBarTests
+    public class ScrollBarTests : ScopedTestBase
     {
         [Fact]
         public void Setting_Value_Should_Update_Track_Value()

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs

@@ -1844,27 +1844,29 @@ namespace Avalonia.Controls.UnitTests.Primitives
         }
 
         [Fact(Timeout = 2000)]
-        public async Task MoveSelection_Wrap_Does_Not_Hang_With_No_Focusable_Controls()
-        {
-            // Issue #3094.
-            var target = new TestSelector
-            {
-                Template = Template(),
-                Items =
-                {
-                    new ListBoxItem { Focusable = false },
-                    new ListBoxItem { Focusable = false },
-                },
-                SelectedIndex = 0,
-            };
-
-            target.Measure(new Size(100, 100));
-            target.Arrange(new Rect(0, 0, 100, 100));
-
+        public Task MoveSelection_Wrap_Does_Not_Hang_With_No_Focusable_Controls() =>
             // Timeout in xUnit doesn't work with synchronous methods so we need to apply hack below.
             // https://github.com/xunit/xunit/issues/2222
-            await Task.Run(() => target.MoveSelection(NavigationDirection.Next, true));
-        }
+            ThreadRunHelper.RunOnDedicatedThread(() =>
+            {
+                using var _ = UnitTestApplication.Start();
+                // Issue #3094.
+                var target = new TestSelector
+                {
+                    Template = Template(),
+                    Items =
+                    {
+                        new ListBoxItem { Focusable = false },
+                        new ListBoxItem { Focusable = false },
+                    },
+                    SelectedIndex = 0,
+                };
+
+                target.Measure(new Size(100, 100));
+                target.Arrange(new Rect(0, 0, 100, 100));
+                
+                target.MoveSelection(NavigationDirection.Next, true);
+            });
 
         [Fact]
         public void MoveSelection_Skips_Non_Focusable_Controls_When_Moving_To_Last_Item()
@@ -1907,50 +1909,54 @@ namespace Avalonia.Controls.UnitTests.Primitives
         }
 
         [Fact(Timeout = 2000)]
-        public async Task MoveSelection_Does_Not_Hang_When_All_Items_Are_Non_Focusable_And_We_Move_To_First_Item()
-        {
-            var target = new TestSelector
-            {
-                Template = Template(),
-                Items =
-                {
-                    new ListBoxItem { Focusable = false },
-                    new ListBoxItem { Focusable = false },
-                }
-            };
-
-            target.Measure(new Size(100, 100));
-            target.Arrange(new Rect(0, 0, 100, 100));
-
+        public Task MoveSelection_Does_Not_Hang_When_All_Items_Are_Non_Focusable_And_We_Move_To_First_Item() =>
             // Timeout in xUnit doesn't work with synchronous methods so we need to apply hack below.
             // https://github.com/xunit/xunit/issues/2222
-            await Task.Run(() => target.MoveSelection(NavigationDirection.First, true));
+            ThreadRunHelper.RunOnDedicatedThread(
+                () =>
+                {
+                    using var _ = UnitTestApplication.Start();
+                    var target = new TestSelector
+                    {
+                        Template = Template(),
+                        Items =
+                        {
+                            new ListBoxItem { Focusable = false },
+                            new ListBoxItem { Focusable = false },
+                        }
+                    };
 
-            Assert.Equal(-1, target.SelectedIndex);
-        }
+                    target.Measure(new Size(100, 100));
+                    target.Arrange(new Rect(0, 0, 100, 100));
+                    
+                    target.MoveSelection(NavigationDirection.First, true);
+
+                    Assert.Equal(-1, target.SelectedIndex);
+                });
 
         [Fact(Timeout = 2000)]
-        public async Task MoveSelection_Does_Not_Hang_When_All_Items_Are_Non_Focusable_And_We_Move_To_Last_Item()
-        {
-            var target = new TestSelector
-            {
-                Template = Template(),
-                Items =
-                {
-                    new ListBoxItem { Focusable = false },
-                    new ListBoxItem { Focusable = false },
-                }
-            };
-
-            target.Measure(new Size(100, 100));
-            target.Arrange(new Rect(0, 0, 100, 100));
-
+        public Task MoveSelection_Does_Not_Hang_When_All_Items_Are_Non_Focusable_And_We_Move_To_Last_Item()
             // Timeout in xUnit doesn't work with synchronous methods so we need to apply hack below.
             // https://github.com/xunit/xunit/issues/2222
-            await Task.Run(() => target.MoveSelection(NavigationDirection.Last, true));
+            => ThreadRunHelper.RunOnDedicatedThread(() =>
+            {
+                var target = new TestSelector
+                {
+                    Template = Template(),
+                    Items =
+                    {
+                        new ListBoxItem { Focusable = false },
+                        new ListBoxItem { Focusable = false },
+                    }
+                };
 
-            Assert.Equal(-1, target.SelectedIndex);
-        }
+                target.Measure(new Size(100, 100));
+                target.Arrange(new Rect(0, 0, 100, 100));
+                
+                target.MoveSelection(NavigationDirection.Last, true);
+
+                Assert.Equal(-1, target.SelectedIndex);
+            });
 
         [Fact]
         public void MoveSelection_Does_Select_Disabled_Controls()
@@ -2247,9 +2253,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Setting_IsTextSearchEnabled_Enables_Or_Disables_Text_Search()
         {
-            var pti = Mock.Of<IDispatcherImpl>(x => x.CurrentThreadIsLoopThread == true);
-            
-            using (UnitTestApplication.Start(TestServices.StyledWindow.With(dispatcherImpl: pti)))
+            using (UnitTestApplication.Start(TestServices.StyledWindow.With()))
             {
                 var items = new[]
                 {

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_AutoSelect.cs

@@ -9,7 +9,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class SelectingItemsControlTests_AutoSelect
+    public class SelectingItemsControlTests_AutoSelect : ScopedTestBase
     {
         [Fact]
         public void First_Item_Should_Be_Selected()

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs

@@ -22,7 +22,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class SelectingItemsControlTests_Multiple
+    public class SelectingItemsControlTests_Multiple : ScopedTestBase
     {
         [Fact]
         public void Setting_SelectedIndex_Should_Add_To_SelectedItems()

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_SelectedValue.cs

@@ -13,7 +13,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class SelectingItemsControlTests_SelectedValue
+    public class SelectingItemsControlTests_SelectedValue : ScopedTestBase
     {
         [Fact]
         public void Setting_SelectedItem_Sets_SelectedValue()

tests/Avalonia.Controls.UnitTests/Primitives/TabStripTests.cs

@@ -5,11 +5,12 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.LogicalTree;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class TabStripTests
+    public class TabStripTests : ScopedTestBase
     {
         [Fact]
         public void First_Tab_Should_Be_Selected_By_Default()

tests/Avalonia.Controls.UnitTests/Primitives/TemplatedControlTests.cs

@@ -14,7 +14,7 @@ using Avalonia.Media;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class TemplatedControlTests
+    public class TemplatedControlTests : ScopedTestBase
     {
         [Fact]
         public void Template_Doesnt_Get_Executed_On_Set()

tests/Avalonia.Controls.UnitTests/Primitives/ToggleButtonTests.cs

@@ -6,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Controls.Primitives.UnitTests
 {
-    public class ToggleButtonTests
+    public class ToggleButtonTests : ScopedTestBase
     {
         private const string uncheckedClass = ":unchecked";
         private const string checkedClass = ":checked";

tests/Avalonia.Controls.UnitTests/Primitives/TrackTests.cs

@@ -1,11 +1,12 @@
 using Avalonia.Controls.Primitives;
 using Avalonia.Layout;
 using Avalonia.LogicalTree;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class TrackTests
+    public class TrackTests : ScopedTestBase
     {
         [Fact]
         public void Measure_Should_Return_Thumb_DesiredWidth_In_Vertical_Orientation()

tests/Avalonia.Controls.UnitTests/Primitives/UniformGridTests.cs

@@ -1,9 +1,10 @@
 using Avalonia.Controls.Primitives;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Primitives
 {
-    public class UniformGridTests
+    public class UniformGridTests : ScopedTestBase
     {
         [Fact]
         public void Grid_Columns_Equals_Rows_For_Auto_Columns_And_Rows()

tests/Avalonia.Controls.UnitTests/RadioButtonTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class RadioButtonTests
+    public class RadioButtonTests : ScopedTestBase
     {
         [Theory]
         [InlineData(false)]

tests/Avalonia.Controls.UnitTests/RelativePanelTests.cs

@@ -4,7 +4,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class RelativePanelTests
+    public class RelativePanelTests : ScopedTestBase
     {
         [Fact]
         public void Lays_Out_1_Child_Next_the_other()

tests/Avalonia.Controls.UnitTests/Selection/InternalSelectionModelTests.cs

@@ -4,11 +4,12 @@ using System.Collections.Generic;
 using System.Collections.Specialized;
 using Avalonia.Collections;
 using Avalonia.Controls.Selection;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Selection
 {
-    public class InternalSelectionModelTests
+    public class InternalSelectionModelTests : ScopedTestBase
     {
         [Fact]
         public void Selecting_Item_Adds_To_WritableSelectedItems()

tests/Avalonia.Controls.UnitTests/Selection/SelectionModelTests_Multiple.cs

@@ -3,15 +3,16 @@ using System.Collections.Generic;
 using System.Collections.Specialized;
 using Avalonia.Collections;
 using Avalonia.Controls.Selection;
+using Avalonia.UnitTests;
 using Xunit;
 
 #nullable enable
 
 namespace Avalonia.Controls.UnitTests.Selection
 {
-    public class SelectionModelTests_Multiple
+    public class SelectionModelTests_Multiple : ScopedTestBase
     {
-        public class No_Source
+        public class No_Source : ScopedTestBase
         {
             [Fact]
             public void Can_Select_Multiple_Items_Before_Source_Assigned()
@@ -210,7 +211,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedIndex
+        public class SelectedIndex : ScopedTestBase
         {
             [Fact]
             public void SelectedIndex_Larger_Than_Source_Clears_Selection()
@@ -301,7 +302,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedIndexes
+        public class SelectedIndexes : ScopedTestBase
         {
             [Fact]
             public void PropertyChanged_Is_Raised_When_SelectedIndex_Changes()
@@ -323,7 +324,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedItem
+        public class SelectedItem : ScopedTestBase
         {
             [Fact]
             public void PropertyChanged_Is_Raised_When_SelectedIndex_Changes()
@@ -345,7 +346,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedItems
+        public class SelectedItems : ScopedTestBase
         {
             [Fact]
             public void PropertyChanged_Is_Raised_When_SelectedIndex_Changes()
@@ -367,7 +368,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Select
+        public class Select : ScopedTestBase
         {
             [Fact]
             public void Select_Sets_SelectedIndex_If_Previously_Unset()
@@ -449,7 +450,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectRange
+        public class SelectRange : ScopedTestBase
         {
             [Fact]
             public void SelectRange_Selects_Items()
@@ -517,7 +518,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Deselect
+        public class Deselect : ScopedTestBase
         {
             [Fact]
             public void Deselect_Clears_Selected_Item()
@@ -558,7 +559,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class DeselectRange
+        public class DeselectRange : ScopedTestBase
         {
             [Fact]
             public void DeselectRange_Clears_Identical_Range()
@@ -630,7 +631,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Clear
+        public class Clear : ScopedTestBase
         {
             [Fact]
             public void Clear_Raises_SelectionChanged()
@@ -656,7 +657,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class AnchorIndex
+        public class AnchorIndex : ScopedTestBase
         {
             [Fact]
             public void Setting_SelectedIndex_Sets_AnchorIndex()
@@ -768,7 +769,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SingleSelect
+        public class SingleSelect : ScopedTestBase
         {
             [Fact]
             public void Converting_To_Single_Selection_Removes_Multiple_Selection()
@@ -816,7 +817,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class CollectionChanges
+        public class CollectionChanges : ScopedTestBase
         {
             [Fact]
             public void Adding_Item_Before_Selected_Item_Updates_Indexes()
@@ -1377,7 +1378,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class BatchUpdate
+        public class BatchUpdate : ScopedTestBase
         {
             [Fact]
             public void Correctly_Batches_Selects()
@@ -1584,7 +1585,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class LostSelection
+        public class LostSelection : ScopedTestBase
         {
             [Fact]
             public void LostSelection_Called_On_Clear()
@@ -1644,7 +1645,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SourceReset
+        public class SourceReset : ScopedTestBase
         {
             [Fact]
             public void Can_Restore_Selection_In_SourceReset_Event()

tests/Avalonia.Controls.UnitTests/Selection/SelectionModelTests_Single.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls.Selection;
 using Avalonia.Controls.Utils;
+using Avalonia.UnitTests;
 using Xunit;
 using CollectionChangedEventManager = Avalonia.Controls.Utils.CollectionChangedEventManager;
 
@@ -14,7 +15,7 @@ namespace Avalonia.Controls.UnitTests.Selection
 {
     public class SelectionModelTests_Single
     {
-        public class Source
+        public class Source : ScopedTestBase
         {
             [Fact]
             public void Can_Select_Index_Before_Source_Assigned()
@@ -324,7 +325,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedIndex
+        public class SelectedIndex : ScopedTestBase
         {
             [Fact]
             public void SelectedIndex_Larger_Than_Source_Clears_Selection()
@@ -454,7 +455,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedItem
+        public class SelectedItem : ScopedTestBase
         {
             [Fact]
             public void Setting_SelectedItem_To_Valid_Item_Updates_Selection()
@@ -496,7 +497,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedIndexes
+        public class SelectedIndexes : ScopedTestBase
         {
             [Fact]
             public void PropertyChanged_Is_Raised_When_SelectedIndex_Changes()
@@ -538,7 +539,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectedItems
+        public class SelectedItems : ScopedTestBase
         {
             [Fact]
             public void PropertyChanged_Is_Raised_When_SelectedIndex_Changes()
@@ -580,7 +581,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Select
+        public class Select : ScopedTestBase
         {
             [Fact]
             public void Select_Sets_SelectedIndex()
@@ -664,7 +665,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SelectRange
+        public class SelectRange : ScopedTestBase
         {
             [Fact]
             public void SelectRange_Throws()
@@ -675,7 +676,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Deselect
+        public class Deselect : ScopedTestBase
         {
             [Fact]
             public void Deselect_Clears_Current_Selection()
@@ -721,7 +722,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class DeselectRange
+        public class DeselectRange : ScopedTestBase
         {
             [Fact]
             public void DeselectRange_Clears_Current_Selection_For_Intersecting_Range()
@@ -767,7 +768,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class Clear
+        public class Clear : ScopedTestBase
         {
             [Fact]
             public void Clear_Raises_SelectionChanged()
@@ -792,7 +793,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class AnchorIndex
+        public class AnchorIndex : ScopedTestBase
         {
             [Fact]
             public void Setting_SelectedIndex_Sets_AnchorIndex()
@@ -898,7 +899,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class SingleSelect
+        public class SingleSelect : ScopedTestBase
         {
             [Fact]
             public void Converting_To_Multiple_Selection_Preserves_Selection()
@@ -939,7 +940,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class CollectionChanges
+        public class CollectionChanges : ScopedTestBase
         {
             [Fact]
             public void Adding_Item_Before_Selected_Item_Updates_Indexes()
@@ -1273,7 +1274,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class BatchUpdate
+        public class BatchUpdate : ScopedTestBase
         {
             [Fact]
             public void Changes_Do_Not_Take_Effect_Until_EndUpdate_Called()
@@ -1309,7 +1310,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class LostSelection
+        public class LostSelection : ScopedTestBase
         {
             [Fact]
             public void LostSelection_Called_On_Clear()
@@ -1421,7 +1422,7 @@ namespace Avalonia.Controls.UnitTests.Selection
             }
         }
 
-        public class UntypedInterface
+        public class UntypedInterface : ScopedTestBase
         {
             [Fact]
             public void Raises_Untyped_SelectionChanged_Event()

tests/Avalonia.Controls.UnitTests/Shapes/EllipseTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Shapes
 {
-    public class EllipseTests
+    public class EllipseTests : ScopedTestBase
     {
         [Fact]
         public void Measure_Does_Not_Set_RenderedGeometry_Rect()

tests/Avalonia.Controls.UnitTests/Shapes/PathTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Shapes
 {
-    public class PathTests
+    public class PathTests : ScopedTestBase
     {
         [Fact]
         public void Path_With_Null_Data_Does_Not_Throw_On_Measure()

tests/Avalonia.Controls.UnitTests/Shapes/PolygonTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Shapes;
 
-public class PolygonTests
+public class PolygonTests : ScopedTestBase
 {
     [Fact]
     public void Polygon_Will_Update_Geometry_On_Shapes_Collection_Content_Change()

tests/Avalonia.Controls.UnitTests/Shapes/PolylineTests.cs

@@ -5,7 +5,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Shapes;
 
-public class PolylineTests
+public class PolylineTests : ScopedTestBase
 {
     [Fact]
     public void Polyline_Will_Update_Geometry_On_Shapes_Collection_Content_Change()

tests/Avalonia.Controls.UnitTests/Shapes/RectangleTests.cs

@@ -6,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Shapes
 {
-    public class RectangleTests
+    public class RectangleTests : ScopedTestBase
     {
         [Fact]
         public void Measure_Does_Not_Set_RenderedGeometry_Rect()

tests/Avalonia.Controls.UnitTests/SliderTests.cs

@@ -2,11 +2,12 @@
 using System.Collections.Generic;
 using System.Text;
 using Avalonia.Layout;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class SliderTests
+    public class SliderTests : ScopedTestBase
     {
         [Fact]
         public void Default_Orientation_Should_Be_Horizontal()

tests/Avalonia.Controls.UnitTests/SplitViewTests.cs

@@ -7,7 +7,7 @@ using Xunit;
 namespace Avalonia.Controls.UnitTests
 {
     
-    public class SplitViewTests
+    public class SplitViewTests : ScopedTestBase
     {
         [Fact]
         public void SplitView_PaneOpening_Should_Fire_Before_PaneOpened()

tests/Avalonia.Controls.UnitTests/StackPanelTests.cs

@@ -1,10 +1,11 @@
 using System.Linq;
 using Avalonia.Layout;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class StackPanelTests
+    public class StackPanelTests : ScopedTestBase
     {
         [Fact]
         public void Lays_Out_Children_Vertically()

tests/Avalonia.Controls.UnitTests/TabControlTests.cs

@@ -21,7 +21,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TabControlTests
+    public class TabControlTests : ScopedTestBase
     {
         static TabControlTests()
         {

tests/Avalonia.Controls.UnitTests/Templates/TemplateExtensionsTests.cs

@@ -1,10 +1,11 @@
 using System.Linq;
 using Avalonia.Controls.UnitTests;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.Templates.UnitTests
 {
-    public class TemplateExtensionsTests
+    public class TemplateExtensionsTests : ScopedTestBase
     {
         /// <summary>
         /// Control templates can themselves contain templated controls. Make sure that

tests/Avalonia.Controls.UnitTests/TextBlockTests.cs

@@ -10,7 +10,7 @@ using static System.Net.Mime.MediaTypeNames;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TextBlockTests
+    public class TextBlockTests : ScopedTestBase
     {
         [Fact]
         public void DefaultBindingMode_Should_Be_OneWay()

tests/Avalonia.Controls.UnitTests/TextBoxTests.cs

@@ -22,7 +22,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TextBoxTests
+    public class TextBoxTests : ScopedTestBase
     {
         [Fact]
         public void Opening_Context_Menu_Does_not_Lose_Selection()

tests/Avalonia.Controls.UnitTests/TextBoxTests_DataValidation.cs

@@ -18,7 +18,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TextBoxTests_DataValidation
+    public class TextBoxTests_DataValidation : ScopedTestBase
     {
         [Fact]
         public void Setter_Exceptions_Should_Set_Error_Pseudoclass()

tests/Avalonia.Controls.UnitTests/TimePickerTests.cs

@@ -15,7 +15,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TimePickerTests
+    public class TimePickerTests : ScopedTestBase
     {
         [Fact]
         public void SelectedTimeChanged_Should_Fire_When_SelectedTime_Set()

tests/Avalonia.Controls.UnitTests/ToolTipTests.cs

@@ -63,7 +63,7 @@ namespace Avalonia.Controls.UnitTests
         }
     }
 
-    public abstract class ToolTipTests
+    public abstract class ToolTipTests : ScopedTestBase
     {
         protected abstract TestServices ConfigureServices(TestServices baseServices);
 

tests/Avalonia.Controls.UnitTests/TopLevelTests.cs

@@ -17,7 +17,7 @@ using static Avalonia.Controls.UnitTests.MaskedTextBoxTests;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TopLevelTests
+    public class TopLevelTests : ScopedTestBase
     {
         [Fact]
         public void IsAttachedToLogicalTree_Is_True()

tests/Avalonia.Controls.UnitTests/TransitioningContentControlTests.cs

@@ -16,7 +16,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class TransitioningContentControlTests
+    public class TransitioningContentControlTests : ScopedTestBase
     {
         [Fact]
         public void Transition_Should_Not_Be_Run_When_First_Shown()

tests/Avalonia.Controls.UnitTests/UserControlTests.cs

@@ -8,7 +8,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class UserControlTests
+    public class UserControlTests : ScopedTestBase
     {
         [Fact]
         public void Should_Be_Styled_As_UserControl()

tests/Avalonia.Controls.UnitTests/Utils/AncestorFinderTests.cs

@@ -4,12 +4,13 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Avalonia.Controls.Utils;
+using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Utils
 {
-    public class AncestorFinderTests
+    public class AncestorFinderTests : ScopedTestBase
     {
         [Fact]
         public void SanityCheck()

tests/Avalonia.Controls.UnitTests/Utils/CollectionChangedEventManagerTests.cs

@@ -4,12 +4,13 @@ using System.Collections.Specialized;
 using System.Text;
 using Avalonia.Collections;
 using Avalonia.Controls.Utils;
+using Avalonia.UnitTests;
 using Xunit;
 using CollectionChangedEventManager = Avalonia.Controls.Utils.CollectionChangedEventManager;
 
 namespace Avalonia.Controls.UnitTests.Utils
 {
-    public class CollectionChangedEventManagerTests
+    public class CollectionChangedEventManagerTests : ScopedTestBase
     {
         [Fact]
         public void AddListener_Listens_To_Events()

tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs

@@ -10,7 +10,7 @@ using Factory = System.Func<int, System.Action<object>, Avalonia.Controls.Window
 
 namespace Avalonia.Controls.UnitTests.Utils
 {
-    public class HotKeyManagerTests
+    public class HotKeyManagerTests : ScopedTestBase
     {
         [Fact]
         public void HotKeyManager_Should_Register_And_Unregister_Key_Binding()

tests/Avalonia.Controls.UnitTests/Utils/SafeEnumerableHashSetTests.cs

@@ -1,10 +1,11 @@
 using System.Collections.Generic;
+using Avalonia.UnitTests;
 using Avalonia.Utilities;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests.Utils
 {
-    public class SafeEnumerableHashSetTests
+    public class SafeEnumerableHashSetTests : ScopedTestBase
     {
         [Fact]
         public void Set_Is_Not_Copied_Outside_Enumeration()

tests/Avalonia.Controls.UnitTests/ViewboxTests.cs

@@ -7,7 +7,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class ViewboxTests
+    public class ViewboxTests : ScopedTestBase
     {
         [Fact]
         public void Viewbox_Stretch_Uniform_Child()

tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs

@@ -10,6 +10,7 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Layout;
+using Avalonia.Threading;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Moq;
@@ -19,7 +20,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class VirtualizingCarouselPanelTests
+    public class VirtualizingCarouselPanelTests : ScopedTestBase
     {
         [Fact]
         public void Initial_Item_Is_Displayed()
@@ -134,7 +135,7 @@ namespace Avalonia.Controls.UnitTests
             });
         }
 
-        public class Transitions
+        public class Transitions : ScopedTestBase
         {
             [Fact]
             public void Initial_Item_Does_Not_Start_Transition()
@@ -175,49 +176,59 @@ namespace Avalonia.Controls.UnitTests
             public void Changing_SelectedIndex_transitions_forward_cycle()
             {
                 using var app = Start();
-                var items = new Control[] { new Button(), new Canvas(), new Label() };
-                var transition = new Mock<IPageTransition>();
-                var (target, carousel) = CreateTarget(items, transition.Object);
-                var cycleindexes = new[] { 1, 2, 0};
-
-                for (int cycleIndex = 0; cycleIndex < cycleindexes.Length; cycleIndex++)
+                Dispatcher.UIThread.Invoke(() => // This sets up a proper sync context
                 {
-                    carousel.SelectedIndex = cycleindexes[cycleIndex];
-                    Layout(target);
+                    var items = new Control[] { new Button(), new Canvas(), new Label() };
+                    var transition = new Mock<IPageTransition>();
+                    var (target, carousel) = CreateTarget(items, transition.Object);
+                    var cycleindexes = new[] { 1, 2, 0 };
 
-                    var index = cycleIndex;
-                    transition.Verify(x => x.Start(
-                            index > 0 ? items[cycleindexes[index - 1]] : items[0],
-                            items[cycleindexes[index]],
-                            true,
-                            It.IsAny<CancellationToken>()),
-                        Times.Once);
-                }
+                    for (int cycleIndex = 0; cycleIndex < cycleindexes.Length; cycleIndex++)
+                    {
+                        carousel.SelectedIndex = cycleindexes[cycleIndex];
+                        Layout(target);
+                        
+                        Dispatcher.UIThread.RunJobs();
+
+                        var index = cycleIndex;
+                        transition.Verify(x => x.Start(
+                                index > 0 ? items[cycleindexes[index - 1]] : items[0],
+                                items[cycleindexes[index]],
+                                true,
+                                It.IsAny<CancellationToken>()),
+                            Times.Once);
+                    }
+                });
             }
 
             [Fact]
             public void Changing_SelectedIndex_transitions_backward_cycle()
             {
                 using var app = Start();
-                var items = new Control[] { new Button(), new Canvas(), new Label() };
-                var transition = new Mock<IPageTransition>();
-                var (target, carousel) = CreateTarget(items, transition.Object);
-
-                var cycleindexes = new[] { 2, 1, 0};
-
-                for (int cycleIndex = 0; cycleIndex < cycleindexes.Length; cycleIndex++)
+                Dispatcher.UIThread.Invoke(() => // This sets up a proper sync context
                 {
-                    carousel.SelectedIndex = cycleindexes[cycleIndex];
-                    Layout(target);
+                    var items = new Control[] { new Button(), new Canvas(), new Label() };
+                    var transition = new Mock<IPageTransition>();
+                    var (target, carousel) = CreateTarget(items, transition.Object);
 
-                    var index = cycleIndex;
-                    transition.Verify(x => x.Start(
-                            index > 0 ? items[cycleindexes[index - 1]] : items[0],
-                            items[cycleindexes[index]],
-                            false,
-                            It.IsAny<CancellationToken>()),
-                        Times.Once);
-                }
+                    var cycleindexes = new[] { 2, 1, 0 };
+
+                    for (int cycleIndex = 0; cycleIndex < cycleindexes.Length; cycleIndex++)
+                    {
+                        carousel.SelectedIndex = cycleindexes[cycleIndex];
+                        Layout(target);
+
+                        Dispatcher.UIThread.RunJobs();
+                        
+                        var index = cycleIndex;
+                        transition.Verify(x => x.Start(
+                                index > 0 ? items[cycleindexes[index - 1]] : items[0],
+                                items[cycleindexes[index]],
+                                false,
+                                It.IsAny<CancellationToken>()),
+                            Times.Once);
+                    }
+                });
             }
 
             [Fact]

tests/Avalonia.Controls.UnitTests/WindowBaseTests.cs

@@ -17,7 +17,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class WindowBaseTests
+    public class WindowBaseTests : ScopedTestBase
     {
         [Fact]
         public void Activate_Should_Call_Impl_Activate()

tests/Avalonia.Controls.UnitTests/WindowTests.cs

@@ -12,7 +12,7 @@ using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class WindowTests
+    public class WindowTests : ScopedTestBase
     {
         [Fact]
         public void Setting_Title_Should_Set_Impl_Title()
@@ -672,7 +672,7 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        public class SizingTests
+        public class SizingTests : ScopedTestBase
         {
             [Fact]
             public void Child_Should_Be_Measured_With_Width_And_Height_If_SizeToContent_Is_Manual()

tests/Avalonia.Controls.UnitTests/WrapPanelTests.cs

@@ -1,10 +1,11 @@
 using System;
 using Avalonia.Layout;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Controls.UnitTests
 {
-    public class WrapPanelTests
+    public class WrapPanelTests : ScopedTestBase
     {
         [Fact]
         public void Lays_Out_Horizontally_On_Separate_Lines()

tests/Avalonia.LeakTests/AvaloniaObjectTests.cs

@@ -11,6 +11,7 @@ using Avalonia.Data.Core;
 using Avalonia.Markup.Xaml.MarkupExtensions;
 using Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings;
 using Avalonia.Threading;
+using Avalonia.UnitTests;
 using JetBrains.dotMemoryUnit;
 using Xunit;
 using Xunit.Abstractions;
@@ -18,7 +19,7 @@ using Xunit.Abstractions;
 namespace Avalonia.LeakTests
 {
     [DotMemoryUnit(FailIfRunWithoutSupport = false)]
-    public class AvaloniaObjectTests
+    public class AvaloniaObjectTests : ScopedTestBase
     {
         public AvaloniaObjectTests(ITestOutputHelper atr)
         {
@@ -159,7 +160,7 @@ namespace Avalonia.LeakTests
             }
 
             var weakTarget = SetupBinding();
-
+            
             CollectGarbage();
             Assert.False(weakTarget.IsAlive);
         }

tests/Avalonia.Markup.UnitTests/Avalonia.Markup.UnitTests.csproj

@@ -16,8 +16,7 @@
     <ProjectReference Include="..\..\src\Avalonia.Base\Avalonia.Base.csproj" />
     <ProjectReference Include="..\..\src\Avalonia.Controls\Avalonia.Controls.csproj" />
     <ProjectReference Include="..\Avalonia.UnitTests\Avalonia.UnitTests.csproj" />
-  </ItemGroup>
-  <ItemGroup>
+    <Compile Include="../Shared/ScopedSanityCheck.cs"/>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
 </Project>

tests/Avalonia.Markup.UnitTests/Data/BindingTests.cs

@@ -7,12 +7,13 @@ using Avalonia.Controls;
 using Avalonia.Data;
 using Avalonia.Data.Converters;
 using Avalonia.Threading;
+using Avalonia.UnitTests;
 using Moq;
 using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data
 {
-    public class BindingTests
+    public class BindingTests : ScopedTestBase
     {
         [Fact]
         public void OneWay_Binding_Should_Be_Set_Up()

tests/Avalonia.Markup.UnitTests/Data/BindingTests_Converters.cs

@@ -4,12 +4,13 @@ using Avalonia.Controls;
 using Avalonia.Data;
 using Avalonia.Data.Converters;
 using Avalonia.Data.Core;
+using Avalonia.UnitTests;
 using Moq;
 using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data
 {
-    public class BindingTests_Converters
+    public class BindingTests_Converters : ScopedTestBase
     {
         [Fact]
         public void Converter_Should_Be_Used()

tests/Avalonia.Markup.UnitTests/Data/BindingTests_DataValidation.cs

@@ -13,7 +13,7 @@ namespace Avalonia.Markup.UnitTests.Data
 {
     public class BindingTests_DataValidation
     {
-        public abstract class TestBase<T>
+        public abstract class TestBase<T> : ScopedTestBase
             where T : AvaloniaProperty<int>
         {
             [Fact]

tests/Avalonia.Markup.UnitTests/Data/BindingTests_Delay.cs

@@ -10,7 +10,7 @@ using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data;
 
-public class BindingTests_Delay : IDisposable
+public class BindingTests_Delay : ScopedTestBase, IDisposable
 {
     private const int DelayMilliseconds = 10;
     private const string InitialFooValue = "foo";
@@ -39,6 +39,7 @@ public class BindingTests_Delay : IDisposable
     public void Dispose()
     {
         _app.Dispose();
+        base.Dispose();
     }
 
     [Fact]

tests/Avalonia.Markup.UnitTests/Data/BindingTests_ElementName.cs

@@ -7,7 +7,7 @@ using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data
 {
-    public class BindingTests_ElementName
+    public class BindingTests_ElementName : ScopedTestBase
     {
         [Fact]
         public void Should_Bind_To_Element_Path()

tests/Avalonia.Markup.UnitTests/Data/BindingTests_Logging.cs

@@ -20,9 +20,9 @@ using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data
 {
-    public class BindingTests_Logging
+    public class BindingTests_Logging : ScopedTestBase
     {
-        public class DataContext
+        public class DataContext : ScopedTestBase
         {
             [Fact]
             public void Should_Not_Log_Missing_Member_On_Null_DataContext()
@@ -68,7 +68,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class Source
+        public class Source : ScopedTestBase
         {
             [Fact]
             public void Should_Log_Null_Source()
@@ -96,7 +96,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class LogicalAncestor
+        public class LogicalAncestor : ScopedTestBase
         {
             [Fact]
             public void Should_Log_Ancestor_Not_Found()
@@ -124,7 +124,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class VisualAncestor
+        public class VisualAncestor : ScopedTestBase
         {
             [Fact]
             public void Should_Log_Ancestor_Not_Found()
@@ -187,7 +187,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class NamedElement
+        public class NamedElement : ScopedTestBase
         {
             [Fact]
             public void Should_Log_NameScope_Not_Found()
@@ -233,7 +233,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class Converter
+        public class Converter : ScopedTestBase
         {
             [Fact]
             public void Should_Log_Error_For_Unconvertible_Type()
@@ -275,7 +275,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class Fallback
+        public class Fallback : ScopedTestBase
         {
             [Theory]
             [InlineData(true)]
@@ -324,7 +324,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class NonControlDataContext
+        public class NonControlDataContext : ScopedTestBase
         {
             [Fact]
             public void Should_Not_Log_Missing_Member_On_Null_DataContext()
@@ -369,7 +369,7 @@ namespace Avalonia.Markup.UnitTests.Data
             }
         }
 
-        public class CompiledBinding
+        public class CompiledBinding : ScopedTestBase
         {
             [Fact]
             public void Should_Log_For_Invalid_DataContext_Type()

tests/Avalonia.Markup.UnitTests/Data/BindingTests_Method.cs

@@ -2,11 +2,12 @@
 using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Avalonia.UnitTests;
 using Xunit;
 
 namespace Avalonia.Markup.UnitTests.Data
 {
-    public class BindingTests_Method
+    public class BindingTests_Method : ScopedTestBase
     {
         [Fact]
         public void Binding_To_Private_Methods_Shouldnt_Work()