Fix common warnings (#20311)

.editorconfig

@@ -141,9 +141,6 @@ dotnet_analyzer_diagnostic.category-Performance.severity = none #error - Uncomme
 # CS0649: Field 'field' is never assigned to, and will always have its default value 'value'
 dotnet_diagnostic.CS0649.severity = error
 
-# CS1591: Missing XML comment for publicly visible type or member
-dotnet_diagnostic.CS1591.severity = suggestion
-
 # CS0162: Remove unreachable code
 dotnet_diagnostic.CS0162.severity = error
 # CA1018: Mark attributes with AttributeUsageAttribute

samples/Directory.Build.props

@@ -4,6 +4,7 @@
     <IsPackable>false</IsPackable>
     <AvaloniaPreviewerNetCoreToolPath>$(MSBuildThisFileDirectory)..\src\tools\Avalonia.Designer.HostApp\bin\Debug\$(AvsCurrentTargetFramework)\Avalonia.Designer.HostApp.dll</AvaloniaPreviewerNetCoreToolPath>
     <EnableNETAnalyzers>false</EnableNETAnalyzers>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
     <LangVersion>14.0</LangVersion>
     <NoWarn>$(NoWarn);CS8002</NoWarn> <!-- ignore signing warnings for samples -->
   </PropertyGroup>

samples/GpuInterop/GpuInterop.csproj

@@ -5,9 +5,14 @@
     <TargetFramework>$(AvsCurrentTargetFramework)</TargetFramework>
     <TargetLatestRuntimePatch>true</TargetLatestRuntimePatch>
     <Nullable>enable</Nullable>
-    <GenerateDocumentationFile>false</GenerateDocumentationFile>
     <UseD3DCompiler>true</UseD3DCompiler>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+
+    <!--
+      Reference to System.Text.Json is explicitly added to avoid a deprecated version,
+      we don't care about it not being pruned.
+    -->
+    <NoWarn>$(NoWarn);NU1510</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

samples/MiniMvvm/MiniCommand.cs

@@ -58,10 +58,10 @@ namespace MiniMvvm
     {
         public static MiniCommand Create(Action cb) => new MiniCommand<object>(_ => cb());
         public static MiniCommand Create<TArg>(Action<TArg> cb) => new MiniCommand<TArg>(cb);
-        public static MiniCommand CreateFromTask(Func<Task> cb) => new MiniCommand<object>(_ => cb());
+        public static MiniCommand CreateFromTask(Func<Task> cb) => new MiniCommand<object?>(_ => cb());
         
-        public abstract bool CanExecute(object parameter);
-        public abstract void Execute(object parameter);
-        public abstract event EventHandler CanExecuteChanged;
+        public abstract bool CanExecute(object? parameter);
+        public abstract void Execute(object? parameter);
+        public abstract event EventHandler? CanExecuteChanged;
     }
 }

samples/MiniMvvm/PropertyChangedExtensions.cs

@@ -31,13 +31,13 @@ namespace MiniMvvm
                     _info = info;
                     _observer = observer;
                     _target.PropertyChanged += OnPropertyChanged;
-                    _observer.OnNext((T)_info.GetValue(_target));
+                    _observer.OnNext((T)_info.GetValue(_target)!);
                 }
 
-                private void OnPropertyChanged(object sender, PropertyChangedEventArgs e)
+                private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e)
                 {
                     if (e.PropertyName == _info.Name)
-                        _observer.OnNext((T)_info.GetValue(_target));
+                        _observer.OnNext((T)_info.GetValue(_target)!);
                 }
 
                 public void Dispose()

samples/TextTestApp/InteractiveLineControl.cs

@@ -233,6 +233,7 @@ namespace TextTestApp
         }
 
         private GenericTextRunProperties? _textRunProperties;
+
         public GenericTextRunProperties TextRunProperties
         {
             get
@@ -241,9 +242,6 @@ namespace TextTestApp
             }
             set
             {
-                if (value == null)
-                    throw new ArgumentNullException(nameof(value));
-
                 _textRunProperties = value;
                 SetCurrentValue(FontFamilyProperty, value.Typeface.FontFamily);
                 SetCurrentValue(FontFeaturesProperty, value.FontFeatures);

samples/TextTestApp/MainWindow.axaml.cs

@@ -320,11 +320,17 @@ namespace TextTestApp
 
         private void OnBufferSelectionChanged(object? sender, SelectionChangedEventArgs e)
         {
-            List<Rect> rectangles = new List<Rect>(_buffer.Selection.Count);
+            if (_selectionAdorner is null)
+                return;
 
-            foreach (var row in _buffer.SelectedItems)
-                if (row is Control { Tag: Rect rect })
-                    rectangles.Add(rect);
+            var rectangles = new List<Rect>(_buffer.Selection.Count);
+
+            if (_buffer.SelectedItems is { } selectedItems)
+            {
+                foreach (var row in selectedItems)
+                    if (row is Control { Tag: Rect rect })
+                        rectangles.Add(rect);
+            }
 
             _selectionAdorner.Rectangles = rectangles;
         }

src/Android/Avalonia.Android/Avalonia.Android.csproj

@@ -4,6 +4,9 @@
     <SupportedOSPlatformVersion>$(AvsMinSupportedAndroidVersion)</SupportedOSPlatformVersion>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <AndroidResgenNamespace>Avalonia.Android.Internal</AndroidResgenNamespace>
+
+    <!-- Xamarin.AndroidX assemblies are not signed -->
+    <NoWarn>$(NoWarn);CS8002</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\packages\Avalonia\Avalonia.csproj" />

src/Android/Avalonia.Android/ChoreographerTimer.cs

@@ -13,7 +13,6 @@ namespace Avalonia.Android
 {
     internal sealed class ChoreographerTimer : IRenderTimer
     {
-        private static readonly bool s_supports64Callback = OperatingSystem.IsAndroidVersionAtLeast(29);
         private readonly object _lock = new();
         private readonly TaskCompletionSource<IntPtr> _choreographer = new();
         private readonly AutoResetEvent _event = new(false);
@@ -126,7 +125,7 @@ namespace Avalonia.Android
         private static unsafe void PostFrameCallback(IntPtr choreographer, IntPtr data)
         {
             // AChoreographer_postFrameCallback is deprecated on 10.0+. 
-            if (s_supports64Callback)
+            if (OperatingSystem.IsAndroidVersionAtLeast(29))
             {
                 AChoreographer_postFrameCallback64(choreographer, &FrameCallback64, data);
             }

src/Android/Avalonia.Android/Platform/Storage/AndroidStorageProvider.cs

@@ -202,7 +202,7 @@ internal class AndroidStorageProvider : IStorageProvider
     public async Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
     {
         var file = await SaveFilePickerAsync(options).ConfigureAwait(false);
-        return new SaveFilePickerResult(file);
+        return new SaveFilePickerResult { File = file };
     }
 
     public async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)

src/Avalonia.Base/Controls/NameScope.cs

@@ -14,8 +14,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the NameScope attached property.
         /// </summary>
-        public static readonly AttachedProperty<INameScope> NameScopeProperty =
-            AvaloniaProperty.RegisterAttached<NameScope, StyledElement, INameScope>("NameScope");
+        public static readonly AttachedProperty<INameScope?> NameScopeProperty =
+            AvaloniaProperty.RegisterAttached<NameScope, StyledElement, INameScope?>("NameScope");
 
         /// <inheritdoc/>
         public bool IsCompleted { get; private set; }
@@ -30,7 +30,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="styled">The styled element.</param>
         /// <returns>The value of the NameScope attached property.</returns>
-        public static INameScope GetNameScope(StyledElement styled)
+        public static INameScope? GetNameScope(StyledElement styled)
         {
             _ = styled ?? throw new ArgumentNullException(nameof(styled));
 
@@ -42,7 +42,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="styled">The styled element.</param>
         /// <param name="value">The value to set.</param>
-        public static void SetNameScope(StyledElement styled, INameScope value)
+        public static void SetNameScope(StyledElement styled, INameScope? value)
         {
             _ = styled ?? throw new ArgumentNullException(nameof(styled));
 

src/Avalonia.Base/Media/PolylineGeometry.cs

@@ -44,7 +44,6 @@ namespace Avalonia.Media
             _fillRule = FillRule.EvenOdd;
         }
 
-        /// <summary>
         /// <summary>
         /// Initializes a new instance of the <see cref="PolylineGeometry"/> class.
         /// </summary>

src/Avalonia.Base/Media/TextFormatting/TextParagraphProperties.cs

@@ -53,7 +53,7 @@
         /// <remarks>
         /// If not null, text decorations to apply to all runs in the line. This is in addition
         /// to any text decorations specified by the TextRunProperties for individual text runs.
-        /// </summary>
+        /// </remarks>
         public virtual TextDecorationCollection? TextDecorations => null;
 
         /// <summary>

src/Avalonia.Base/Media/TextPathSegmentEllipsis.cs

@@ -415,12 +415,6 @@ namespace Avalonia.Media
             return false;
         }
 
-        /// <summary>
-        /// Finds the index of the text run and the offset within that run corresponding to the specified character
-        /// index.
-        /// </summary>
-        /// <remarks>If the specified character index does not fall within any run, the method returns
-
         /// <summary>
         /// Calculates the total width of a specified segment within a sequence of text runs.
         /// </summary>

src/Avalonia.Base/Platform/Storage/FilePickerOpenOptions.cs

@@ -11,8 +11,8 @@ public class FilePickerOpenOptions : PickerOptions
     /// Gets or sets the file type that should be preselected when the dialog is opened.
     /// </summary>
     /// <remarks>
-    /// This value should reference one of the items in <see cref="FileTypeChoices"/>.
-    /// If not set, the first file type in <see cref="FileTypeChoices"/> may be selected by default.
+    /// This value should reference one of the items in <see cref="FileTypeFilter"/>.
+    /// If not set, the first file type in <see cref="FileTypeFilter"/> may be selected by default.
     /// </remarks>
     public FilePickerFileType? SuggestedFileType { get; set; }
 

src/Avalonia.Base/Platform/Storage/NoopStorageProvider.cs

@@ -21,7 +21,7 @@ internal class NoopStorageProvider : BclStorageProvider
 
     public override Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
     {
-        return Task.FromResult(new SaveFilePickerResult(null));
+        return Task.FromResult(new SaveFilePickerResult());
     }
 
     public override bool CanPickFolder => false;

src/Avalonia.Base/Platform/Storage/SaveFilePickerResult.cs

@@ -3,13 +3,8 @@ namespace Avalonia.Platform.Storage;
 /// <summary>
 /// Extended result of the <see cref="IStorageProvider.SaveFilePickerWithResultAsync(FilePickerSaveOptions)"/> operation.
 /// </summary>
-public readonly struct SaveFilePickerResult
+public readonly record struct SaveFilePickerResult
 {
-    internal SaveFilePickerResult(IStorageFile? file)
-    {
-        File = file;
-    }
-
     /// <summary>
     /// Saved <see cref="IStorageFile"/> or null if user canceled the dialog.
     /// </summary>

src/Avalonia.Base/Rendering/Composition/CompositionDrawingSurface.cs

@@ -47,7 +47,9 @@ public sealed class CompositionDrawingSurface : CompositionSurface, IDisposable
     /// </summary>
     /// <param name="image">GPU image with new surface contents</param>
     /// <param name="waitForSemaphore">The semaphore to wait for before accessing the image</param>
+    /// <param name="waitForValue">The value to wait for before accessing the image</param>
     /// <param name="signalSemaphore">The semaphore to signal after accessing the image</param>
+    /// <param name="signalValue">The value to signal after accessing the image</param>
     /// <returns>A task that completes when update operation is completed and user code is free to destroy or dispose the image</returns>
     public Task UpdateWithTimelineSemaphoresAsync(ICompositionImportedGpuImage image,
         ICompositionImportedGpuSemaphore waitForSemaphore, ulong waitForValue,

src/Avalonia.Base/Styling/Selector.cs

@@ -76,7 +76,11 @@ namespace Avalonia.Styling
         /// <param name="owner">The owner style.</param>
         public abstract string ToString(Style? owner);
 
-        /// <inheritdoc cref="ToString(Style?)"/>
+        /// <summary>
+        /// Gets a string representing the selector, with the nesting separator (`^`) replaced with
+        /// the parent selector.
+        /// </summary>
+        /// <param name="owner">The owner style.</param>
         /// <param name="hasNext">Whether there is a selector that comes after this one.</param>
         internal virtual string ToString(Style? owner, bool hasNext) => ToString(owner);
 

src/Avalonia.Base/Threading/DispatcherPriorityAwaitable.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
@@ -8,6 +9,10 @@ namespace Avalonia.Threading;
 /// <summary>
 ///     A simple awaitable type that will return a DispatcherPriorityAwaiter.
 /// </summary>
+[UnconditionalSuppressMessage(
+    "Performance",
+    "CA1815:Override equals and operator equals on value types",
+    Justification = "This struct is not supposed to be used directly and should not be compared.")]
 public struct DispatcherPriorityAwaitable
 {
     private readonly Dispatcher _dispatcher;
@@ -30,6 +35,10 @@ public struct DispatcherPriorityAwaitable
 /// <remarks>
 ///     This is returned from DispatcherPriorityAwaitable.GetAwaiter()
 /// </remarks>
+[UnconditionalSuppressMessage(
+    "Performance",
+    "CA1815:Override equals and operator equals on value types",
+    Justification = "This struct is not supposed to be used directly and should not be compared.")]
 public struct DispatcherPriorityAwaiter : INotifyCompletion
 {
     private readonly Dispatcher _dispatcher;
@@ -72,6 +81,10 @@ public struct DispatcherPriorityAwaiter : INotifyCompletion
 /// <summary>
 ///     A simple awaitable type that will return a DispatcherPriorityAwaiter&lt;T&gt;.
 /// </summary>
+[UnconditionalSuppressMessage(
+    "Performance",
+    "CA1815:Override equals and operator equals on value types",
+    Justification = "This struct is not supposed to be used directly and should not be compared.")]
 public struct DispatcherPriorityAwaitable<T>
 {
     private readonly Dispatcher _dispatcher;
@@ -94,6 +107,10 @@ public struct DispatcherPriorityAwaitable<T>
 /// <remarks>
 ///     This is returned from DispatcherPriorityAwaitable&lt;T&gt;.GetAwaiter()
 /// </remarks>
+[UnconditionalSuppressMessage(
+    "Performance",
+    "CA1815:Override equals and operator equals on value types",
+    Justification = "This struct is not supposed to be used directly and should not be compared.")]
 public struct DispatcherPriorityAwaiter<T> : INotifyCompletion
 {
     private readonly Dispatcher _dispatcher;

src/Avalonia.Controls/TextBlock.cs

@@ -97,11 +97,6 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="LetterSpacing"/> property.
         /// </summary>
-        /// <remarks>
-        /// This property uses <see cref="AvaloniaProperty.AddOwner{TOwner}(AvaloniaProperty)"/> to share the same
-        /// definition as <see cref="TextElement.LetterSpacingProperty"/>, ensuring consistent behavior across text
-        /// elements and templated controls.
-        /// </remarks>
         public static readonly StyledProperty<double> LetterSpacingProperty =
             TextElement.LetterSpacingProperty.AddOwner<TextBlock>();
 

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -309,7 +309,7 @@ namespace Avalonia.DesignerSupport.Remote
 
         public override Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
         {
-            return Task.FromResult<SaveFilePickerResult>(new SaveFilePickerResult(null));
+            return Task.FromResult(new SaveFilePickerResult());
         }
 
         public override bool CanPickFolder => false;

src/Avalonia.Dialogs/ManagedStorageProvider.cs

@@ -56,7 +56,7 @@ internal class ManagedStorageProvider : BclStorageProvider
             options.FileTypeChoices[index] :
             null;
 
-        return new SaveFilePickerResult(file) { SelectedFileType = filterType };
+        return new SaveFilePickerResult { File = file, SelectedFileType = filterType };
     }
 
     public override async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)

src/Avalonia.FreeDesktop/DBusSystemDialog.cs

@@ -102,7 +102,7 @@ namespace Avalonia.FreeDesktop
         public override async Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
         {
             var (file, selectedType) = await SaveFilePickerCoreAsync(options).ConfigureAwait(false);
-            return new SaveFilePickerResult(file) { SelectedFileType = selectedType };
+            return new SaveFilePickerResult { File = file, SelectedFileType = selectedType };
         }
 
         private async Task<(IStorageFile? file, FilePickerFileType? selectedType)> SaveFilePickerCoreAsync(

src/Avalonia.Native/GpuHandleWrapFeature.cs

@@ -1,3 +1,5 @@
+#nullable enable
+
 using System;
 using Avalonia.Native.Interop;
 using Avalonia.Platform;

src/Avalonia.Native/StorageProviderImpl.cs

@@ -30,7 +30,7 @@ internal sealed class StorageProviderImpl(TopLevelImpl topLevel, StorageProvider
     public async Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
     {
         var (file, selectedType) = await native.SaveFileDialog(topLevel, options).ConfigureAwait(false);
-        return new SaveFilePickerResult(file) { SelectedFileType = selectedType };
+        return new SaveFilePickerResult { File = file, SelectedFileType = selectedType };
     }
 
     public Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)

src/Avalonia.X11/NativeDialogs/GtkNativeFileDialogs.cs

@@ -86,7 +86,7 @@ namespace Avalonia.X11.NativeDialogs
                     ? new BclStorageFile(new FileInfo(path))
                     : null;
 
-                return new SaveFilePickerResult(file) { SelectedFileType = selectedFilter };
+                return new SaveFilePickerResult { File = file, SelectedFileType = selectedFilter };
             });
         }
 

src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs

@@ -93,7 +93,7 @@ internal class BrowserStorageProvider : IStorageProvider
     public async Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
     {
         var file = await SaveFilePickerAsync(options).ConfigureAwait(false);
-        return new SaveFilePickerResult(file);
+        return new SaveFilePickerResult { File = file };
     }
 
     public async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)

src/Markup/Avalonia.Markup.Xaml.Loader/Avalonia.Markup.Xaml.Loader.csproj

@@ -11,10 +11,6 @@
     <ProjectReference Include="..\Avalonia.Markup.Xaml\Avalonia.Markup.Xaml.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Compile Include="../../Avalonia.Base/Diagnostics/TrimmingMessages.cs" Link="Diagnostics/AvaloniaTrimmingMessages.cs" />
-  </ItemGroup>
-
   <Import Project="IncludeXamlIlSre.props" />
   <Import Project="..\..\..\build\DevAnalyzers.props" />
   <Import Project="..\..\..\build\TrimmingEnable.props" />

src/Windows/Avalonia.Win32/Win32StorageProvider.cs

@@ -79,7 +79,7 @@ namespace Avalonia.Win32
                 options.FileTypeChoices[index - 1] :
                 null;
 
-            return new SaveFilePickerResult(file) { SelectedFileType = selectedFileType };
+            return new SaveFilePickerResult { File = file, SelectedFileType = selectedFileType };
         }
 
         private unsafe Task<(IReadOnlyList<TStorageItem> items, int typeIndex)> ShowFilePicker<TStorageItem>(

src/iOS/Avalonia.iOS/Storage/IOSStorageProvider.cs

@@ -232,7 +232,7 @@ internal class IOSStorageProvider : IStorageProvider
     public async Task<SaveFilePickerResult> SaveFilePickerWithResultAsync(FilePickerSaveOptions options)
     {
         var file = await SaveFilePickerAsync(options).ConfigureAwait(false);
-        return new SaveFilePickerResult(file);
+        return new SaveFilePickerResult { File = file };
     }
 
     public async Task<IReadOnlyList<IStorageFolder>> OpenFolderPickerAsync(FolderPickerOpenOptions options)

tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs

@@ -49,7 +49,7 @@ public abstract class PointerTestsBase : ScopedTestBase
         impl.DefaultValue = DefaultValue.Mock;
         impl.SetupAllProperties();
         impl.SetupGet(r => r.RenderScaling).Returns(1);
-        impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns(null);
+        impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns((object?)null);
         impl.Setup(r => r.Compositor).Returns(RendererMocks.CreateDummyCompositor());
         impl.Setup(r => r.PointToScreen(It.IsAny<Point>())).Returns<Point>(p => new PixelPoint((int)p.X, (int)p.Y));
         impl.Setup(r => r.PointToClient(It.IsAny<PixelPoint>())).Returns<PixelPoint>(p => new Point(p.X, p.Y));

tests/Avalonia.Build.Tasks.UnitTest/CompileAvaloniaXamlTaskTest.cs

@@ -14,7 +14,7 @@ public class CompileAvaloniaXamlTaskTest
     public void Does_Not_Fail_When_Codebehind_Contains_DllImport()
     {
         using var engine = UnitTestBuildEngine.Start();
-        var basePath = Path.Combine(Path.GetDirectoryName(new Uri(Assembly.GetExecutingAssembly().CodeBase).LocalPath), "Assets");
+        var basePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, "Assets");
         var assembly = new TaskItem(Path.Combine(basePath, "PInvoke.dll"));
         assembly.SetMetadata(CompileAvaloniaXamlTask.AvaloniaCompileOutputMetadataName, Path.Combine(basePath, "Avalonia", Path.GetFileName(assembly.ItemSpec)));
         var references = File.ReadAllLines(Path.Combine(basePath, "PInvoke.dll.refs")).Select(p => new TaskItem(p)).ToArray();

tests/Avalonia.Controls.UnitTests/GridSplitterTests.cs

@@ -1,3 +1,5 @@
+#nullable enable
+
 using System.Collections.Generic;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;

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

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading.Tasks;
 using Avalonia.Platform;
 using Avalonia.Threading;
@@ -102,6 +103,7 @@ public class ScreensTests : ScopedTestBase
     }
 
     [Fact]
+    [UnconditionalSuppressMessage("Usage", "xUnit1031:Do not use blocking task operations in test method", Justification = "Explicit threading test")]
     public void Should_Raise_Event_When_Screen_Changed_From_Another_Thread()
     {
         using var _ = UnitTestApplication.Start(TestServices.MockThreadingInterface);

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

@@ -1,3 +1,5 @@
+#nullable enable
+
 using Avalonia.Collections;
 using Avalonia.Controls.Shapes;
 using Avalonia.Media;
@@ -22,7 +24,7 @@ public class ShapeTests : ScopedTestBase
         });
 
         Assert.NotNull(pen);
-        Assert.Equal(10, pen!.MiterLimit);
+        Assert.Equal(10, pen.MiterLimit);
     }
 
     [Fact]
@@ -40,7 +42,7 @@ public class ShapeTests : ScopedTestBase
         var pen = RenderAndGetPen(shape);
 
         Assert.NotNull(pen);
-        Assert.Equal(2, pen!.MiterLimit);
+        Assert.Equal(2, pen.MiterLimit);
     }
 
     [Fact]
@@ -54,7 +56,7 @@ public class ShapeTests : ScopedTestBase
         });
 
         Assert.NotNull(pen);
-        Assert.Equal(6, pen!.Thickness);
+        Assert.Equal(6, pen.Thickness);
     }
 
     [Fact]
@@ -70,7 +72,7 @@ public class ShapeTests : ScopedTestBase
         });
 
         Assert.NotNull(pen);
-        Assert.Equal(PenLineCap.Round, pen!.LineCap);
+        Assert.Equal(PenLineCap.Round, pen.LineCap);
         Assert.Equal(PenLineJoin.Bevel, pen.LineJoin);
     }
 
@@ -87,8 +89,8 @@ public class ShapeTests : ScopedTestBase
         });
 
         Assert.NotNull(pen);
-        Assert.NotNull(pen!.DashStyle);
-        Assert.Equal(3, pen.DashStyle!.Dashes.Count);
+        Assert.NotNull(pen.DashStyle);
+        Assert.Equal(3, pen.DashStyle!.Dashes!.Count);
         Assert.Equal(1, pen.DashStyle.Dashes[0]);
         Assert.Equal(2, pen.DashStyle.Dashes[1]);
         Assert.Equal(3, pen.DashStyle.Dashes[2]);
@@ -117,7 +119,7 @@ public class ShapeTests : ScopedTestBase
 
     private class TestShape : Shape
     {
-        protected override Geometry? CreateDefiningGeometry() =>
+        protected override Geometry CreateDefiningGeometry() =>
             new RectangleGeometry(new Rect(0, 0, 20, 20));
     }
 

tests/Avalonia.Controls.UnitTests/ToolTipTests.cs

@@ -42,9 +42,10 @@ namespace Avalonia.Controls.UnitTests
             }));
         }
 
-        public void Dispose()
+        public override void Dispose()
         {
             _toolTipOpenSubscription.Dispose();
+            base.Dispose();
         }
 
         protected override TestServices ConfigureServices(TestServices baseServices) =>

tests/Avalonia.Headless.UnitTests/IsolationTests.cs

@@ -15,6 +15,10 @@ public class IsolationTests
 #elif XUNIT
     [AvaloniaTheory]
     [InlineData(1), InlineData(2), InlineData(3)]
+    [System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessage(
+        "Usage",
+        "xUnit1026:Theory methods should use all of their parameters",
+        Justification = "Used to run the test several times with the proper isolation level")]
 #endif
     public void Application_Instance_Should_Match_Isolation_Level(int runIndex)
     {

tests/Avalonia.IntegrationTests.Appium/Avalonia.IntegrationTests.Appium.csproj

@@ -7,6 +7,12 @@
     <IsRunningAppium2 Condition="'$(IsRunningAppium2)' == ''">false</IsRunningAppium2>
     <DefineConstants Condition="'$(IsRunningAppium2)' == 'false'">$(DefineConstants);APPIUM1</DefineConstants>
     <DefineConstants Condition="'$(IsRunningAppium2)' == 'true'">$(DefineConstants);APPIUM2</DefineConstants>
+
+    <!--
+      References to System.Net.Http and System.Text.RegularExpressions are explicitly added to
+      avoid deprecated versions, we don't care about them not being pruned.
+    -->
+    <NoWarn>$(NoWarn);NU1510</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

tests/Avalonia.LeakTests/AvaloniaObjectTests.cs

@@ -54,7 +54,7 @@ namespace Avalonia.LeakTests
 
             Action completeSource = () =>
             {
-                ((ISubject<string>)weakSource.Target).OnCompleted();
+                ((ISubject<string>)weakSource.Target!).OnCompleted();
             };
 
             completeSource();

tests/Avalonia.LeakTests/ControlTests.cs

@@ -294,7 +294,7 @@ namespace Avalonia.LeakTests
                             {
                                 new FuncTreeDataTemplate<Node>(
                                     (x, _) => new TextBlock { Text = x.Name },
-                                    x => x.Children)
+                                    x => x.Children ?? [])
                             },
                             ItemsSource = nodes
                         }
@@ -409,7 +409,7 @@ namespace Avalonia.LeakTests
                 screens.Setup(x => x.ScreenFromWindow(It.IsAny<IWindowBaseImpl>())).Returns(screen1.Object);
 
                 var impl = new Mock<IWindowImpl>();
-                impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns(null);
+                impl.Setup(r => r.TryGetFeature(It.IsAny<Type>())).Returns((object?)null);
                 impl.SetupGet(x => x.RenderScaling).Returns(1);
                 impl.SetupProperty(x => x.Closed);
                 impl.Setup(x => x.Compositor).Returns(RendererMocks.CreateDummyCompositor());
@@ -516,7 +516,7 @@ namespace Avalonia.LeakTests
                 Assert.True(weakMenuItem2.IsAlive);
                 Assert.True(weakContextMenu.IsAlive);
 
-                Mock.Get(window.PlatformImpl).Invocations.Clear();
+                Mock.Get(window.PlatformImpl!).Invocations.Clear();
                 CollectGarbage();
 
                 Assert.False(weakMenuItem1.IsAlive);
@@ -605,7 +605,7 @@ namespace Avalonia.LeakTests
                 Assert.True(weakMenuItem4.IsAlive);
                 Assert.True(weakContextMenu2.IsAlive);
 
-                Mock.Get(window.PlatformImpl).Invocations.Clear();
+                Mock.Get(window.PlatformImpl!).Invocations.Clear();
                 CollectGarbage();
 
                 Assert.False(weakMenuItem1.IsAlive);
@@ -930,7 +930,7 @@ namespace Avalonia.LeakTests
                     window.Content = null;
                     
                     // Mock keep reference on a Popup via InvocationsCollection. So let's clear it before. 
-                    Mock.Get(window.PlatformImpl).Invocations.Clear();
+                    Mock.Get(window.PlatformImpl!).Invocations.Clear();
                     
                     return (new WeakReference(toolTip), new WeakReference(textBlock));
                 }
@@ -984,7 +984,7 @@ namespace Avalonia.LeakTests
                     window.Content = null;
 
                     // Mock keep reference on a Popup via InvocationsCollection. So let's clear it before. 
-                    Mock.Get(window.PlatformImpl).Invocations.Clear();
+                    Mock.Get(window.PlatformImpl!).Invocations.Clear();
                     
                     return (new WeakReference(flyout), new WeakReference(textBlock));
                 }
@@ -1093,8 +1093,8 @@ namespace Avalonia.LeakTests
 
         private class Node
         {
-            public string Name { get; set; }
-            public IEnumerable<Node> Children { get; set; }
+            public string? Name { get; set; }
+            public IEnumerable<Node>? Children { get; set; }
         }
 
     }

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

@@ -36,7 +36,7 @@ public class BindingTests_Delay : ScopedTestBase, IDisposable
         Assert.Equal(_source.Foo, _target.Text);
     }
 
-    public void Dispose()
+    public override void Dispose()
     {
         _app.Dispose();
         base.Dispose();

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs

@@ -2520,7 +2520,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
         public class NestedGeneric<T>
         {
-            public T Value { get; set; }
+            public T? Value { get; set; }
         }
     }
 

tests/Avalonia.RenderTests/CrossTests/Media/ImageScalingTests.cs

@@ -1,3 +1,5 @@
+#nullable enable
+
 using System.IO;
 using System.Runtime.CompilerServices;
 using Avalonia.Media.Imaging;

tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable enable
+
+using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
@@ -96,7 +98,7 @@ namespace Avalonia.Skia.UnitTests.Media
         }
 
         public bool TryCreateGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
-            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface glyphTypeface)
+            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             if (SystemFonts.TryGetGlyphTypeface(familyName, style, weight, stretch, out glyphTypeface))
             {
@@ -111,7 +113,7 @@ namespace Avalonia.Skia.UnitTests.Media
             return true;
         }
 
-        public bool TryCreateGlyphTypeface(Stream stream, FontSimulations fontSimulations, [NotNullWhen(true)] out IGlyphTypeface glyphTypeface)
+        public bool TryCreateGlyphTypeface(Stream stream, FontSimulations fontSimulations, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             var skTypeface = SKTypeface.FromStream(stream);
 

tests/Avalonia.UnitTests/HarfBuzzFontManagerImpl.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable enable
+
+using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
@@ -33,7 +35,7 @@ namespace Avalonia.UnitTests
 
         string[] IFontManagerImpl.GetInstalledFontFamilyNames(bool checkForUpdates)
         {
-            return _customTypefaces.Select(x => x.FontFamily!.Name).ToArray();
+            return _customTypefaces.Select(x => x.FontFamily.Name).ToArray();
         }
 
         public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fontWeight,
@@ -66,7 +68,7 @@ namespace Avalonia.UnitTests
         }
 
         public bool TryCreateGlyphTypeface(string familyName, FontStyle style, FontWeight weight, 
-            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface glyphTypeface)
+            FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
             glyphTypeface = null;
 

tests/Avalonia.UnitTests/TestRoot.cs

@@ -1,3 +1,5 @@
+#nullable enable
+
 using System;
 using System.Collections.Generic;
 using Avalonia.Controls;
@@ -28,17 +30,17 @@ namespace Avalonia.UnitTests
 
         class NullHitTester : IHitTester
         {
-            public IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool> filter) => Array.Empty<Visual>();
+            public IEnumerable<Visual> HitTest(Point p, Visual root, Func<Visual, bool>? filter) => Array.Empty<Visual>();
 
-            public Visual HitTestFirst(Point p, Visual root, Func<Visual, bool> filter) => null;
+            public Visual? HitTestFirst(Point p, Visual root, Func<Visual, bool>? filter) => null;
         }
 
-        public TestRoot(Control child)
+        public TestRoot(Control? child)
             : this(false, child)
         {
         }
 
-        public TestRoot(bool useGlobalStyles, Control child)
+        public TestRoot(bool useGlobalStyles, Control? child)
             : this()
         {
             if (useGlobalStyles)
@@ -63,17 +65,17 @@ namespace Avalonia.UnitTests
         IRenderer IRenderRoot.Renderer => Renderer;
         IHitTester IRenderRoot.HitTester => HitTester;
 
-        public IKeyboardNavigationHandler KeyboardNavigationHandler => null;
+        public IKeyboardNavigationHandler? KeyboardNavigationHandler => null;
         public IFocusManager FocusManager => _focusManager ??= new FocusManager(this);
-        public IPlatformSettings PlatformSettings => AvaloniaLocator.Current.GetService<IPlatformSettings>();
+        public IPlatformSettings? PlatformSettings => AvaloniaLocator.Current.GetService<IPlatformSettings>();
 
-        public IInputElement PointerOverElement { get; set; }
+        public IInputElement? PointerOverElement { get; set; }
         
         public bool ShowAccessKeys { get; set; }
 
-        public IStyleHost StylingParent { get; set; }
+        public IStyleHost? StylingParent { get; set; }
 
-        IStyleHost IStyleHost.StylingParent => StylingParent;
+        IStyleHost? IStyleHost.StylingParent => StylingParent;
 
         public IRenderTarget CreateRenderTarget()
         {

tests/Avalonia.UnitTests/ThreadRunHelper.cs

@@ -1,3 +1,5 @@
+#nullable enable
+
 using System;
 using System.Threading;
 using System.Threading.Tasks;

tests/Directory.Build.props

@@ -2,5 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <EnableNETAnalyzers>false</EnableNETAnalyzers>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
   </PropertyGroup>
 </Project>