Merge pull request #9774 from Youssef1313/avoid-throwing-roslyn-gen

fix: Avoid throwing in DependencyObjectGenerator when using Roslyn

src/SourceGenerators/Uno.UI.SourceGenerators.net6.Tests/DependencyObjectGeneratorTests/Given_DependenyObjectGenerator.cs

@@ -0,0 +1,52 @@
+using Microsoft.CodeAnalysis.Testing;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Uno.UI.SourceGenerators.DependencyObject;
+using Microsoft.CodeAnalysis.Testing.Verifiers;
+using System.Collections.Immutable;
+
+namespace Uno.UI.SourceGenerators.Tests.DependencyObjectGeneratorTests;
+
+[TestClass]
+public class Given_DependenyObjectGenerator
+{
+	private async Task TestAndroid(string testCode, params DiagnosticResult[] expectedDiagnostics)
+	{
+		var test = new CSharpSourceGeneratorTest<DependencyObjectGenerator, MSTestVerifier>()
+		{
+			TestState =
+			{
+				Sources = { testCode },
+			},
+			ReferenceAssemblies = ReferenceAssemblies.Net.Net60Android.AddPackages(ImmutableArray.Create(new PackageIdentity("Uno.UI", "4.4.20"))),
+		};
+		test.ExpectedDiagnostics.AddRange(expectedDiagnostics);
+		await test.RunAsync();
+	}
+
+	[TestMethod]
+	public async Task TestAndroidViewImplementingDependencyObject()
+	{
+		await TestAndroid(@"
+using Android.Content;
+using Windows.UI.Core;
+using Windows.UI.Xaml;
+
+public class C : Android.Views.View, DependencyObject
+{
+	public C(Context context) : base(context)
+	{
+	}
+
+	public CoreDispatcher Dispatcher { get; }
+	public object GetValue(DependencyProperty dp) => null;
+	public void SetValue(DependencyProperty dp, object value) { }
+	public void ClearValue(DependencyProperty dp) { }
+	public object ReadLocalValue(DependencyProperty dp) => null;
+	public object GetAnimationBaseValue(DependencyProperty dp) => null;
+	public long RegisterPropertyChangedCallback(DependencyProperty dp, DependencyPropertyChangedCallback callback) => 0;
+	public void UnregisterPropertyChangedCallback(DependencyProperty dp, long token) { }
+}",
+		// /0/Test0.cs(6,14): error Uno0003: 'Android.Views.View' shouldn't implement 'DependencyObject'. Inherit 'FrameworkElement' instead.
+		DiagnosticResult.CompilerError("Uno0003").WithSpan(6, 14, 6, 15).WithArguments("Android.Views.View"));
+	}
+}

src/SourceGenerators/Uno.UI.SourceGenerators/DependencyObject/DependencyObjectGenerator.Diagnostics.cs

@@ -0,0 +1,33 @@
+#nullable enable
+
+using System;
+using Microsoft.CodeAnalysis;
+
+#if NETFRAMEWORK
+using Uno.SourceGeneration;
+#endif
+
+namespace Uno.UI.SourceGenerators.DependencyObject;
+public partial class DependencyObjectGenerator
+{
+	private static readonly DiagnosticDescriptor _descriptor = new(
+#pragma warning disable RS2008 // Enable analyzer release tracking
+		id: "Uno0003",
+#pragma warning restore RS2008 // Enable analyzer release tracking
+		title: "Native view shouldn't implement 'DependencyObject'",
+		messageFormat: "'{0}' shouldn't implement 'DependencyObject'. Inherit 'FrameworkElement' instead.",
+		category: "Usage",
+		DiagnosticSeverity.Error,
+		isEnabledByDefault: true,
+		helpLinkUri: "https://github.com/unoplatform/uno/issues/6758#issuecomment-898544729",
+		customTags: WellKnownDiagnosticTags.NotConfigurable);
+
+	private static void ReportDiagnostic(GeneratorExecutionContext context, Diagnostic diagnostic)
+	{
+#if NETFRAMEWORK
+		throw new InvalidOperationException(diagnostic.GetMessage());
+#else
+		context.ReportDiagnostic(diagnostic);
+#endif
+	}
+}

src/SourceGenerators/Uno.UI.SourceGenerators/DependencyObject/DependencyObjectGenerator.cs

@@ -16,7 +16,7 @@
 namespace Uno.UI.SourceGenerators.DependencyObject
 {
 	[Generator]
-	public class DependencyObjectGenerator : ISourceGenerator
+	public partial class DependencyObjectGenerator : ISourceGenerator
 	{
 		public void Initialize(GeneratorInitializationContext context)
 		{
@@ -124,15 +124,18 @@ private void ProcessType(INamedTypeSymbol typeSymbol)
 					{
 						if (typeSymbol.Is(_iosViewSymbol))
 						{
-							throw new InvalidOperationException("A 'UIKit.UIView' shouldn't implement 'DependencyObject'. Inherit 'FrameworkElement' instead.");
+							ReportDiagnostic(_context, Diagnostic.Create(_descriptor, typeSymbol.Locations[0], "UIKit.UIView"));
+							return;
 						}
 						else if (typeSymbol.Is(_androidViewSymbol))
 						{
-							throw new InvalidOperationException("An 'Android.Views.View' shouldn't implement 'DependencyObject'. Inherit 'FrameworkElement' instead.");
+							ReportDiagnostic(_context, Diagnostic.Create(_descriptor, typeSymbol.Locations[0], "Android.Views.View"));
+							return;
 						}
 						else if (typeSymbol.Is(_macosViewSymbol))
 						{
-							throw new InvalidOperationException("An 'AppKit.NSView' shouldn't implement 'DependencyObject'. Inherit 'FrameworkElement' instead.");
+							ReportDiagnostic(_context, Diagnostic.Create(_descriptor, typeSymbol.Locations[0], "AppKit.NSView"));
+							return;
 						}
 					}