Merge pull request #2963 from unoplatform/copilot/fix-bindable-attribute-issue

Add BindableAttribute to ViewModelGenerator_1 and ViewModelGenerator_2

Author: dr1rrb

src/Uno.Extensions.Reactive.Generator/Bindables/ViewModelGenerator_1.cs

@@ -159,6 +159,7 @@ string GetPropertyInfo(ITypeSymbol type, (ITypeSymbol type, Func<string, string>
 namespace {record.ContainingNamespace}
 {{
 	{this.GetCodeGenAttribute()}
+	[{NS.Bindings}.Bindable(typeof({record.ToFullString()}))]
 	{record.GetAccessibilityAsCSharpCodeString()} sealed class Bindable{record.GetPascalCaseName()} : {NS.Bindings}.Bindable<{record}>
 	{{
 		{properties.Select(prop => $"private readonly {prop.bindable} _{prop.symbol.GetCamelCaseName()};").Align(2)}

src/Uno.Extensions.Reactive.Generator/Bindables/ViewModelGenerator_2.cs

@@ -162,6 +162,7 @@ string GetPropertyInfo(ITypeSymbol type, (ITypeSymbol type, Func<string, string>
 namespace {record.ContainingNamespace}
 {{
 	{this.GetCodeGenAttribute()}
+	[{NS.Bindings}.Bindable(typeof({record.ToFullString()}))]
 	{record.GetAccessibilityAsCSharpCodeString()} sealed class {vm} : {NS.Bindings}.Bindable<{record}>
 	{{
 		{properties.Select(prop => $"private readonly {prop.bindable} _{prop.symbol.GetCamelCaseName()};").Align(2)}

src/Uno.Extensions.Reactive.Tests/Generator/Given_BindableAttribute_Then_Flagged.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Reflection;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Uno.Extensions.Reactive.Bindings;
+using Uno.Extensions.Reactive.Testing;
+
+namespace Uno.Extensions.Reactive.Tests.Generator;
+
+/// <summary>
+/// Tests to verify that generated bindable types are flagged with the BindableAttribute.
+/// This ensures better performance and trimming support by avoiding reflection at runtime.
+/// </summary>
+[TestClass]
+public partial class Given_BindableAttribute_Then_Flagged : FeedUITests
+{
+	[TestMethod]
+	public void ViewModelGenerator_GeneratesBindableAttributeForRecords()
+	{
+		// When ViewModelGenerator_2 generates a bindable wrapper for a record type,
+		// it should include the BindableAttribute to avoid reflection at runtime.
+		// ViewModelGenerator_2 generates types named Bindable{RecordName}ViewModel
+		var bindableType = typeof(BindableTestRecordViewModel);
+		
+		Assert.IsNotNull(bindableType, "The generated bindable type should exist");
+		
+		var bindableAttribute = bindableType.GetCustomAttribute<BindableAttribute>();
+		Assert.IsNotNull(bindableAttribute, "The generated bindable type should have BindableAttribute");
+		Assert.AreEqual(typeof(TestRecord), bindableAttribute.Model, "The BindableAttribute should reference the correct model type");
+	}
+
+	[TestMethod]
+	public void ViewModelGenTool_3_GeneratesBindableAttribute()
+	{
+		// ViewModelGenTool_3 generates types named {ModelName}ViewModel (for ViewModels with partial class)
+		var bindableType = typeof(TestViewModel);
+		
+		Assert.IsNotNull(bindableType, "The generated bindable type should exist");
+		
+		var bindableAttribute = bindableType.GetCustomAttribute<BindableAttribute>();
+		Assert.IsNotNull(bindableAttribute, "The generated bindable type should have BindableAttribute");
+		Assert.AreEqual(typeof(TestModel), bindableAttribute.Model, "The BindableAttribute should reference the correct model type");
+	}
+
+	[TestMethod]
+	public void ViewModelGenerator_GeneratesBindableAttributeForNestedRecords()
+	{
+		// Test that records containing other records also generate the BindableAttribute
+		var bindableType = typeof(BindableTestRecordWithListViewModel);
+		
+		Assert.IsNotNull(bindableType, "The generated bindable type should exist");
+		
+		var bindableAttribute = bindableType.GetCustomAttribute<BindableAttribute>();
+		Assert.IsNotNull(bindableAttribute, "The generated bindable type should have BindableAttribute");
+		Assert.AreEqual(typeof(TestRecordWithList), bindableAttribute.Model, "The BindableAttribute should reference the correct model type");
+	}
+}
+
+// Test model for ViewModelGenTool_3 (generates view models from partial classes with feeds)
+// This will trigger generation of bindable wrappers for the records it references
+public partial class TestModel
+{
+	public IFeed<TestRecord> Record => Feed.Async(async ct => new TestRecord("Test", 42));
+	public IFeed<TestRecordWithList> RecordWithList => Feed.Async(async ct => new TestRecordWithList(ImmutableList<TestRecord>.Empty));
+}
+
+// Test record for ViewModelGenerator_2 (generates bindable wrappers for records)
+public partial record TestRecord(string Name, int Value);
+
+// Test record with nested list to verify complex scenarios
+public partial record TestRecordWithList(ImmutableList<TestRecord> Items);

src/Uno.Extensions.Reactive/Presentation/Bindings/BindableAttribute.cs

@@ -7,7 +7,11 @@ namespace Uno.Extensions.Reactive.Bindings;
 /// <summary>
 /// Flags a class as a _bindable_ (a.k.a. _view model_).
 /// </summary>
-/// <remarks>This attribute is added by the feeds generator on the _view model_ type, you should not have to use it.</remarks>
+/// <remarks>
+/// This attribute is added by the feeds generator on the _view model_ type, you should not have to use it.
+/// This attribute is used at compile-time by Uno Platform and WinAppSDK to generate bindings.
+/// Note: The binding generators validate only the attribute name, not the namespace.
+/// </remarks>
 [EditorBrowsable(EditorBrowsableState.Advanced)]
 [AttributeUsage(AttributeTargets.Class)]
 public class BindableAttribute : Attribute