Add regression test for #34713: Binding with Converter and x:DataType is compiled

src/Controls/tests/Xaml.UnitTests/Issues/Maui34713.xaml

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+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+ xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+ xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+ x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui34713">
+<!-- NOTE: The converter is NOT defined in page resources.
+     It is expected to be in Application.Resources at runtime.
+     This tests the scenario from issue #34713. -->
+
+<VerticalStackLayout x:DataType="local:Maui34713ViewModel">
+<Label x:Name="label0" Text="{Binding IsActive, Converter={StaticResource BoolToTextConverter}}" />
+<Label x:Name="label1" Text="{Binding Name}" />
+</VerticalStackLayout>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui34713.xaml.cs

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+using System;
+using System.Globalization;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Dispatching;
+using Microsoft.Maui.UnitTests;
+using Xunit;
+
+using static Microsoft.Maui.Controls.Xaml.UnitTests.MockSourceGenerator;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui34713 : ContentPage
+{
+	public Maui34713()
+	{
+		InitializeComponent();
+	}
+
+	[Collection("Issue")]
+	public class Tests : IDisposable
+	{
+		public Tests()
+		{
+			DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+		}
+
+		public void Dispose()
+		{
+			AppInfo.SetCurrent(null);
+			Application.SetCurrentApplication(null);
+			DispatcherProvider.SetCurrent(null);
+		}
+
+		const string SharedCs = @"
+using System;
+using System.Globalization;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+namespace Microsoft.Maui.Controls.Xaml.UnitTests
+{
+public class Maui34713ViewModel { public bool IsActive { get; set; } public string Name { get; set; } = """"; }
+public class Maui34713BoolToTextConverter : IValueConverter {
+		public object Convert(object v, Type t, object p, CultureInfo c) => v is true ? ""Active"" : ""Inactive"";
+		public object ConvertBack(object v, Type t, object p, CultureInfo c) => throw new NotImplementedException();
+	}
+}";
+
+[Fact]
+internal void SourceGenResolvesConverterAtCompileTime_ImplicitResources()
+{
+	// When converter IS in page resources (implicit), source gen should
+	// resolve it at compile time - no runtime ProvideValue needed.
+	var xaml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
+<ContentPage xmlns=""http://schemas.microsoft.com/dotnet/2021/maui""
+xmlns:x=""http://schemas.microsoft.com/winfx/2009/xaml""
+xmlns:local=""clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests""
+x:Class=""Microsoft.Maui.Controls.Xaml.UnitTests.Maui34713Test1"">
+<ContentPage.Resources>
+<local:Maui34713BoolToTextConverter x:Key=""BoolToTextConverter"" />
+</ContentPage.Resources>
+<VerticalStackLayout x:DataType=""local:Maui34713ViewModel"">
+<Label x:Name=""label0"" Text=""{Binding IsActive, Converter={StaticResource BoolToTextConverter}}"" />
+</VerticalStackLayout>
+	</ContentPage>";
+
+	var cs = @"
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+namespace Microsoft.Maui.Controls.Xaml.UnitTests
+{
+[XamlProcessing(XamlInflator.Runtime, true)]
+public partial class Maui34713Test1 : ContentPage { public Maui34713Test1() { InitializeComponent(); } }
+	}" + SharedCs;
+
+	var result = CreateMauiCompilation()
+	.WithAdditionalSource(cs, hintName: "Maui34713Test1.xaml.cs")
+	.RunMauiSourceGenerator(new AdditionalXamlFile("Issues/Maui34713Test1.xaml", xaml, TargetFramework: "net10.0"));
+
+	var generated = result.GeneratedInitializeComponent();
+
+	Assert.Contains("TypedBinding", generated, StringComparison.Ordinal);
+	// Converter should be resolved at compile time - no ProvideValue call
+	Assert.DoesNotContain(".ProvideValue(", generated, StringComparison.Ordinal);
+}
+
+[Fact]
+internal void SourceGenResolvesConverterAtCompileTime_ExplicitResourceDictionary()
+{
+	// When converter IS in page resources (explicit RD), source gen should
+	// also resolve it at compile time.
+	var xaml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
+<ContentPage xmlns=""http://schemas.microsoft.com/dotnet/2021/maui""
+xmlns:x=""http://schemas.microsoft.com/winfx/2009/xaml""
+xmlns:local=""clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests""
+x:Class=""Microsoft.Maui.Controls.Xaml.UnitTests.Maui34713Test2"">
+<ContentPage.Resources>
+<ResourceDictionary>
+<local:Maui34713BoolToTextConverter x:Key=""BoolToTextConverter"" />
+</ResourceDictionary>
+</ContentPage.Resources>
+<VerticalStackLayout x:DataType=""local:Maui34713ViewModel"">
+<Label x:Name=""label0"" Text=""{Binding IsActive, Converter={StaticResource BoolToTextConverter}}"" />
+</VerticalStackLayout>
+	</ContentPage>";
+
+	var cs = @"
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+namespace Microsoft.Maui.Controls.Xaml.UnitTests
+{
+[XamlProcessing(XamlInflator.Runtime, true)]
+public partial class Maui34713Test2 : ContentPage { public Maui34713Test2() { InitializeComponent(); } }
+	}" + SharedCs;
+
+	var result = CreateMauiCompilation()
+	.WithAdditionalSource(cs, hintName: "Maui34713Test2.xaml.cs")
+	.RunMauiSourceGenerator(new AdditionalXamlFile("Issues/Maui34713Test2.xaml", xaml, TargetFramework: "net10.0"));
+
+	var generated = result.GeneratedInitializeComponent();
+
+	Assert.Contains("TypedBinding", generated, StringComparison.Ordinal);
+	// Converter should be resolved at compile time - no ProvideValue call
+	Assert.DoesNotContain(".ProvideValue(", generated, StringComparison.Ordinal);
+}
+
+[Fact]
+internal void SourceGenCompilesBindingWithConverterToTypedBinding()
+{
+	// When the converter is NOT in page resources, the binding should
+	// still be compiled into a TypedBinding.
+	var result = CreateMauiCompilation()
+	.WithAdditionalSource(
+	@"using System;
+	using System.Globalization;
+	using Microsoft.Maui.Controls;
+	using Microsoft.Maui.Controls.Xaml;
+
+	namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+	[XamlProcessing(XamlInflator.Runtime, true)]
+	public partial class Maui34713 : ContentPage
+	{
+		public Maui34713() => InitializeComponent();
+	}
+
+	public class Maui34713ViewModel
+	{
+		public bool IsActive { get; set; }
+		public string Name { get; set; } = string.Empty;
+	}
+
+	public class Maui34713BoolToTextConverter : IValueConverter
+	{
+		public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+		=> value is true ? ""Active"" : ""Inactive"";
+
+		public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+		=> throw new NotImplementedException();
+	}
+	")
+	.RunMauiSourceGenerator(typeof(Maui34713));
+
+	var generated = result.GeneratedInitializeComponent();
+
+	Assert.Contains("TypedBinding", generated, StringComparison.Ordinal);
+	Assert.Contains("Converter = extension.Converter", generated, StringComparison.Ordinal);
+	Assert.DoesNotContain("new global::Microsoft.Maui.Controls.Binding(", generated, StringComparison.Ordinal);
+}
+
+[Theory]
+[XamlInflatorData]
+internal void BindingWithConverterFromAppResourcesWorksCorrectly(XamlInflator inflator)
+{
+	var mockApp = new MockApplication();
+	mockApp.Resources.Add("BoolToTextConverter", new Maui34713BoolToTextConverter());
+	Application.SetCurrentApplication(mockApp);
+
+	var page = new Maui34713(inflator);
+	page.BindingContext = new Maui34713ViewModel { IsActive = true, Name = "Test" };
+
+	Assert.Equal("Active", page.label0.Text);
+	Assert.Equal("Test", page.label1.Text);
+}
+}
+}
+
+#nullable enable
+
+public class Maui34713ViewModel
+{
+	public bool IsActive { get; set; }
+	public string Name { get; set; } = string.Empty;
+}
+
+public class Maui34713BoolToTextConverter : IValueConverter
+{
+	public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+	=> value is true ? "Active" : "Inactive";
+
+	public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+	=> throw new NotImplementedException();
+}