Avoid compiler error when using init properties with BindingSourceGenerator

src/Controls/src/BindingSourceGen/BindingSourceGenerator.cs

@@ -239,6 +239,7 @@ BinaryExpressionSyntax binary when binary.Kind() == SyntaxKind.AsExpression => b
 		static bool IsWritable(ISymbol? symbol)
 			=> symbol switch
 			{
+				IPropertySymbol { OriginalDefinition.SetMethod.IsInitOnly: true } => false,
 				IPropertySymbol propertySymbol => propertySymbol.SetMethod != null,
 				IFieldSymbol fieldSymbol => !fieldSymbol.IsReadOnly,
 				_ => true,

src/Controls/tests/BindingSourceGen.UnitTests/IntegrationTests.cs

@@ -1885,4 +1885,114 @@ internal static partial class GeneratedBindingInterceptors
             """,
 	result.GeneratedFiles["Path-To-Program.cs-GeneratedBindingInterceptors-17-23.g.cs"]);
 	}
+
+	[Fact]
+	public void GenerateSimpleBinding_WithInitSetter()
+	{
+		const string source =
+		"""
+		using Microsoft.Maui.Controls;
+		using MyNamespace; 
+
+		var label = new Label();
+		label.SetBinding(Label.TextProperty, static (MyClass c) => c.Text);
+
+		namespace MyNamespace
+		{
+		    public class MyClass
+			{
+				public required string Text { get; init; }
+			}
+		}
+		""";
+
+		var result = SourceGenHelpers.Run(source);
+		var actual = result.GeneratedFiles["Path-To-Program.cs-GeneratedBindingInterceptors-5-7.g.cs"];
+		AssertExtensions.AssertNoDiagnostics(result);
+
+		var id = Math.Abs(result.Binding!.SimpleLocation.GetHashCode());
+
+		AssertExtensions.CodeIsEqual(
+			$$"""
+            //------------------------------------------------------------------------------
+            // <auto-generated>
+            //     This code was generated by a .NET MAUI source generator.
+            //
+            //     Changes to this file may cause incorrect behavior and will be lost if
+            //     the code is regenerated.
+            // </auto-generated>
+            //------------------------------------------------------------------------------
+            #nullable enable
+
+            namespace System.Runtime.CompilerServices
+            {
+                using System;
+                using System.CodeDom.Compiler;
+
+                {{BindingCodeWriter.GeneratedCodeAttribute}}
+                [global::System.Diagnostics.Conditional("DEBUG")]
+                [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
+                file sealed class InterceptsLocationAttribute : Attribute
+                {
+                    public InterceptsLocationAttribute(int version, string data)
+                    {
+                        _ = version;
+                        _ = data;
+                    }
+                }
+            }
+
+            namespace Microsoft.Maui.Controls.Generated
+            {
+                using System;
+                using System.CodeDom.Compiler;
+                using System.Runtime.CompilerServices;
+                using Microsoft.Maui.Controls.Internals;
+
+                internal static partial class GeneratedBindingInterceptors
+                {
+
+                    {{BindingCodeWriter.GeneratedCodeAttribute}}
+                    [InterceptsLocationAttribute({{result.Binding.InterceptableLocation.Version}}, @"{{result.Binding.InterceptableLocation.Data}}")]
+                    public static void SetBinding{{id}}(
+                        this BindableObject bindableObject,
+                        BindableProperty bindableProperty,
+                        Func<global::MyNamespace.MyClass, string> getter,
+                        BindingMode mode = BindingMode.Default,
+                        IValueConverter? converter = null,
+                        object? converterParameter = null,
+                        string? stringFormat = null,
+                        object? source = null,
+                        object? fallbackValue = null,
+                        object? targetNullValue = null)
+                    {
+                        Action<global::MyNamespace.MyClass, string>? setter = null;
+                        if (ShouldUseSetter(mode, bindableProperty))
+                        {
+                            throw new InvalidOperationException("Cannot set value on the source object.");
+                        }
+
+                        var binding = new TypedBinding<global::MyNamespace.MyClass, string>(
+                            getter: source => (getter(source), true),
+                            setter,
+                            handlers: new Tuple<Func<global::MyNamespace.MyClass, object?>, string>[]
+                            {
+                                new(static source => source, "Text"),
+                            })
+                        {
+                            Mode = mode,
+                            Converter = converter,
+                            ConverterParameter = converterParameter,
+                            StringFormat = stringFormat,
+                            Source = source,
+                            FallbackValue = fallbackValue,
+                            TargetNullValue = targetNullValue
+                        };
+
+                        bindableObject.SetBinding(bindableProperty, binding);
+                    }
+                }
+            }
+            """, actual);
+	}
 }