Integration tests

src/Controls/src/BindingSourceGen/BindingCodeWriter.cs

@@ -12,7 +12,17 @@ public sealed class BindingCodeWriter
 {
 	public static string GeneratedCodeAttribute => $"[GeneratedCodeAttribute(\"{typeof(BindingCodeWriter).Assembly.FullName}\", \"{typeof(BindingCodeWriter).Assembly.GetName().Version}\")]";
 
-	public string GenerateCode() => $$"""
+	public string GenerateCode()
+	{
+		if (_bindings.Count == 0)
+		{
+			return string.Empty;
+		}
+
+		return DoGenerateCode();
+	}
+
+	private string DoGenerateCode() => $$"""
 		//------------------------------------------------------------------------------
 		// <auto-generated>
 		//     This code was generated by a .NET MAUI source generator.
@@ -26,11 +36,22 @@ public string GenerateCode() => $$"""
 		namespace System.Runtime.CompilerServices
 		{
 			using System;
+			using System.CodeDom.Compiler;
 
 			{{GeneratedCodeAttribute}}
 			[AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
-			file sealed class InterceptsLocationAttribute(string filePath, int line, int column) : Attribute
+			file sealed class InterceptsLocationAttribute : Attribute
 			{
+				public InterceptsLocationAttribute(string filePath, int line, int column)
+				{
+					FilePath = filePath;
+					Line = line;
+					Column = column;
+				}
+
+				public string FilePath { get; }
+				public int Line { get; }
+				public int Column { get; }
 			}
 		}
 
@@ -39,7 +60,7 @@ namespace Microsoft.Maui.Controls.Generated
 			using System;
 			using System.CodeDom.Compiler;
 			using System.Runtime.CompilerServices;
-			using Microsoft.Maui.Controls.Internal;
+			using Microsoft.Maui.Controls.Internals;
 
 			{{GeneratedCodeAttribute}}
 			file static class GeneratedBindableObjectExtensions
@@ -120,7 +141,7 @@ public void AppendSetBindingInterceptor(int id, CodeWriterBinding binding)
 					object? targetNullValue = null)
 				{
 					var binding = new TypedBinding<{{binding.SourceType}}, {{binding.PropertyType}}>(
-						getter: static source => (getter(source), true),
+						getter: source => (getter(source), true),
 				""");
 
 			Indent();
@@ -165,31 +186,34 @@ private void AppendInterceptorAttribute(SourceCodeLocation location)
 			AppendLine($"[InterceptsLocationAttribute(@\"{location.FilePath}\", {location.Line}, {location.Column})]");
 		}
 
+		// TODO: The setter action is broken at the moment, it needs to be changed completely:
+		// 	- see https://sharplab.io/#v2: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=
 		private void AppendSetterAction(IPathPart[] path)
 		{
-			AppendLine("static (source, value) => ");
-			AppendLine('{');
-			Indent();
-
-			if (path.Any(part => part.IsConditional))
-			{
-				Append("if (");
-				Append(_accessExpressionBuilder.BuildExpression("source", path, depth: path.Length - 1));
-				AppendLine($" is null)");
-				AppendLines(
-					"""
-					{
-					    return;
-					}
-
-					""");
-			}
-
-			Append(_accessExpressionBuilder.BuildExpression("source", path, unsafeAccess: true));
-			AppendLine(" = value;");
-
-			Unindent();
-			Append('}');
+			throw new NotImplementedException();
+			// AppendLine("static (source, value) => ");
+			// AppendLine('{');
+			// Indent();
+
+			// if (path.Any(part => part.IsConditional))
+			// {
+			// 	Append("if (");
+			// 	Append(_accessExpressionBuilder.BuildExpression("source", path, depth: path.Length - 1));
+			// 	AppendLine($" is null)");
+			// 	AppendLines(
+			// 		"""
+			// 		{
+			// 		    return;
+			// 		}
+
+			// 		""");
+			// }
+
+			// Append(_accessExpressionBuilder.BuildExpression("source", path, unsafeAccess: true));
+			// AppendLine(" = value;");
+
+			// Unindent();
+			// Append('}');
 		}
 
 		private void AppendHandlersArray(TypeDescription sourceType, IPathPart[] path)

src/Controls/src/BindingSourceGen/BindingSourceGenerator.cs

@@ -58,8 +58,10 @@ static bool IsSetBindingMethod(SyntaxNode node)
 	static BindingDiagnosticsWrapper GetBindingForGeneration(GeneratorSyntaxContext context, CancellationToken t)
 	{
 		var diagnostics = new List<Diagnostic>();
-		var invocation = (InvocationExpressionSyntax)context.Node;
+		NullableContext nullableContext = context.SemanticModel.GetNullableContext(context.Node.Span.Start);
+		var enabledNullable = (nullableContext & NullableContext.Enabled) == NullableContext.Enabled;
 
+		var invocation = (InvocationExpressionSyntax)context.Node;
 		var method = (MemberAccessExpressionSyntax)invocation.Expression;
 
 		var sourceCodeLocation = new SourceCodeLocation(
@@ -82,27 +84,25 @@ static BindingDiagnosticsWrapper GetBindingForGeneration(GeneratorSyntaxContext
 			return ReportDiagnostics(lambdaDiagnostics);
 		}
 
-		NullableContext nullableContext = context.SemanticModel.GetNullableContext(context.Node.Span.Start);
-		var enabledNullable = (nullableContext & NullableContext.Enabled) == NullableContext.Enabled;
-		var parts = new List<IPathPart>();
-		var correctlyParsed = PathParser.ParsePath(lambdaBody, enabledNullable, context, parts);
-
-		if (!correctlyParsed)
+		var lambdaTypeInfo = context.SemanticModel.GetTypeInfo(lambdaBody, t);
+		if (lambdaTypeInfo.Type == null)
 		{
-			return ReportDiagnostics([DiagnosticsFactory.UnableToResolvePath(lambdaBody.GetLocation())]);
+			return ReportDiagnostics([DiagnosticsFactory.UnableToResolvePath(lambdaBody.GetLocation())]); // TODO: New diagnostic
 		}
 
-		// Sometimes analysing just the return type of the lambda is not enough. TODO: Refactor
-		// var propertyType = BindingGenerationUtilities.CreateTypeNameFromITypeSymbol(lambdaSymbol.ReturnType, enabledNullable);
-		// var lastMember = parts.Last() is Cast cast ? cast.Part : parts.Last();
-		// propertyType = propertyType with { IsNullable = lastMember is ConditionalAccess || propertyType.IsNullable };
+		var pathParser = new PathParser(context);
+		var (pathDiagnostics, parts) = pathParser.ParsePath(lambdaBody);
+		if (pathDiagnostics.Length > 0)
+		{
+			return ReportDiagnostics(pathDiagnostics);
+		}
 
 		var codeWriterBinding = new CodeWriterBinding(
 			Location: sourceCodeLocation,
 			SourceType: BindingGenerationUtilities.CreateTypeNameFromITypeSymbol(lambdaSymbol.Parameters[0].Type, enabledNullable),
-			PropertyType: BindingGenerationUtilities.CreateTypeNameFromITypeSymbol(lambdaSymbol.ReturnType, enabledNullable),
+			PropertyType: BindingGenerationUtilities.CreateTypeNameFromITypeSymbol(lambdaTypeInfo.Type, enabledNullable),
 			Path: parts.ToArray(),
-			GenerateSetter: true //TODO: Implement
+			GenerateSetter: false //TODO: Implement
 		);
 		return new BindingDiagnosticsWrapper(codeWriterBinding, diagnostics.ToArray());
 	}
@@ -150,52 +150,6 @@ private static (ExpressionSyntax? lambdaBodyExpression, IMethodSymbol? lambdaSym
 	private static BindingDiagnosticsWrapper ReportDiagnostics(Diagnostic[] diagnostics) => new(null, diagnostics);
 }
 
-internal static class BindingGenerationUtilities
-{
-	internal static bool IsTypeNullable(ITypeSymbol typeInfo, bool enabledNullable)
-	{
-		if (!enabledNullable && typeInfo.IsReferenceType)
-		{
-			return true;
-		}
-
-		if (typeInfo.NullableAnnotation == NullableAnnotation.Annotated)
-		{
-			return true;
-		}
-
-		return typeInfo is INamedTypeSymbol namedTypeSymbol
-			&& namedTypeSymbol.IsGenericType
-			&& namedTypeSymbol.ConstructedFrom.SpecialType == SpecialType.System_Nullable_T;
-	}
-
-	internal static TypeDescription CreateTypeNameFromITypeSymbol(ITypeSymbol typeSymbol, bool enabledNullable)
-	{
-		var (isNullable, name) = GetNullabilityAndName(typeSymbol, enabledNullable);
-		return new TypeDescription(
-			GlobalName: name,
-			IsNullable: isNullable,
-			IsGenericParameter: typeSymbol.Kind == SymbolKind.TypeParameter,
-			IsValueType: typeSymbol.IsValueType);
-	}
-
-	internal static (bool, string) GetNullabilityAndName(ITypeSymbol typeSymbol, bool enabledNullable)
-	{
-		if (typeSymbol.IsReferenceType && (typeSymbol.NullableAnnotation == NullableAnnotation.Annotated || !enabledNullable))
-		{
-			return (true, typeSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat));
-		}
-
-		if (IsTypeNullable(typeSymbol, enabledNullable))
-		{
-			var type = ((INamedTypeSymbol)typeSymbol).TypeArguments[0];
-			return (true, type.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat));
-		}
-
-		return (false, typeSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat));
-	}
-}
-
 public sealed record BindingDiagnosticsWrapper(
 	CodeWriterBinding? Binding,
 	Diagnostic[] Diagnostics);

src/Controls/src/BindingSourceGen/BindingSourceGeneratorUtilities.cs

@@ -0,0 +1,57 @@
+using Microsoft.CodeAnalysis;
+
+namespace Microsoft.Maui.Controls.BindingSourceGen;
+
+internal static class BindingGenerationUtilities
+{
+    internal static bool IsTypeNullable(ITypeSymbol typeInfo, bool enabledNullable)
+    {
+        if (!enabledNullable && typeInfo.IsReferenceType)
+        {
+            return true;
+        }
+
+        if (typeInfo.NullableAnnotation == NullableAnnotation.Annotated)
+        {
+            return true;
+        }
+
+        return typeInfo is INamedTypeSymbol namedTypeSymbol
+            && namedTypeSymbol.IsGenericType
+            && namedTypeSymbol.ConstructedFrom.SpecialType == SpecialType.System_Nullable_T;
+    }
+
+    internal static TypeDescription CreateTypeNameFromITypeSymbol(ITypeSymbol typeSymbol, bool enabledNullable)
+    {
+        var isNullable = IsTypeNullable(typeSymbol, enabledNullable);
+        return new TypeDescription(
+            GlobalName: GetGlobalName(typeSymbol, isNullable, typeSymbol.IsValueType),
+            IsNullable: isNullable,
+            IsGenericParameter: typeSymbol.Kind == SymbolKind.TypeParameter,
+            IsValueType: typeSymbol.IsValueType);
+    }
+
+    internal static TypeDescription CreateTypeDescriptionForCast(ITypeSymbol typeSymbol)
+    {
+        // We can cast to nullable value type or non-nullable reference type
+        var name = typeSymbol.IsValueType ?
+            ((INamedTypeSymbol)typeSymbol).TypeArguments[0].ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat) :
+            typeSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
+
+        return new TypeDescription(
+            GlobalName: name,
+            IsNullable: typeSymbol.IsValueType,
+            IsGenericParameter: typeSymbol.Kind == SymbolKind.TypeParameter,
+            IsValueType: typeSymbol.IsValueType);
+    }
+
+    internal static string GetGlobalName(ITypeSymbol typeSymbol, bool IsNullable, bool IsValueType)
+    {
+        if (IsNullable && IsValueType)
+        {
+            return ((INamedTypeSymbol)typeSymbol).TypeArguments[0].ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
+        }
+
+        return typeSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
+    }
+}