Fix value converters that also derive from MarkupExtension

Author: GeertvanHorrik

src/Catel.SourceGenerators/Extensions/INamedTypeSymbolExtensions.cs

@@ -1,48 +1,59 @@
-namespace Catel.SourceGenerators
+namespace Catel.SourceGenerators;
+
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+internal static class INamedTypeSymbolExtensions
 {
-    using System;
-    using System.Collections.Generic;
-    using System.Diagnostics;
-    using System.Linq;
-    using System.Text;
-    using System.Threading;
-    using Microsoft.CodeAnalysis;
-    using Microsoft.CodeAnalysis.CSharp.Syntax;
-
-    internal static class INamedTypeSymbolExtensions
+    public static bool HasStaticConstructorWithContent(this INamedTypeSymbol namedTypeSymbol)
     {
-        public static bool HasStaticConstructorWithContent(this INamedTypeSymbol namedTypeSymbol)
+        var staticCtor = namedTypeSymbol.Constructors.FirstOrDefault(x => x.IsStatic);
+        if (staticCtor is null)
+        {
+            return false;
+        }
+
+        var syntaxReferences = staticCtor.DeclaringSyntaxReferences;
+
+        foreach (var syntaxReference in syntaxReferences)
         {
-            var staticCtor = namedTypeSymbol.Constructors.FirstOrDefault(x => x.IsStatic);
-            if (staticCtor is null)
+            var constructorDeclarationSyntax = syntaxReference.GetSyntax() as ConstructorDeclarationSyntax;
+            if (constructorDeclarationSyntax is null)
+            {
+                continue;
+            }
+
+            var body = constructorDeclarationSyntax.Body;
+            if (body is null)
             {
                 return false;
             }
 
-            var syntaxReferences = staticCtor.DeclaringSyntaxReferences;
+            foreach (var childNode in body.ChildNodes())
+            {
+                // We found at least 1 child, thus body
+                return true;
+            }
+        }
+
+        return false;
+    }
 
-            foreach (var syntaxReference in syntaxReferences)
+    public static bool DerivesFromBaseClass(this INamedTypeSymbol classSymbol, string typeName)
+    {
+        var baseType = classSymbol.BaseType;
+        while (baseType is not null)
+        {
+            var displayString = baseType.ToDisplayString();
+            if (displayString == typeName)
             {
-                var constructorDeclarationSyntax = syntaxReference.GetSyntax() as ConstructorDeclarationSyntax;
-                if (constructorDeclarationSyntax is null)
-                {
-                    continue;
-                }
-
-                var body = constructorDeclarationSyntax.Body;
-                if (body is null)
-                {
-                    return false;
-                }
-
-                foreach (var childNode in body.ChildNodes())
-                {
-                    // We found at least 1 child, thus body
-                    return true;
-                }
+                return true;
             }
 
-            return false;
+            baseType = baseType.BaseType;
         }
+
+        return false;
     }
 }

src/Catel.SourceGenerators/XamlConstructors/MarkupExtensionsConstructorsSourceGenerator.cs

@@ -73,19 +73,7 @@ private static bool IsSyntaxTargetForGeneration(SyntaxNode node)
                 return null;
             }
 
-            var baseType = classSymbol.BaseType;
-            while (baseType is not null)
-            {
-                var displayString = baseType.ToDisplayString();
-                if (displayString == "System.Windows.Markup.MarkupExtension")
-                {
-                    break;
-                }
-
-                baseType = baseType.BaseType;
-            }
-
-            if (baseType is null)
+            if (!classSymbol.DerivesFromBaseClass("System.Windows.Markup.MarkupExtension"))
             {
                 return null;
             }

src/Catel.SourceGenerators/XamlConstructors/ValueConverterConstructorsSourceGenerator.cs

@@ -72,6 +72,12 @@ private static bool IsSyntaxTargetForGeneration(SyntaxNode node)
                 return null;
             }
 
+            // Already handled by markup extension constructor source generator
+            if (classSymbol.DerivesFromBaseClass("System.Windows.Markup.MarkupExtension"))
+            {
+                return null;
+            }
+
             var emptyClassConstructor = classSymbol.Constructors.FirstOrDefault(x => !x.IsStatic && x.Parameters.Length == 0);
             if (emptyClassConstructor is not null)
             {