Disable validation/recipient generator for abstract types

Author: Sergio0694

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs

@@ -20,13 +20,15 @@ public sealed partial class ObservableValidatorValidateAllPropertiesGenerator :
     /// <inheritdoc/>
     public void Initialize(IncrementalGeneratorInitializationContext context)
     {
-        // Get all class declarations
+        // Get all class declarations. We intentionally skip generating code for abstract types, as that would never be used.
+        // The methods that are generated by this generator are retrieved through reflection using the type of the invoking
+        // instance as discriminator, which means a type that is abstract could never be used (since it couldn't be instantiated).
         IncrementalValuesProvider<INamedTypeSymbol> typeSymbols =
             context.SyntaxProvider
             .CreateSyntaxProvider(
                 static (node, _) => node is ClassDeclarationSyntax,
                 static (context, _) => (context.Node, Symbol: (INamedTypeSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node)!))
-            .Where(static item => item.Node.IsFirstSyntaxDeclarationForSymbol(item.Symbol))
+            .Where(static item => !item.Symbol.IsAbstract && item.Node.IsFirstSyntaxDeclarationForSymbol(item.Symbol))
             .Select(static (item, _) => item.Symbol);
 
         // Get the types that inherit from ObservableValidator and gather their info

CommunityToolkit.Mvvm.SourceGenerators/Messaging/IMessengerRegisterAllGenerator.cs

@@ -25,12 +25,13 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         // definitions (it might happen if a recipient has partial declarations). To do this, all pairs
         // of class declarations and associated symbols are gathered, and then only the pair where the
         // class declaration is the first syntax reference for the associated symbol is kept.
+        // Just like with the ObservableValidator generator, we also intentionally skip abstract types.
         IncrementalValuesProvider<INamedTypeSymbol> typeSymbols =
             context.SyntaxProvider
             .CreateSyntaxProvider(
                 static (node, _) => node is ClassDeclarationSyntax,
                 static (context, _) => (context.Node, Symbol: (INamedTypeSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node)!))
-            .Where(static item => item.Node.IsFirstSyntaxDeclarationForSymbol(item.Symbol))
+            .Where(static item => !item.Symbol.IsAbstract && item.Node.IsFirstSyntaxDeclarationForSymbol(item.Symbol))
             .Select(static (item, _) => item.Symbol);
 
         // Get the target IRecipient<TMessage> interfaces and filter out other types