feat: alias for enums

Author: ronimizy

samples/generators/SourceKit.Generators.Grpc.Samples/protos/model.proto

@@ -21,7 +21,7 @@ message ProtoModel {
   map<int32, string> map_value = 10;
 
   InnerMessage m = 11;
-  
+
   message InnerMessage {
     InnerEnum enum = 1;
   }
@@ -33,4 +33,8 @@ message ProtoModel {
 }
 
 message EmptyMessage {
+}
+
+enum OuterEnum {
+  UNSPECIFIED = 0;
 }

src/generators/SourceKit.Generators.Grpc/Constants.cs

@@ -4,11 +4,15 @@ internal static class Constants
 {
     public const string ProtobufNamespace = "Google.Protobuf";
     public const string ProtobufCollectionsNamespace = $"{ProtobufNamespace}.Collections";
+    public const string ProtobufReflectionNamespace = $"{ProtobufNamespace}.Reflection";
 
     public const string ProtobufMessageInterfaceFullyQualifiedName = $"{ProtobufNamespace}.IMessage";
 
+    public const string ProtobufOriginalNameAttributeFullyQualifiedName =
+        $"{ProtobufReflectionNamespace}.OriginalNameAttribute";
+
     public const string ProtobufRepeatedFieldFullyQualifiedName = $"{ProtobufCollectionsNamespace}.RepeatedField`1";
     public const string ProtobufMapFieldFullyQualifiedName = $"{ProtobufCollectionsNamespace}.MapField`2";
 
     public const string FilenameSuffix = "SourceKit.Generators.Grpc.g.cs";
-}
+}

src/generators/SourceKit.Generators.Grpc/Receivers/ProtoMessageAliasReceiver.cs

@@ -13,20 +13,41 @@ public void OnVisitSyntaxNode(GeneratorSyntaxContext context)
         INamedTypeSymbol? messageInterfaceSymbol = context.SemanticModel.Compilation
             .GetTypeByMetadataName(Constants.ProtobufMessageInterfaceFullyQualifiedName);
 
-        if (messageInterfaceSymbol is null)
+        INamedTypeSymbol? enumAttributeSymbol = context.SemanticModel.Compilation
+            .GetTypeByMetadataName(Constants.ProtobufOriginalNameAttributeFullyQualifiedName);
+
+        if (messageInterfaceSymbol is null || enumAttributeSymbol is null)
             return;
 
         ISymbol? symbolInfo = context.SemanticModel.GetDeclaredSymbol(context.Node);
 
         if (symbolInfo is not INamedTypeSymbol symbol)
             return;
 
-        if (symbol.AllInterfaces.Contains(messageInterfaceSymbol, SymbolEqualityComparer.Default) is false)
+        if (IsProtoClass(symbol) || IsProtoEnum(symbol))
             return;
 
         if (symbol.ContainingType is not null)
             return;
 
         _symbols.Add(symbol);
+
+        bool IsProtoClass(INamedTypeSymbol type)
+        {
+            return type.TypeKind is TypeKind.Class
+                   && type.AllInterfaces.Contains(messageInterfaceSymbol, SymbolEqualityComparer.Default) is false;
+        }
+
+        bool IsProtoEnum(INamedTypeSymbol type)
+        {
+            if (type.TypeKind is not TypeKind.Enum)
+                return false;
+
+            return type
+                .GetMembers()
+                .All(member => member.GetAttributes()
+                    .Any(attr => attr
+                        .AttributeClass?.Equals(enumAttributeSymbol, SymbolEqualityComparer.Default) is true));
+        }
     }
-}
+}