feat: add composite type support for field resolvers

v2/pkg/ast/ast_selection.go

@@ -212,6 +212,18 @@ func (d *Document) SelectionSetHasFieldSelectionWithExactName(set int, name []by
 	return false, InvalidRef
 }
 
+// SelectionSetFieldRefs returns a list of field refs in the selection set.
+// It traverses through the field selections of the selection set and returns the actual field refs.
+func (d *Document) SelectionSetFieldRefs(set int) (refs []int) {
+	for _, selectionRef := range d.SelectionSets[set].SelectionRefs {
+		if d.Selections[selectionRef].Kind == SelectionKindField {
+			refs = append(refs, d.Selections[selectionRef].Ref)
+		}
+	}
+	return
+}
+
+// SelectionSetFieldSelections returns a list of field selection refs in the selection set.
 func (d *Document) SelectionSetFieldSelections(set int) (refs []int) {
 	for _, selectionRef := range d.SelectionSets[set].SelectionRefs {
 		if d.Selections[selectionRef].Kind == SelectionKindField {

v2/pkg/astvisitor/visitor.go

@@ -4021,6 +4021,7 @@ func (w *Walker) FieldDefinitionDirectiveArgumentValueByName(field int, directiv
 }
 
 // InRootField returns true if the current field is a root field.
+// This helper function can be used in EnterField and LeaveField.
 func (w *Walker) InRootField() bool {
 	return w.CurrentKind == ast.NodeKindField &&
 		len(w.Ancestors) == 2 &&

v2/pkg/engine/datasource/grpc_datasource/compiler.go

@@ -604,7 +604,7 @@
 		val := contextList.NewElement()
 		valMsg := val.Message()
 		for fieldName, value := range data {
 			p.setMessageValue(valMsg, fieldName, value)
 		}
 
 		contextList.Append(val)
@@ -625,10 +625,8 @@
 	if err != nil {
 		return nil, err
 	}
-
-	// Set the context and args fields
-	p.setMessageValue(rootMessage, contextSchemaField.Name, protoref.ValueOfList(contextList))
+	// Set the args field
 	p.setMessageValue(rootMessage, argsRPCField.Name, protoref.ValueOfMessage(args))
 
 	return rootMessage, nil
 }
@@ -736,7 +734,7 @@
 	switch fd.Kind() {
 	case protoref.MessageKind:
 		if fd.IsList() {
-			return []protoref.Value{field}
+			return []protoref.Value{protoref.ValueOfList(field.List())}
 		}
 
 		return p.resolveDataForPath(field.Message(), path[1:])
@@ -835,8 +833,33 @@
 	return msg.Mutable(msg.Descriptor().Fields().ByName(protoref.Name(name))).List()
 }
 
-func (p *RPCCompiler) setMessageValue(message protoref.Message, fieldName string, value protoref.Value) {
+func (p *RPCCompiler) setMessageValue(message protoref.Message, fieldName string, value protoref.Value) error {
+	fd := message.Descriptor().Fields().ByName(protoref.Name(fieldName))
+	if fd == nil {
+		return fmt.Errorf("field %s not found in message %s", fieldName, message.Descriptor().Name())
+	}
+
+	// If we are setting a list value here, we need to create a copy of the list
+	// because the field descriptor is included in the type check, so we cannot asign it using `Set` directly.
+	if fd.IsList() {
+		list := message.Mutable(fd).List()
+		source, ok := value.Interface().(protoref.List)
+		if !ok {
+			return fmt.Errorf("value is not a list")
+		}
+
+		p.copyListValues(source, list)
+		return nil
+	}
+
 	message.Set(message.Descriptor().Fields().ByName(protoref.Name(fieldName)), value)
+	return nil
+}
+
+func (p *RPCCompiler) copyListValues(source protoref.List, destination protoref.List) {
+	for i := range source.Len() {
+		destination.Append(source.Get(i))
+	}
 }
 
 // buildProtoMessage recursively builds a protobuf message from an RPCMessage definition