Fixed the review comments

Assisted by [Claude Code](https://claude.ai/code)

Signed-off-by: Prabodh Chaudhari <[email protected]>

Author: prabodhcs

cmd/mailing-list-api/service/service_response_converters.go

@@ -137,6 +137,10 @@ func (s *mailingListService) convertGrpsIOMailingListDomainToResponse(ml *model.
 
 // convertGrpsIOMailingListDomainToStandardResponse converts a domain mailing list to GOA standard response type
 func (s *mailingListService) convertGrpsIOMailingListDomainToStandardResponse(mailingList *model.GrpsIOMailingList) *mailinglistservice.GrpsIoMailingListWithReadonlyAttributes {
+	if mailingList == nil {
+		return &mailinglistservice.GrpsIoMailingListWithReadonlyAttributes{}
+	}
+
 	response := &mailinglistservice.GrpsIoMailingListWithReadonlyAttributes{
 		UID:              &mailingList.UID,
 		GroupName:        &mailingList.GroupName,

cmd/mailing-list-api/service/service_validators.go

@@ -275,7 +275,7 @@ func validateMailingListUpdate(ctx context.Context, existing *model.GrpsIOMailin
 	}
 
 	// Validate main group restrictions (critical business rule from Groups.io)
-	if parentService != nil && existing.IsMainGroup(parentService) {
+	if parentService != nil && isMainGroupForService(existing, parentService) {
 		// Main groups must remain public announcement lists
 		if payload.Type != nil && *payload.Type != "announcement" {
 			return errors.NewValidation("main group must be an announcement list")
@@ -360,20 +360,8 @@ func validateMailingListUpdate(ctx context.Context, existing *model.GrpsIOMailin
 // validateMailingListDeleteProtection validates deletion protection rules
 func validateMailingListDeleteProtection(mailingList *model.GrpsIOMailingList, parentService *model.GrpsIOService) error {
 	// Check if it's a main group (any service type)
-	if parentService != nil {
-		isMainGroup := false
-
-		switch parentService.Type {
-		case "primary":
-			isMainGroup = mailingList.GroupName == parentService.GroupName
-		case "formation", "shared":
-			// Formation and shared services use prefix as main group identifier
-			isMainGroup = mailingList.GroupName == parentService.Prefix
-		}
-
-		if isMainGroup {
-			return errors.NewValidation(fmt.Sprintf("cannot delete the main group of a %s service", parentService.Type))
-		}
+	if parentService != nil && isMainGroupForService(mailingList, parentService) {
+		return errors.NewValidation(fmt.Sprintf("cannot delete the main group of a %s service", parentService.Type))
 	}
 
 	// Protect announcement lists (typically used for critical communications)
@@ -436,6 +424,18 @@ func contains(slice []string, item string) bool {
 	return false
 }
 
+// isMainGroupForService determines if a list is the "main" group for its parent.
+func isMainGroupForService(ml *model.GrpsIOMailingList, svc *model.GrpsIOService) bool {
+	switch svc.Type {
+	case "primary":
+		return ml.GroupName == svc.GroupName
+	case "formation", "shared":
+		return ml.GroupName == svc.Prefix
+	default:
+		return false
+	}
+}
+
 // validateMemberUpdate validates that immutable fields are not changed during updates
 func validateMemberUpdate(existing, updated *model.GrpsIOMember) error {
 	if existing == nil || updated == nil {

internal/infrastructure/nats/storage.go

@@ -805,6 +805,10 @@ func (s *storage) UpdateGrpsIOMember(ctx context.Context, uid string, member *mo
 
 // DeleteGrpsIOMember deletes a member with optimistic concurrency control
 func (s *storage) DeleteGrpsIOMember(ctx context.Context, uid string, expectedRevision uint64, member *model.GrpsIOMember) error {
+	if member == nil {
+		return errs.NewValidation("member is required for deletion")
+	}
+
 	slog.DebugContext(ctx, "nats storage: deleting member",
 		"member_uid", uid,
 		"expected_revision", expectedRevision)

pkg/utils/time_helpers.go

@@ -18,7 +18,7 @@ func ValidateRFC3339(timestamp string) (time.Time, error) {
 		return time.Time{}, fmt.Errorf(constants.ErrEmptyTimestamp)
 	}
 
-	t, err := time.Parse(constants.TimestampFormat, timestamp)
+	t, err := time.Parse(time.RFC3339Nano, timestamp)
 	if err != nil {
 		return time.Time{}, fmt.Errorf("%s: %w", constants.ErrInvalidTimestampFormat, err)
 	}