Add error details for bad request

grpc/error.go

@@ -0,0 +1,31 @@
+package grpc
+
+import (
+	validation "github.com/go-ozzo/ozzo-validation/v4"
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func validationStatusError(code codes.Code, msg string, err error) *status.Status {
+	st := status.New(code, msg)
+
+	switch t := err.(type) {
+	case validation.Errors:
+		br := &errdetails.BadRequest{}
+		for id, e := range t {
+			ve := e.(validation.Error)
+			v := &errdetails.BadRequest_FieldViolation{
+				Field:       id,
+				Description: ve.Message(),
+			}
+			br.FieldViolations = append(br.FieldViolations, v)
+		}
+		newSt, err := st.WithDetails(br)
+		if err == nil {
+			return newSt
+		}
+	}
+
+	return st
+}

grpc/message_handler.go

@@ -49,7 +49,8 @@ func (m *MessageHandler) CreateMessage(ctx context.Context, request *pb.CreateMe
 	// Validate message
 	err := message.Validate()
 	if err != nil {
-		return &pb.Message{}, status.Error(codes.InvalidArgument, "invalid_message")
+		st := validationStatusError(codes.InvalidArgument, "invalid_message", err)
+		return &pb.Message{}, st.Err()
 	}
 
 	// Create Message

grpc/subscription_handler.go

@@ -62,7 +62,8 @@ func (s *SubscriptionHandler) CreateSubscription(ctx context.Context, request *p
 	// Validate subscription
 	err := subscription.Validate()
 	if err != nil {
-		return &pb.Subscription{}, status.Error(codes.InvalidArgument, "invalid_subscription")
+		st := validationStatusError(codes.InvalidArgument, "invalid_subscription", err)
+		return &pb.Subscription{}, st.Err()
 	}
 
 	// Create subscription

grpc/topic_handler.go

@@ -50,7 +50,8 @@ func (t *TopicHandler) CreateTopic(ctx context.Context, request *pb.CreateTopicR
 	// Validate topic
 	err := topic.Validate()
 	if err != nil {
-		return &pb.Topic{}, status.Error(codes.InvalidArgument, "invalid_topic")
+		st := validationStatusError(codes.InvalidArgument, "invalid_topic", err)
+		return &pb.Topic{}, st.Err()
 	}
 
 	// Create topic