fix: nats publisher func to encode req

transport/nats/publisher_fn.go

@@ -3,19 +3,21 @@ package nats
 import (
 	"context"
 	"encoding/json"
+
+	"github.com/nats-io/nats.go"
 	natn "github.com/nats-io/nats.go"
 )
 
 // EncodeJSONRequest is an Encoder that serializes the request as a
 // JSON object to the Data of the Msg. Many JSON-over-NATS services can use it as
 // a sensible default.
-func EncodeJSONRequest(_ context.Context, msg *natn.Msg, request interface{}) error {
+func EncodeJSONRequest(_ context.Context, msg *natn.Msg, request interface{}) (*nats.Msg, error) {
 	b, err := json.Marshal(request)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	msg.Data = b
 
-	return nil
+	return msg, nil
 }