fix: nats publisher func to encode req

transport/nats/publisher_fn.go

@@ -1,21 +1,31 @@
 package nats
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+
+	"github.com/nats-io/nats.go"
 	natn "github.com/nats-io/nats.go"
+	"github.com/unbxd/go-base/v2/errors"
 )
 
 // 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 {
-	b, err := json.Marshal(request)
+func EncodeJSONRequest(_ context.Context, subject string, request interface{}) (*nats.Msg, error) {
+	var (
+		buf bytes.Buffer
+		err error
+	)
+
+	err = json.NewEncoder(&buf).Encode(request)
 	if err != nil {
-		return err
+		return nil, errors.Wrap(err, "defaultencoder: encoding error")
 	}
 
-	msg.Data = b
-
-	return nil
+	return &natn.Msg{
+		Subject: subject,
+		Data:    buf.Bytes(),
+	}, err
 }