patch: add statusCode to mocktr181's response payload

- add the missing `statusCode` field to mocktr181's response payload

internal/wrphandlers/mocktr181/handler.go

@@ -60,6 +60,7 @@ type Tr181Payload struct {
 	Command    string      `json:"command"`
 	Names      []string    `json:"names"`
 	Parameters []Parameter `json:"parameters"`
+	StatusCode int         `json:"statusCode"`
 }
 
 type Parameters struct {
@@ -157,8 +158,9 @@ func (h Handler) HandleWrp(msg wrp.Message) error {
 }
 
 func (h Handler) get(names []string) (int64, []byte, error) {
-	result := Tr181Payload{}
-	statusCode := int64(http.StatusOK)
+	result := Tr181Payload{
+		StatusCode: http.StatusOK,
+	}
 
 	for _, name := range names {
 		for _, mockParameter := range h.parameters {
@@ -178,26 +180,27 @@ func (h Handler) get(names []string) (int64, []byte, error) {
 				result.Parameters = append(result.Parameters, Parameter{
 					Message: fmt.Sprintf("Invalid parameter name: %s", mockParameter.Name),
 				})
-				statusCode = 520
+				result.StatusCode = 520
 			}
 		}
 	}
 
+	if len(result.Parameters) == 0 {
+		result.StatusCode = 520
+	}
+
 	payload, err := json.Marshal(result)
 	if err != nil {
 		return http.StatusInternalServerError, payload, errors.Join(ErrInvalidResponsePayload, err)
 	}
 
-	if len(result.Parameters) == 0 {
-		statusCode = int64(520)
-	}
-
-	return statusCode, payload, nil
+	return int64(result.StatusCode), payload, nil
 }
 
 func (h Handler) set(parameters []Parameter) (int64, []byte, error) {
-	statusCode := http.StatusAccepted
-	result := Tr181Payload{}
+	result := Tr181Payload{
+		StatusCode: http.StatusAccepted,
+	}
 	for _, parameter := range parameters {
 		for i := range h.parameters {
 			mockParameter := &h.parameters[i]
@@ -222,7 +225,7 @@ func (h Handler) set(parameters []Parameter) (int64, []byte, error) {
 					Name:    mockParameter.Name,
 					Message: "Parameter is not writable",
 				})
-				statusCode = 520
+				result.StatusCode = 520
 			}
 		}
 	}
@@ -232,7 +235,7 @@ func (h Handler) set(parameters []Parameter) (int64, []byte, error) {
 		return http.StatusInternalServerError, payload, errors.Join(ErrInvalidResponsePayload, err)
 	}
 
-	return int64(statusCode), payload, nil
+	return int64(result.StatusCode), payload, nil
 }
 
 func (h Handler) loadFile() ([]MockParameter, error) {