我正在尝试使用sqlmock对我的go代码进行单元测试。下面是我尝试测试的原始代码。

func enrollCourse(db *gorm.DB, user_id string ,course_id string) error {
    user := &usermodels.User{}
    ref := db.First(user, "uuid = ?", user_id)
    userPb := user.Protobuf()
    fmt.Printf("user name %+v", user.name)
    ....
}

这是我的单元测试

func TestEnrollCourse(t *testing.T){
    db, mock, err := sqlmock.New()
    if err != nil {
        t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
    }
    defer db.Close()

    rows := sqlmock.NewRows([]string{"user_id","user_name"}).
        AddRow(1, "John")
    mock.ExpectQuery(regexp.QuoteMeta(`SELECT * FROM "users" WHERE uuid = $1`)).WithArgs("user-fd3746c8-d32f-4fb8-8f6a-b6d72dcf2969").WillReturnRows(rows)
    
    gdb, err := gorm.Open(postgres.New(postgres.Config{
                       Conn: db,
               }), &gorm.Config{})

    enrollCourse(gdb, "user-fd3746c8-d32f-4fb8-8f6a-b6d72dcf2969", "english_course")
    ....
}

我希望fmt.Printf（“user name %+v”，user.name）输出用户名，但它为空。如何正确地将protobuf对象传递给addRow？