public void OrderSave() { var options = new DbContextOptionsBuilder <PersistentContext>() .UseInMemoryDatabase(databaseName: "order_test") .Options; // Run the test against one instance of the context var context = new PersistentContext(options); var orderRepository = new OrderRepository(context); var queueService = new QueueService(); OrderService orderService = new OrderService(orderRepository, queueService); var order = new Order() { Id = 32322, Quantity = 2, Side = "buy", Symbol = "PETR4", Price = 11 }; queueService.AddOrderInQueue(order); }