public void Create_new_computer() { ComputersController computersController = new ComputersController(); int numberOfComputers = computersController.All().Count; _managementController.AddComputer(new AddComputerDto { Name = "TestComputer", Description = "New computer", Price = 1500, ImageFilename = "test.png" }); var allComputers = computersController.All(); int currentNumberOfComputers = allComputers.Count; Assert.AreEqual(numberOfComputers + 1, currentNumberOfComputers); Assert.IsNotNull(allComputers.First(comp => comp.Name == "TestComputer")); }