public void TestClientControllerDoesNotAddClientWhenClientExists() { clientRepoMocked.Setup(x => x.FindByUsername("ExistingClient")).Returns(() => new Client()); ClientController controller = new ClientController(clientRepoMocked.Object); ClientViewModel client = new ClientViewModel() { Username = "******", Password = "******" }; controller.AddOrEdit(client); Assert.AreEqual(nrCurrentClienti, nrInitialClienti); }