public void UpdateBankAccount() { var context = serviceProvider.GetRequiredService <DataContext>(); var controller = new BankAccountsController(context); context.BankAccount.Add(bankAccount1); context.SaveChanges(); //The entity is not being tracked by the context context.Entry(bankAccount1).State = EntityState.Detached; BankAccount bankAccount3 = new BankAccount { Id = "18379133", BankName = "First Bank", Balance = 33.98, AccountType = "BUSINESS", UserId = 2 }; var updateResult = controller.PutBankAccount(Int32.Parse(bankAccount3.Id), bankAccount3).Result; Assert.IsType <OkResult>(updateResult); }