Code snippets for "Mocking expensive template methods" post

s1.cs

    public abstract class Command
    {
        private readonly List<string> errorMessages = new List<string>();
 
        public void Execute()
        {
            try
            {
                CheckAuthorization();
                CheckErrorMessages();
                ValidateInput();
                CheckErrorMessages();
                ProcessInput();
                CheckErrorMessages();
            }
            catch (Exception e)
            {
                Logger.Log(e);
                // do something clever that developers supposedly don't think of
                // ...
            }
        }
 
        protected virtual void CheckAuthorization() { }
        protected virtual void ValidateInput() { }
        protected virtual void ProcessInput() {}
 
        protected void AddErrorMessage(string errorMessage)
        {
            errorMessages.Add(errorMessage);   
        }
 
        private void CheckErrorMessages()
        {
            if (errorMessages.Count > 0)
            {
                // throw some kind of exception which contains all of the messages
            }
        }
    }

s2.cs

    public class DeleteCustomerCommand : Command
    {
        private Customer customer;
        private CustomerDataLayerComponent customerDAL;
 
        public void Execute(Customer customer)
        {
            this.customer = customer;
            customerDAL = new CustomerDataLayerComponent();
            Execute();
        }
 
        protected override void CheckAuthorization()
        {
            if (!AuthorizationManager.IsAllowedToAccess<DeleteCustomerCommand>())
            {
                AddErrorMessage("sorry buddy, no access");
            }
        }
 
        protected override void ValidateInput()
        {
            if (customerDAL.GetOutstandingOrderCount(customer.Id) > 0)
            {
                AddErrorMessage("Customer can't be deleted when there are outstanding orders");
            }
        }
 
        protected override void ProcessInput()
        {
            try
            {
                customerDAL.Delete(customer);
            }
            catch (Exception e)
            {
                AddErrorMessage(e.Message);
            }
        }
    }

s3.cs

            customerDAL = new CustomerDataLayerComponent();

s4.cs

            if (!AuthorizationManager.IsAllowedToAccess<DeleteCustomerCommand>())

s5.cs

        [Test]
        public void AddsErrorMessageWhenUserDoesntHaveAccessToThisCommand()
        {
            var mocks = new MockRepository();
            var command = mocks.PartialMock<DeleteCustomerCommand>();
 
            PrepareAuthorizationManagerToDenyAccess();
            command.Stub(c => c.ValidateInput()).Do(new Action(EmptyMethodThatDoesntDoAnyting));
            command.Stub(c => c.ProcessInput()).Do(new Action(EmptyMethodThatDoesntDoAnyting));
            mocks.ReplayAll();
 
            AssertThrows<Exception>("sorry buddy, no access", () => command.Execute(new Customer()));
        }

s6.cs

        [Test]
        public void AddsErrorMessageWhenCustomerHasOutstandingOrders()
        {
            var mocks = new MockRepository();
            var command = mocks.PartialMock<DeleteCustomerCommand>();
            var customer = new Customer();
 
            CreateOutstandingOrderFor(customer);
            command.Stub(c => c.CheckAuthorization()).Do(new Action(EmptyMethodThatDoesntDoAnyting));
            command.Stub(c => c.ProcessInput()).Do(new Action(EmptyMethodThatDoesntDoAnyting));
            mocks.ReplayAll();
 
            AssertThrows<Exception>("Customer can't be deleted when there are outstanding orders",
                () => command.Execute(customer));
        }