Moq - Ordered Setups (Expectations)

Question

Hi All,

I am fairly new to Moq and cant work out how I am to order setups. I have the following code:

_orderRepository.Setup(r => r.Update(It.Is<Order>(a => ((int)a.OrderStatusReference.EntityKey.EntityKeyValues[0].Value) == 2)))
                        .Throws(exception)
                        .AtMost(5);

I want this to be executed 5 times (its retry logic, if the update fails). After the 5th time I want to setup and expect that it is successful (An exception is not thrown):

_orderRepository.Setup(r => r.Update(It.Is<Order>(a => ((int)a.OrderStatusReference.EntityKey.EntityKeyValues[0].Value) == 2))).AtMostOnce();

Unfortinatly it continues to use the 1st code sample, and never successfully updates.

If I were not using the Throws method, then I can use the Callback method, however its not available after a throw :(.

If there a way or is this a limitation of Moq?

Answer 1

Moq doesn't support ordering of expectations. See here for more details.

Although I currently use Moq, I used to use RhinoMocks before, and it certainly has some features that I occasionally miss with Moq - ordered expectations being one of them.

Answer 2

Bah... there are ways!

You can use a Queue to return a list of return values (strategy explained pretty well here: http://haacked.com/archive/2009/09/29/moq-sequences.aspx).

Here's a sample from that blog:

If you want this to work (which it doesn't):

reader.Setup(r => r.Read()).Returns(true);
reader.Setup(r => r.Read()).Returns(true);
reader.Setup(r => r.Read()).Returns(false);

Just do this instead:

Queue listOfOperations = new Queue<bool>(new bool[] { true, true, false });

reader.Setup(r => r.Read())
  .Returns(() => listOfOperations.Dequeue());

Each time Read() is called a new value from your Queue will be used.

Enjoy!