Can you store an 'It' matcher object as a variable, instead of defining it inline? (Moq)

Question

I'm mocking some objects using Moq, and some of them can have fairly lengthy parameter-collection request objects passed in as arguments.

For ease of re-use and style, I'd like to be able to store these requests, with specific arguments, for use in the mocking setup. For example:

mockedObject
  .Setup(mo =>
    mo.GetBobbins(It.Is<GetBobbinsRequest>
      (r.Parameter1 == value1 && [...] & r.ParameterN == valueN))
  .Returns(someBobbins);

becomes:

var request = It.Is<GetBobbinsRequest>
  (r.Parameter1 == value1 && [...] & r.ParameterN == valueN);
mockedObject
  .Setup(mo => mo.GetBobbins(request))
  .Returns(someBobbins);

But that doesn't seem to work. I also tried:

Func<GetBobbinsRequest> request = () => It.Is<GetBobbinsRequest>
  (r.Parameter1 == value1 && [...] & r.ParameterN == valueN);
mockedObject
  .Setup(mo => mo.GetBobbins(request()))
  .Returns(someBobbins);

But no joy there either. Is there any way I can save an Itstyle object as a variable? Or am I missing some other obvious way of handling this?

Answer 1

And... I've found the answer. It's Moq's Match (Class):

Creating a custom matcher is straightforward. You just need to create a method that returns a value from a call to Create with your matching condition and optional friendly render expression:

[Matcher]
public Order IsBigOrder()
{
    return Match<Order>.Create(
        o => o.GrandTotal >= 5000, 
        /* a friendly expression to render on failures */
        () => IsBigOrder());
}

This method can be used in any mock setup invocation:

mock.Setup(m => m.Submit(IsBigOrder()).Throws<UnauthorizedAccessException>();

http://www.nudoq.org/#!/Packages/Moq/Moq/Match(T)