Moq - How to verify that a property value is set via the setter

Question

The following should work. Configure your mock object as:

var mock=new Mock<IContent>();
mock.SetupSet(content => content.IsCheckedOut=It.IsAny<bool>()).Verifiable();

And after the test code:

mock.VerifySet(content => content.IsCheckedOut=It.IsAny<bool>());

I haven't tested it anyway, so please tell me if it works for you.

EDIT. Indeed, this will not work since the setter for IsCheckedOut is false.

Anyway, now I see that you never set the value of IsCheckedOut at class construction time. It would be a good idea to add the following to the Content class:

public Content()
{
    IsCheckedOut=false;
}

Mock mockContect = new Mock<Cotent>(); 
mockContent.VerifySet(x => x.IsCheckedOut, Times.Once());

Will that do the trick? Not sure how the private setter comes in to play as havent tested that. but works for my public setter.

Got this from: http://www.codethinked.com/post/2009/03/10/Beginning-Mocking-With-Moq-3-Part-2.aspx

why don't you simply set up the content to be checked out to start with? Remember, you are only testing the behaviour of the CheckIn function.

[TestMethod]
public void CheckInSetsCheckedOutStatusToFalse()
{
    // arrange - create a checked out item
    Content c = new Content();
    c.CheckOut();

    // act - check it in
    c.CheckIn();

    // assert - IsCheckedOut should be set back to false
    Assert.AreEqual(false, c.IsCheckedOut);
}

Can I suggest that you might be thinking about this in the wrong way - generally you should be setting something up, performing an action and then checking the behaviour (result). In this case does it really matter that it wasn't set to false by the setter - what should matter is that it is false in after a given scenario has been exercised. If you take tests in isolation this might seem a bit odd, but for anything your tests will exist in sets.

The situation would be different if you were testing the interaction between two classes - then it would be fine to set up an expectation on the property setter - as the setting action is the interaction you're testing.

I'm not familiar with Moq as I use Rhino.Mocks - but I'm guessing there'll be something along the lines of mock.VerifySet(content => content.IsCheckedOut=It.IsEqual(true));