Different return values the first and second time with Moq

With the latest version of Moq(4.2.1312.1622), you can setup a sequence of events using SetupSequence. Here’s an example:

_mockClient.SetupSequence(m => m.Connect(It.IsAny<String>(), It.IsAny<int>(), It.IsAny<int>()))
        .Throws(new SocketException())
        .Throws(new SocketException())
        .Returns(true)
        .Throws(new SocketException())
        .Returns(true);

Calling connect will only be successful on the third and fifth attempt otherwise an exception will be thrown.

So for your example it would just be something like:

repository.SetupSequence(x => x.GetPageByUrl<IPageModel>(virtualUrl))
.Returns(null)
.Returns(pageModel.Object);