I've created a unit test that tests interactions on my ViewModel class in a Silverlight application. To be able to do this test, I'm mocking the service interface, injected to the ViewModel. I'm using Moq framework to do the mocking.

to be able to verify bounded object in the ViewModel is converted properly, I've used a callback:

[Test]
public void SaveProposal_Will_Map_Proposal_To_WebService_Parameter()
{
 var vm = CreateNewCampaignViewModel();
 var proposal = CreateNewProposal(1, "New Proposal");

 Services.Setup(x => x.SaveProposalAsync(It.IsAny<saveProposalParam>())).Callback((saveProposalParam p) =>
 {
  Assert.That(p.plainProposal, Is.Not.Null);
  Assert.That(p.plainProposal.POrderItem.orderItemId, Is.EqualTo(1));
  Assert.That(p.plainProposal.POrderItem.orderName, Is.EqualTo("New Proposal"));
 });

 proposal.State = ObjectStates.Added;
 vm.CurrentProposal = proposal;
 vm.Save();
}

It is working fine, but if you've noticed, using this mechanism the Assert and Act part of the unit test have switched their parts (Assert comes before Acting). Is there a better way to do this, while preserving correct AAA order?