public void CanCall_BuildBuster_IfValue_IsNotNullOrEmpty() { const string currentMessage = "Breakers: Bob, Mary"; DoConvert(currentMessage); // this is all we want to know - the fact that the BuildBuster "is called" (with the correct arguments) // (the BuildBuster is tested elsewhere - ie DRY) _buildBuster.ShouldHaveBeenCalled(b => b.FindBreaker(currentMessage)); }