public void Should_on_received_deserialize_and_fire_message() { var message = new ResponseMessage(); MessageSerializer.Stub(s => s.Deserialize(Arg <byte[]> .Is.Anything)).Return(message); Subject.OnReceive(SerializedData); MessageSerializer.AssertWasCalled(s => s.Deserialize(SerializedData)); Assert.That(Subject.MessageReceived, Is.EqualTo(message)); }