public void When_Clearing_The_PostBox_On_The_Command_Processor() { _fakeMessageStore.Add(_message); _commandProcessor.ClearPostBox(_message.Id); //_should_send_a_message_via_the_messaging_gateway _fakeMessageProducer.MessageWasSent.Should().BeTrue(); var sentMessage = _fakeMessageProducer.SentMessages.FirstOrDefault(); sentMessage.Should().NotBe(null); sentMessage.Id.Should().Be(_message.Id); sentMessage.Header.Topic.Should().Be(_message.Header.Topic); sentMessage.Body.Value.Should().Be(_message.Body.Value); }