如何模拟 Azure 队列存储以进行单元测试？答案

【问题标题】：How to mock Azure Queue storage for unit test?如何模拟 Azure 队列存储以进行单元测试？
【发布时间】：2020-11-27 14:39:47
【问题描述】：

我想模拟 QueueMessage 进行单元测试，但我找不到任何要模拟的库

    public  async Task<QueueMessage[]> ReceiveMessagesAsync(QueueClient queue)
       {
     
        QueueProperties properties = queue.GetProperties();

        // Retrieve the cached approximate message count.
        int cachedMessagesCount = properties.ApproximateMessagesCount;
        QueueMessage[] queueMessages =new QueueMessage[cachedMessagesCount];

        int num = cachedMessagesCount / 32;

        for (int i = 0; i < num + 1; i++)
        {
         var  messages = await queue.ReceiveMessagesAsync(maxMessages: 32);
         messages.Value.CopyTo(queueMessages,i*32);
        }
        return queueMessages;
    }

【问题讨论】：

模拟 EAI 系统 的各个方面有什么意义？消息只是信封。你想要有效载荷。测试有效载荷的处理程序不是更好吗？ well-written system 的业务逻辑应该与任何 EAI 系统解耦
@MickyD 感谢您的评论！你真的明白了，我通过返回 QueueMessage.MessageText 而不是对象本身解决了这个不需要的问题。绝对正确的观点，需要考虑！

标签： c# azure azure-storage xunit

【解决方案1】：

队列模型的构造函数是内部的，但您可以使用QueuesModelFactory 创建对象，它提供了用于模拟的实用程序。

QueueMessage queueMsg = QueuesModelFactory.QueueMessage(
    messageId: "id2", 
    popReceipt: "pr2", 
    body: JsonConvert.SerializeObject("Test"), 
    dequeueCount: 1, 
    insertedOn: DateTimeOffset.UtcNow);

 var metadata = new Dictionary<string, string> { { "key", "value" }, };
 int messageCount = 5;
 QueueProperties queueProp = QueuesModelFactory.QueueProperties(metadata, messageCount);

【讨论】：

【解决方案2】：

Mocking lib 的选择将是一个固执己见的答案。有几个可用的模拟框架。最受欢迎的之一是Moq。

使用最小起订量，您的上述代码的示例测试如下所示。请注意，如您所见，模拟存储库是一项有点乏味的任务。

        [Test]
        public async Task ReceiveMessagesAsync_StateUnderTest_ExpectedBehavior()
        {
            // Arrange
            var queueClientHelper = new QueueClientHelper();
            var queueMock = new Mock<QueueClient>();
            var mockPropertiesResponse = new Mock<Response<QueueProperties>>();
            var properties = new QueueProperties();
            properties.GetType().GetProperty(nameof(properties.ApproximateMessagesCount), BindingFlags.Public | BindingFlags.Instance).SetValue(properties, 64); // little hack since ApproximateMessagesCount has internal setter
            mockPropertiesResponse.SetupGet(r => r.Value).Returns(properties);
            queueMock.Setup(q => q.GetProperties(It.IsAny<CancellationToken>())).Returns(mockPropertiesResponse.Object);
            var mockMessageReponse = new Mock<Response<QueueMessage[]>>();
            mockMessageReponse.SetupGet(m => m.Value).Returns(new QueueMessage[32]);
            queueMock.Setup(q => q.ReceiveMessagesAsync(It.IsAny<int?>(), It.IsAny<TimeSpan?>(), It.IsAny<CancellationToken>())).ReturnsAsync(mockMessageReponse.Object);

            // Act
            var result = await queueClientHelper.ReceiveMessagesAsync(queueMock.Object);

            // Assert
            Assert.AreEqual(64, result.Length);
            // verify mocks as required
        }

【讨论】：

非常感谢！天哪

【解决方案3】：

尝试模拟 queueClient 的响应，这将验证 sendMessageAsync 响应

[Fact]
    public async Task SendMessage_ShouldReturnSuccess()
    {
        var receipt = QueuesModelFactory.SendReceipt("1", DateTimeOffset.Now, DateTimeOffset.Now.AddDays(2), "pop", DateTimeOffset.Now.AddDays(1));
        var res = Response.FromValue<SendReceipt>(receipt, null);
        var queueClientmock = new Mock<QueueClient>();
        queueClientmock.Setup(q => q.SendMessageAsync(It.IsAny<string>())).Returns(Task.FromResult(res));
        var sqmock = new Mock<IStorageQueueProvider>();
        sqmock.Setup(s => s.GetStorageQueueClient()).Returns(Task.FromResult(queueClientmock.Object)).Verifiable();
        var storageQueueRepository = new StorageQueueRepository(sqmock.Object, DummyLogger);
        var result = await storageQueueRepository.SendMessage("test message");
        result.StatusCode.Should().Be(HttpStatusCode.OK);
    }

【讨论】：