为 Azure table 存储模拟 CloudStorageAccount 和 CloudTable

Question

所以我正在尝试测试 Azure Table 存储和模拟我所依赖的东西。我的 class 的结构是在构造函数中建立连接，即我创建了一个 CloudStorageAccount 的新实例，在其中我创建了一个 StorageCredentials 的实例，该实例具有 storageName 和 storageKey。之后，我创建了一个 CloudTable 的实例，我在代码中进一步使用它来执行 CRUD 操作。我的 class 看起来如下：

public class AzureTableStorageService : ITableStorage
{
        private const string _records = "myTable";
        private CloudStorageAccount _storageAccount;
        private CloudTable _table;

        public AzureTableStorageService()
        {
            _storageAccount = new CloudStorageAccount(new StorageCredentials(
                 ConfigurationManager.azureTableStorageName, ConfigurationManager.azureTableStorageKey), true);
            _table = _storageAccount.CreateCloudTableClient().GetTableReference(_records);
            _table.CreateIfNotExistsAsync();
        }

        //...
        //Other methods here
}

_table 在整个 class 中被重复用于不同的目的。我的目标是模拟它，但由于它是虚拟的并且没有实现任何接口，所以我无法提出一个简单的 Mock 解决方案，例如：

_storageAccount = new Mock<CloudStorageAccount>(new Mock<StorageCredentials>(("dummy", "dummy"), true));
_table  = new Mock<CloudTable>(_storageAccount.Object.CreateCloudTableClient().GetTableReference(_records));

因此，当我尝试以这种方式构建我的单元测试时，我得到： Type to mock must be an interface or an abstract or non-sealed class.

我的目标是完成类似的事情：

_table.Setup(x => x.DoSomething()).ReturnsAsync("My desired result");

非常感谢任何想法！

Answer 1

我也在为绑定到 Azure Table 存储的 Azure 函数实施单元测试而苦苦挣扎。我终于使用派生的 CloudTable class 让它工作了，我可以在其中覆盖我使用的方法和 return 固定结果。

/// <summary>
/// Mock class for CloudTable object
/// </summary>
public class MockCloudTable : CloudTable
{

    public MockCloudTable(Uri tableAddress) : base(tableAddress)
    { }

    public MockCloudTable(StorageUri tableAddress, StorageCredentials credentials) : base(tableAddress, credentials)
    { }

    public MockCloudTable(Uri tableAbsoluteUri, StorageCredentials credentials) : base(tableAbsoluteUri, credentials)
    { }

    public async override Task<TableResult> ExecuteAsync(TableOperation operation)
    {
        return await Task.FromResult(new TableResult
        {
            Result = new ScreenSettingEntity() { Settings = "" },
            HttpStatusCode = 200
        });
    }
}

我通过传递存储模拟器用于本地存储的配置字符串实例化了模拟 class（参见 https://docs.microsoft.com/en-us/azure/storage/common/storage-configure-connection-string）。

var mockTable = new MockCloudTable(new Uri("http://127.0.0.1:10002/devstoreaccount1/screenSettings"));

在此示例中 'screenSettings' 是 table 的名称。

现在可以将模拟 class 从单元测试传递到 Azure 函数。

也许这就是您要找的东西？

Answer 2

要在这里添加答案，因为您的目标是使用模拟框架，只需设置一个从 CloudTable 继承的对象并提供默认构造函数，就可以让您模拟继承的对象本身并控制它的内容returns:

public class CloudTableMock : CloudTable
{
    public CloudTableMock() : base(new Uri("http://127.0.0.1:10002/devstoreaccount1/screenSettings"))
    {
    }
}

那么这只是一个创建模拟的案例。我正在使用 NSubstitute，所以我这样做了：

_mockTable = Substitute.For<CloudTableMock>();

但我猜最小起订量会允许：

_mockTableRef = new Mock<CloudTable>();
_mockTableRef.Setup(x => x.DoSomething()).ReturnsAsync("My desired result");
_mockTable = _mockTableRef.Object;

（我的最小起订量有点生疏，所以我猜上面的语法不太正确）

Answer 3

这是我的实现：

 public class StorageServiceTest
{
   IStorageService _storageService;
    Mock<CloudStorageAccount> _storageAccount;
    [SetUp]
    public void Setup()
    {
        var c = new StorageCredentials("dummyStorageAccountName","DummyKey");
       _storageAccount = new Mock<CloudStorageAccount>(c, true);
        _storageService = new StorageService(_storageAccount.Object);
    }

    [Test]
    [TestCase("ax0-1s", "random-1")]
    public void get_content_unauthorized(string containerName,string blobName)
    {
        //Arrange
        string expectOutputText = "Something on the expected blob";
        Uri uri = new Uri("https://somethig.com//");
        var blobClientMock = new Mock<CloudBlobClient>(uri);
        _storageAccount.Setup(a => a.CreateCloudBlobClient()).Returns(blobClientMock.Object);

        var cloudBlobContainerMock = new Mock<CloudBlobContainer>(uri);
        blobClientMock.Setup(a => a.GetContainerReference(containerName)).Returns(cloudBlobContainerMock.Object);

        var cloudBlockBlobMock = new Mock<CloudBlockBlob>(uri);
        cloudBlobContainerMock.Setup(a => a.GetBlockBlobReference(blobName)).Returns(cloudBlockBlobMock.Object);

        cloudBlockBlobMock.Setup(a => a.DownloadTextAsync()).Returns(Task.FromResult(expectOutputText));

        //Act
       var actual = _storageService.DownloadBlobAsString(containerName, blobName);

        //Assert
        Assert.IsNotNull(actual);
        Assert.IsFalse(string.IsNullOrWhiteSpace(actual.Result));
        Assert.AreEqual(actual.Result, expectOutputText);
    }
}

服务class实施：

 Task<string> IStorageService.DownloadBlobAsString(string containerName, string blobName)
    {
        var blobClient = this.StorageAccountClient.CreateCloudBlobClient();

        var blobContainer = blobClient.GetContainerReference(containerName);

        var blobReference = blobContainer.GetBlockBlobReference(blobName);

        var blobContentAsString = blobReference.DownloadTextAsync();

        return blobContentAsString;
    }

Answer 4

我遇到了与所选答案相同的场景，涉及具有 table 绑定的 Azure 函数。使用模拟 CloudTable 有一些限制，尤其是当 System.Linq 与 CreateQuery<T> 一起使用时，因为这些是 IQueryable.

上的扩展方法

更好的方法是使用 HttpMessageHandler 模拟，例如 RichardSzalay.MockHttp 和 TableClientConfiguration.RestExecutorConfiguration.DelegatingHandler，然后将 json 您期望来自 table.

的响应

public class Azure_Function_Test_With_Table_Binding
{
    [Fact]
    public void Should_be_able_to_stub_out_a_CloudTable()
    {
        var storageAccount = StorageAccount.NewFromConnectionString("UseDevelopmentStorage=true");
        var client = storageAccount.CreateCloudTableClient();

        var mockedRequest = new MockHttpMessageHandler()
            .When("http://127.0.0.1:10002/devstoreaccount1/pizzas*")
            .Respond("application/json", 
            @"{
                ""value"": [
                    {
                        ""Name"": ""Pepperoni"",
                        ""Price"": 9.99
                    }
                ]
            }");

        client.TableClientConfiguration.RestExecutorConfiguration.DelegatingHandler = new MockedRequestAdapter(mockedRequest);
        var table = client.GetTableReference("pizzas");

        var request = new DefaultHttpContext().Request;
        request.Query = new QueryCollection(new Dictionary<string, StringValues> { { "Pizza", new StringValues("Pepperoni") } });

        var result = PizzaStore.Run(request, table, null);

        Assert.IsType<OkObjectResult>(result);
    }
}

public class MockedRequestAdapter : DelegatingHandler
{
    private readonly MockedRequest _mockedRequest;

    public MockedRequestAdapter(MockedRequest mockedRequest) : base()
    {
        _mockedRequest = mockedRequest;
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        return await _mockedRequest.SendAsync(new HttpRequestMessage(request.Method, request.RequestUri), cancellationToken);
    }
}

public static class PizzaStore
{
    [FunctionName("PizzaStore")]
    public static IActionResult Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
        [Table("pizzas", Connection = "AzureWebJobsStorage")] CloudTable cloud,
        ILogger log)
    {
        if (req.Query.TryGetValue("Pizza", out var value))
        {
            var pizza = cloud.CreateQuery<Pizza>().Where(p => p.Name == value.ToString()).SingleOrDefault();

            return new OkObjectResult(new { Pizza = pizza.Name, Price = pizza.Price });
        }

        return new NotFoundResult();
    }
}

public class Pizza : TableEntity
{
    public string Name { get; set; }
    public double Price { get; set; }
}

为 Azure table 存储模拟 CloudStorageAccount 和 CloudTable

Mocking CloudStorageAccount and CloudTable for Azure table storage

c#

unit-testing

mocking

azure

azure-table-storage