Question

我使用类似于本article

中描述的代码的Azure Redis和.Net Core 2的有效实现

我的问题是，如何从单元测试类实例化缓存的实例？我浏览了许多资源，却一无所获。

我需要能够创建一个实例来实例化诸如这样的类

    public CacheManager(IDataManager dataservices, IDistributedCache cache)
    {
        _cache = cache;
        _dataservices = dataservices;
    }

startup.cs中的代码使用ConfigureServices

            //Configure Redis Cache
        var redisconnection = Configuration.GetConnectionString("Redis");
        services.AddDistributedRedisCache(o => { o.Configuration = redisconnection; });

也许我需要向单元测试项目中添加一个包？怎么做？

Answer 1

您可以仅模拟接口以使其符合隔离单元测试的要求。

public void Test_CacheManager() {
    //Arrange
    IDataManager dataservices = new Mock<IDataManager>(); 
    IDistributedCache cache = new Mock<IDistributedCache>();
    var subject = new CacheManager(dataservices.Object, cache.Object);

    //Setup the mocks to behave as expected.

    //Act
    //...call the method under test

    //Assert
    //...assert the expected behavior
}

上面的示例使用Moq来演示如何模拟被测类的依赖项实例。

参考Moq Quickstart，以更好地了解如何使用模拟库。

如果要连接到实际的Redis连接，那么它将不再是单元测试，而是集成测试，这将需要完全不同的方法。

public void Test_CacheManager() {
    //Arrange

    IDataManager dataservices = new Mock<IDataManager>(); 
     //Setup the mocks to behave as expected.

    //Configure Redis Cache
    var services = new ServiceCollection();
    var redisconnection = "...";
    services.AddDistributedRedisCache(o => { o.Configuration = redisconnection; });
    var provider = services.BuildServiceProvider();
    IDistributedCache cache = provider.GetService<IDistributedCache>();

    var subject = new CacheManager(dataservices.Object, cache);

    //Act
    //...call the method under test

    //Assert
    //...assert the expected behavior
}

Answer 2

这是我在.net core 2.0和3.1中设法做到的方法。您需要使用MemoryDistributedCache。并通过您的服务构造函数。真实地说，您的服务通过de量注入使用IDistributedCache。 MemoryDistributedCache还实现IDistributedCache。

var mockedCacheSettings = new Mock<IOptions<CacheSettings>>();

        var options = new OptionsWrapper<MemoryDistributedCacheOptions>(new MemoryDistributedCacheOptions());
        _memoryDistributedCache = new MemoryDistributedCache(options);
        _distributedCacheService = new DistributedCacheService(_memoryDistributedCache, mockedCacheSettings.Object, NullLogger<DistributedCacheService>.Instance);

Answer 3

我已经使用Microsoft.Extensions.Caching.Distributed.MemoryDistributedCache类进行单元测试。这是IDistributedCache的内存实现。

这是我的单元测试代码的片段。

        [TestMethod]
        public void ExampleTestMethod()
        {
            var expectedData = new byte[] { 100, 200 };

            var opts = Options.Create<MemoryDistributedCacheOptions>(new MemoryDistributedCacheOptions());
            IDistributedCache cache1 = new MemoryDistributedCache(opts);
            cache1.Set("key1", expectedData);
            var cachedData = cache1.Get("key1");

            Assert.AreEqual(expectedData, cachedData);

           //Use the variable cache as an input to any class which expects IDistributedCache
        }

在我的示例中，我使用的是.NET Core 3.1，并且相关的NUGET软件包为

    <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="2.2.0" />
    <PackageReference Include="Microsoft.Extensions.Caching.StackExchangeRedis" Version="3.1.4" />

使用Azure Redis进行单元测试和IDistributedCache

3 个答案: