配置 MassTransit 以使用 WebApplicationFactory<Startup> 进行测试

Question

我有一个 ASP.NET 核心网络应用程序和测试设置，使用 WebApplicationFactory 来测试我的控制器操作。我之前使用过 RawRabbit，我很容易模拟 IBusClient 并将其作为单例添加到 DI 容器中。在 WebApplicationFactory<TStartup>.CreateWebHostBuilder() 中，我调用此扩展方法来添加我的模拟 IBusClient 实例，如下所示；

/// <summary>
/// Configures the service bus.
/// </summary>
/// <param name="webHostBuilder">The web host builder.</param>
/// <returns>A web host builder.</returns>
public static IWebHostBuilder ConfigureTestServiceBus(this IWebHostBuilder webHostBuilder)
{
    webHostBuilder.ConfigureTestServices(services =>
    {
        services.AddSingleton<IBusClient, MY_MOCK_INSTANCE>
    });

    return webHostBuilder;
}

但是现在 RawRabbit 中存在差距，这让我决定转向 MassTransit。但是，我想知道是否已经有更好的方法将 IBus 注册到我的容器中而无需在我的测试中模拟它。不确定 InMemoryTestFixture、BusTestFixture 或 BusTestHarness 是否可以解决我的问题。不确定如何一起使用它们以及它们的作用。

顺便说一句，在我的 ASP.NET 核心应用程序中，我有一个可重用的扩展方法设置，如下面的代码，用于在启动时将我连接到 RabbitMQ。

/// <summary>
/// Adds the service bus.
/// </summary>
/// <param name="services">The services.</param>
/// <param name="configurator">The configurator.</param>
/// <returns>A service collection.</returns>
public static IServiceCollection AddServiceBus(this IServiceCollection services, Action<IServiceCollectionConfigurator> configurator)
{
    var rabbitMqConfig = new ConfigurationBuilder()
        .AddJsonFile("/app/configs/service-bus.json", optional: false, reloadOnChange: true)
        .Build();

    // Setup DI for MassTransit.
    services.AddMassTransit(x =>
    {
        configurator(x);

        // Get the json configuration and use it to setup connection to RabbitMQ.
        var rabbitMQConfig = rabbitMqConfig.GetSection(ServiceBusOptionsKey).Get<RabbitMQOptions>();

        // Add bus to the container.
        x.AddBus(provider => Bus.Factory.CreateUsingRabbitMq(cfg =>
        {
            cfg.Host(
                new Uri(rabbitMQConfig.Host),
                hostConfig =>
                {
                    hostConfig.Username(rabbitMQConfig.Username);
                    hostConfig.Password(rabbitMQConfig.Password);
                    hostConfig.Heartbeat(rabbitMQConfig.Heartbeat);
                });

            cfg.ConfigureEndpoints(provider);

            // Add Serilog logging.
            cfg.UseSerilog();
        }));
    });

    // Add the hosted service that starts and stops the BusControl.
    services.AddSingleton<IMessageDataRepository, EncryptedMessageDataRepository>();
    services.AddSingleton<IEndpointNameFormatter, EndpointNameFormatter>();
    services.AddSingleton<IBus>(provider => provider.GetRequiredService<IBusControl>());
    services.AddSingleton<IHostedService, BusHostedService>();

    return services;
}

Answer 1

你最好的选择是使用 InMemoryTestHarness，这样你就可以确保你的消息契约可以序列化，你的消费者配置正确，并且一切都按预期工作。虽然有些人可能将其称为集成测试，但它实际上只是在进行适当的测试。而且它非常快，因为它都在内存中。

你可以看到一个单元测试here，但下面也显示了一个简短的例子。

[TestFixture]
public class When_a_consumer_is_being_tested
{
    InMemoryTestHarness _harness;
    ConsumerTestHarness<Testsumer> _consumer;

    [OneTimeSetUp]
    public async Task A_consumer_is_being_tested()
    {
        _harness = new InMemoryTestHarness();
        _consumer = _harness.Consumer<Testsumer>();

        await _harness.Start();

        await _harness.InputQueueSendEndpoint.Send(new A());
    }

    [OneTimeTearDown]
    public async Task Teardown()
    {
        await _harness.Stop();
    }

    [Test]
    public void Should_have_called_the_consumer_method()
    {
        _consumer.Consumed.Select<A>().Any().ShouldBe(true);
    }


    class Testsumer :
        IConsumer<A>
    {
        public async Task Consume(ConsumeContext<A> context)
        {
            await context.RespondAsync(new B());
        }
    }


    class A
    {
    }


    class B
    {
    }
}

Answer 2

我最终像这样在我的 WebApplicationFactory 中创建了一个方法；

    public void ConfigureTestServiceBus(Action<IServiceCollectionConfigurator> configurator)
    {
        this._configurator = configurator;
    }

让我能够从派生集成 class 构造函数中注册测试处理程序；

    public Intg_GetCustomers(WebApplicationTestFactory<Startup> factory)
        : base(factory)
    {
        factory.ConfigureTestServiceBus(c =>
        {
            c.AddConsumer<TestGetProductConsumer>();
        });
    }

当我调用我的扩展方法以添加 MassTransit 的 InMemory 实例时，将使用此配置器

public static IWebHostBuilder ConfigureTestServiceBus(this IWebHostBuilder webHostBuilder, Action<IServiceCollectionConfigurator> configurator)
{
    return webHostBuilder
        .ConfigureTestServices(services =>
        {
            // UseInMemoryServiceBus DI for MassTransit.
            services.AddMassTransit(c =>
            {
                configurator?.Invoke(c);

                // Add bus to the container.
                c.AddBus(provider =>
                {
                    var control = Bus.Factory.CreateUsingInMemory(cfg =>
                    {
                        cfg.ConfigureEndpoints(provider);
                    });

                    control.Start();

                    return control;
                });
            });

            services.AddSingleton<IMessageDataRepository, InMemoryMessageDataRepository>();
        });
}

Answer 3

通过从 MassTransit 命名空间中删除服务，可以将启动期间定义的 MassTransit 配置替换为具有自定义 WebApplicationFactory 的新配置，例如

public class CustomWebApplicationFactory : WebApplicationFactory<Startup>  
{   
    protected override void ConfigureWebHost(IWebHostBuilder builder) 
    {
      builder.ConfigureServices(services => 
      {
          var massTransitHostedService = services.FirstOrDefault(d => d.ServiceType == typeof(IHostedService) &&
                    d.ImplementationFactory != null &&
                    d.ImplementationFactory.Method.ReturnType == typeof(MassTransitHostedService)
                );
           services.Remove(massTransitHostedService);
           var descriptors = services.Where(d => 
                  d.ServiceType.Namespace.Contains("MassTransit",StringComparison.OrdinalIgnoreCase))
                                     .ToList();
         foreach (var d in descriptors) 
         {
           services.Remove(d);
         }     

         services.AddMassTransitInMemoryTestHarness(x =>
         {
           //add your consumers (again)
         });
      });
   }
}

然后你的测试看起来像

public class TestClass : IClassFixture<CustomApplicationFactory> 
 {
    private readonly CustomApplicationFactoryfactory;

    public TestClass(CustomApplicationFactoryfactory)
    {
      this.factory = factory;
    }

    [Fact]    
    public async Task TestName()
    {   
      CancellationToken cancellationToken = new CancellationTokenSource(5000).Token;  
      var harness = factory.Services.GetRequiredService<InMemoryTestHarness>();
      await harness.Start();

      var bus = factory.Services.GetRequiredService<IBusControl>();
      try
      {
        await bus.Publish<MessageClass>(...some message...);      
        
        bool consumed = await harness.Consumed.Any<MessageClass>(cancellationToken);
        //do your asserts
      }
      finally
      {
        await harness.Stop();
      }
    }   
  }

Answer 4

在我的例子中（我只在所有地方注入 IPublishEndpoint 接口）我只是简单地在 ConfigureTestServices 方法中注册了另一个 IPublishEndpoint，如下所示：

[TestClass]
public class TastyTests
{
    private readonly WebApplicationFactory<Startup> factory;
    private readonly InMemoryTestHarness harness = new();

    public TastyTests()
    {
        factory = new WebApplicationFactory<Startup>().WithWebHostBuilder(builder =>
        {
            builder.ConfigureTestServices(services =>
            {
                services.AddSingleton<IPublishEndpoint>(serviceProvider =>
                {
                    return harness.Bus;
                });
            });
        });
    }

    [TestMethod]
    public async Task Test()
    {
        await harness.Start();
        try
        {
            var client = factory.CreateClient();
            const string url = "/endpoint-that-publish-message";

            var content = new StringContent("", Encoding.UTF8, "application/json");
            var response = await client.PostAsync(url, content);
            (await harness.Published.Any<IMessage>()).Should().BeTrue();
        }
        finally
        {
            await harness.Stop();
        }
    }
}

配置 MassTransit 以使用 WebApplicationFactory<Startup> 进行测试

Configure MassTransit for testing with WebApplicationFactory<Startup>

integration-testing

masstransit

rabbitmq

.net-core

rawrabbit