单元测试 MassTransit 时未调用消费者

Question

我正在尝试使用 MassTransit 编写单元测试。在线查看时，我发现访问总线的最佳方法是使用InMemoryTestHarness 创建它。我添加了我的消费者和 PublishObserver 以获得结果行为。

在下面的示例中，我将TestRequest 消息发送到总线，然后我的消费者读取请求并将TestResponse 消息放回总线上。最后，观察者得到响应。

我不知道问题是否与我缺少的某些配置有关，或者是否有一些我没有等待的任务，但请求消息甚至从未到达消费者。

我错过了什么？

测试

[TestMethod]
public void RequestResponseBusTest()
{
    var harness = new InMemoryTestHarness();

    var consumer = new TestConsumer();
    harness.OnConfigureInMemoryBus += c =>
    {
        c.ReceiveEndpoint("testqueue", e =>
            e.Consumer(() => consumer));
    };

    var observer = new TestPublishObserver();
    harness.OnConnectObservers += c =>
    {
        c.ConnectPublishObserver(observer);
    };

    harness.Start().Wait();
    var bus = harness.Bus;

    bus.Publish(new TestRequest() { X = 99 }).Wait();

    Assert.AreEqual(1, consumer.ConsumedMessages.Count, "consumed");
    Assert.AreEqual(1, observer.PublishedRequests.Count, "requests");
    Assert.AreEqual(1, observer.PublishedResponses.Count, "responses");

}

和支持类

[Serializable]
public class TestRequest
{
    public int X { get; set; }
}

[Serializable]
public class TestResponse
{
    public int Y { get; set; }
}

public class TestConsumer : IConsumer<TestRequest>
{
    public List<TestRequest> ConsumedMessages { get; } = new List<TestRequest>();

    public Task Consume(ConsumeContext<TestRequest> context)
    {
        ConsumedMessages.Add(context.Message);
        context.Publish(new TestResponse() { Y = 123 }).Wait();
        return Task.CompletedTask;
    }
}

private class TestPublishObserver : IPublishObserver
{
    public List<TestRequest> PublishedRequests { get; } = new List<TestRequest>();
    public List<TestResponse> PublishedResponses { get; } = new List<TestResponse>();

    public Task PrePublish<T>(PublishContext<T> context) where T : class
    {
        return Task.CompletedTask;
    }

    public Task PostPublish<T>(PublishContext<T> context) where T : class
    {
        var msg = context.Message;

        if (msg is TestRequest)
            PublishedRequests.Add((TestRequest)(object)msg);

        if (msg is TestResponse)
            PublishedResponses.Add((TestResponse)(object)msg);

        return Task.CompletedTask;
    }

    public Task PublishFault<T>(PublishContext<T> context, Exception exception) where T : class
    {
        return Task.CompletedTask;
    }
}

Answer 1

你需要在 bus.Publish(new TestRequest() { X = 99 }).Wait(); 之后添加 Thread.Sleep(2000) bus.Publish 不保证消息传递。当你调用 Wait() 方法时，你只是等待它被发送，而不是被处理

或者！！！

[TestMethod]
public void RequestResponseBusTest()
{
    var harness = new InMemoryTestHarness();

    var consumer = new TestConsumer();
    harness.OnConfigureInMemoryBus += c =>
    {
        c.ReceiveEndpoint("testqueue", e =>
            e.Consumer(() => consumer));
    };

    var observer = new TestPublishObserver();
    harness.OnConnectObservers += c =>
    {
        c.ConnectPublishObserver(observer);
    };

    harness.Start().Wait();
    var bus = harness.Bus;

    bus.Publish(new TestRequest() { X = 99 }).Wait();

    //add this line
    var receivedMessage = harness.Consumed.Select<TestRequest>().FirstOrDefault();

    Assert.AreEqual(1, consumer.ConsumedMessages.Count, "consumed");
    Assert.AreEqual(1, observer.PublishedRequests.Count, "requests");
    Assert.AreEqual(1, observer.PublishedResponses.Count, "responses");

}