c# - 使用 C# - .Net Core 进行单元测试 RabbitMQ 推送

Question

我已经创建了一个 .net 核心 API，它将消息推送到 RabbitMQ 队列中。我已使用 IOptions 从 .json 文件中读取配置数据并将其添加为依赖项。

下面是我的 Controller 的代码:

[Route("api/[controller]")]
public class RestController : Controller
{
    private RabbitMQConnectionDetail _connectionDetail;

    public RestController(IOptions<RabbitMQConnectionDetail> connectionDetail)
    {
        _connectionDetail = connectionDetail.Value;
    }

    [HttpPost]
    public IActionResult Push([FromBody] OrderItem orderItem)
    {
        try
        {
            using (var rabbitMQConnection = new RabbitMQConnection(_connectionDetail.HostName,
                _connectionDetail.UserName, _connectionDetail.Password))
            {
                using (var connection = rabbitMQConnection.CreateConnection())
                {
                    var model = connection.CreateModel();
                    var helper = new RabbitMQHelper(model, "Topic_Exchange");
                    helper.PushMessageIntoQueue(orderItem.Serialize(), "Order_Queue");
                }
            }
        }
        catch (Exception)
        {
            return StatusCode((int)HttpStatusCode.BadRequest);
        }
        return Ok();
    }
 }

连接详细信息类具有以下属性

public class RabbitMQConnectionDetail
{
    public string HostName { get; set; }

    public string UserName { get; set; }

    public string Password { get; set; }
}

现在我想对其进行单元测试，但由于我要针对黑盒对其进行测试，所以我无法想到如何对其进行单元测试并寻求帮助。

连接类

public class RabbitMQConnection : IDisposable
{   
    private static IConnection _connection;
    private readonly string _hostName;
    private readonly string _userName;
    private readonly string _password;

    public RabbitMQConnection(string hostName, string userName, string password)
    {
        _hostName = hostName;
        _userName = userName;
        _password = password;
    }

    public IConnection CreateConnection()
    {
        var _factory = new ConnectionFactory
        {
            HostName = _hostName,
            UserName = _userName,
            Password = _password
        };
        _connection = _factory.CreateConnection();
        var model = _connection.CreateModel();

        return _connection;
    }

    public void Close()
    {
        _connection.Close();
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (disposing)
        {
            _connection.Close();
        }
    }

    ~ RabbitMQConnection()
    {
        Dispose(false);
    }
}

辅助类

public class RabbitMQHelper
{
    private static IModel _model;
    private static string _exchangeName;
    const string RoutingKey = "dummy-key.";

    public RabbitMQHelper(IModel model, string exchangeName)
    {
        _model = model;
        _exchangeName = exchangeName;
    }


    public void SetupQueue(string queueName)
    {
        _model.ExchangeDeclare(_exchangeName, ExchangeType.Topic);
        _model.QueueDeclare(queueName, true, false, false, null);
        _model.QueueBind(queueName, _exchangeName, RoutingKey);
    }

    public void PushMessageIntoQueue(byte[] message, string queue)
    {
        SetupQueue(queue);
        _model.BasicPublish(_exchangeName, RoutingKey, null, message);
    }

    public byte[] ReadMessageFromQueue(string queueName)
    {
        SetupQueue(queueName);
        byte[] message;
        var data = _model.BasicGet(queueName, false);
        message = data.Body;
        _model.BasicAck(data.DeliveryTag, false);
        return message;
    }
}

Answer 1

将您的 Controller 与实现问题紧密耦合使得很难在没有副作用的情况下测试您的 Controller 。从您提供的示例中，您已经表明您正在封装第 3 部分 API 实现并且仅公开抽象。好的。但是，您还没有创建允许您在测试时模拟它们的抽象。我建议重构 RabbitMQConnection 以实现这一点。

首先要有自己的支持抽象。

public interface IRabbitMQConnectionFactory {
    IConnection CreateConnection();
}

并重构RabbitMQConnection如下

public class RabbitMQConnection : IRabbitMQConnectionFactory {
    private readonly RabbitMQConnectionDetail connectionDetails;

    public RabbitMQConnection(IOptions<RabbitMQConnectionDetail> connectionDetails) {
        this.connectionDetails = connectionDetails.Value;
    }

    public IConnection CreateConnection() {
        var factory = new ConnectionFactory {
            HostName = connectionDetails.HostName,
            UserName = connectionDetails.UserName,
            Password = connectionDetails.Password
        };
        var connection = factory.CreateConnection();
        return connection;
    }
}

花点时间仔细看看这次重构做了什么。 IOptions 已从 Controller 移至工厂，并且 RabbitMQConnection 也已简化以实现其预期目的。创建连接。

Controller 现在也需要重构

[Route("api/[controller]")]
public class RestController : Controller {
    private readonly IRabbitMQConnectionFactory factory;

    public RestController(IRabbitMQConnectionFactory factory) {
        this.factory = factory;
    }

    [HttpPost]
    public IActionResult Push([FromBody] OrderItem orderItem) {
        try {                
            using (var connection = factory.CreateConnection()) {
                var model = connection.CreateModel();
                var helper = new RabbitMQHelper(model, "Topic_Exchange");
                helper.PushMessageIntoQueue(orderItem.Serialize(), "Order_Queue");
                return Ok();
            }
        } catch (Exception) {
            //TODO: Log error message
            return StatusCode((int)HttpStatusCode.BadRequest);
        }
    }
}

再次注意 Controller 的简化。这现在允许工厂在测试时被模拟和注入(inject)，并且通过扩展允许模拟被 RabbitMQHelper 使用。您可以将您选择的模拟框架用于依赖项或纯 DI。