如何使用[ UnitTesting ]通过UnitTesting创建和启动TCP服务器？

Question

我正在做的是以计算程序的形式使用TCP客户端到服务器。"client“输入一个数学命令和两个数字，服务器为他执行计算并返回一个结果(exp )。加5 5；结果是10)。要做到这一点，服务器需要启动并运行，然后客户端应该尝试连接。服务器和客户端是两个不同的控制台应用程序。

现在，为了测试程序，我将与客户端相关的代码移动到一个测试项目中，并从它的正常项目中运行服务器。这是可行的，测试通过了：

 [TestClass]
 public class UnitTest1
 {
    static TcpClient connectionSocket = new TcpClient("localhost", 5678);
    static Stream ns = connectionSocket.GetStream();
    static StreamReader sr = new StreamReader(ns);
    static StreamWriter sw = new StreamWriter(ns);
    [TestMethod]
    public void TestMethodAdd()
    {
        int response = GetResponce("Add 5 5");
        Assert.AreEqual(response, 10);
    }

    [TestMethod]
    public void TestMethodSubstract()
    {
        int response = GetResponce("Substract 5 5");
        Assert.AreEqual(response, 0);
    }

    [TestMethod]
    public void TestMethodMultiply()
    {
        int response = GetResponce("Multiply 5 5");
        Assert.AreEqual(response, 25);
    }

    [TestMethod]
    public void TestMethodDivide()
    {
        int response = GetResponce("Divide 5 5");
        Assert.AreEqual(response, 1);
    }

    [TestMethod]
    public void TestMethodPercent()
    {
        int response = GetResponce("Percent 100 5");
        Assert.AreEqual(response, 5);
        KillConnection();
    }

    private static void KillConnection()
    {
        connectionSocket.Close();
        ns.Close();
    }

    private static int GetResponce(string request)
    {
        sw.AutoFlush = true;
        sw.WriteLine(request);
        string message = sr.ReadLine();
        return Convert.ToInt32(message);
    }
}

我应该执行的下一步是使单元测试自给自足，将其编码为通过ClassInitialize自己创建、启动和停止服务器。

我该怎么做？

这不工作，我的尝试是移动测试类中的服务器代码，然后运行使用ClassInitialize启动它的方法。

        class TcpChatServerA
{
    public void StartServer()
    {
        TcpListener listener = new TcpListener(5678);
        //Console.WriteLine("Server is started.");
        listener.Start();
        TcpClient connectionSocket = listener.AcceptTcpClient();
        ChatService service = new ChatService(connectionSocket);
        service.ServiceHandler();
        listener.Stop();
    }
}

class ChatService
{
    private TcpClient connectionSocket;
    public ChatService(TcpClient connectonSocketEntry)
    {
        connectionSocket = connectonSocketEntry;
    }
    public void ServiceHandler()
    {

        //Console.WriteLine("Server is activated");
        Stream ns = connectionSocket.GetStream();
        StreamReader sr = new StreamReader(ns);
        StreamWriter sw = new StreamWriter(ns);
        sw.AutoFlush = true;
        string message = sr.ReadLine();
        char[] deliminerChars = { ' ', ',', '.', '/', ':', ';' };
        string[] equationMembers = new string[5];
        int result = 0;
        while (message != null)
        {
            equationMembers = message.Split(deliminerChars);
            switch (equationMembers[0])
            {
                case "Add":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) + Convert.ToInt32(equationMembers[2]));
                    break;
                case "Substract":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) - Convert.ToInt32(equationMembers[2]));
                    break;
                case "Multiply":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) * Convert.ToInt32(equationMembers[2]));
                    break;
                case "Divide":
                    if (equationMembers[1] == "0")
                    {
                        message = "You attempt to divide by zero please try again";
                    }
                    else if (equationMembers[2] == "0")
                    {
                        message = "You attempt to divide by zero please try again";
                    }
                    else
                    {
                        message = Convert.ToString(Convert.ToDecimal(equationMembers[1]) / Convert.ToDecimal(equationMembers[2]));
                        ;
                    }
                    break;
                case "Percent":
                    message = Convert.ToString(((Convert.ToDecimal(equationMembers[2])) / 100) * Convert.ToDecimal(equationMembers[1]));
                    break;
                default:
                    Console.WriteLine("You did not enter a valid equation command. Valid commands are " +
                                      "'Add', 'Substract', 'Multiply', 'Divide', Percent (y% (from) x)");
                    break;
            }
            //Console.WriteLine("Calculating...");
            sw.WriteLine(message);
            message = sr.ReadLine();
        }
        ns.Close();
        connectionSocket.Close();
    }
}

并启动服务器：

[TestClass]
public class UnitTest1
{
    [ClassInitialize]
    static void Main(string[] args)
    {
        TcpChatServerA server = new TcpChatServerA();
        server.StartServer();
    }

    //the rest is the test class as seen in the first code block

    //static TcpClient connectionSocket = new TcpClient("localhost", 5678);
    //static Stream ns = connectionSocket.GetStream();
    //static StreamReader sr = new StreamReader(ns);
    //static StreamWriter sw = new StreamWriter(ns);

    //[TestMethod]
    //public void TestMethodAdd()
    //{
        //int response = GetResponce("Add 5 5");
        //Assert.AreEqual(response, 10);
    //}
    //...

因此，整个守则将是：

using System;
using System.IO;
using System.Net.Sockets;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace MathTCPServerTest
{
class TcpChatServerA
{
    public void StartServer()
    {
        TcpListener listener = new TcpListener(5678);
        //Console.WriteLine("Server is started.");
        listener.Start();
        TcpClient connectionSocket = listener.AcceptTcpClient();
        ChatService service = new ChatService(connectionSocket);
        service.ServiceHandler();
        listener.Stop();
    }
}

class ChatService
{
    private TcpClient connectionSocket;
    public ChatService(TcpClient connectonSocketEntry)
    {
        connectionSocket = connectonSocketEntry;
    }
    public void ServiceHandler()
    {

        //Console.WriteLine("Server is activated");
        Stream ns = connectionSocket.GetStream();
        StreamReader sr = new StreamReader(ns);
        StreamWriter sw = new StreamWriter(ns);
        sw.AutoFlush = true;
        string message = sr.ReadLine();
        char[] deliminerChars = { ' ', ',', '.', '/', ':', ';' };
        string[] equationMembers = new string[5];
        int result = 0;
        while (message != null)
        {
            equationMembers = message.Split(deliminerChars);
            switch (equationMembers[0])
            {
                case "Add":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) + Convert.ToInt32(equationMembers[2]));
                    break;
                case "Substract":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) - Convert.ToInt32(equationMembers[2]));
                    break;
                case "Multiply":
                    message = Convert.ToString(Convert.ToInt32(equationMembers[1]) * Convert.ToInt32(equationMembers[2]));
                    break;
                case "Divide":
                    if (equationMembers[1] == "0")
                    {
                        message = "You attempt to divide by zero please try again";
                    }
                    else if (equationMembers[2] == "0")
                    {
                        message = "You attempt to divide by zero please try again";
                    }
                    else
                    {
                        message = Convert.ToString(Convert.ToDecimal(equationMembers[1]) / Convert.ToDecimal(equationMembers[2]));
                        ;
                    }
                    break;
                case "Percent":
                    message = Convert.ToString(((Convert.ToDecimal(equationMembers[2])) / 100) * Convert.ToDecimal(equationMembers[1]));
                    break;
                default:
                    Console.WriteLine("You did not enter a valid equation command. Valid commands are " +
                                      "'Add', 'Substract', 'Multiply', 'Divide', Percent (y% (from) x)");
                    break;
            }
            //Console.WriteLine("Calculating...");
            sw.WriteLine(message);
            message = sr.ReadLine();
        }
        ns.Close();
        connectionSocket.Close();
    }
}

[TestClass]
public class UnitTest1
{
    [ClassInitialize]
    static void Main(string[] args)
    {
        TcpChatServerA server = new TcpChatServerA();
        server.StartServer();
    }

    static TcpClient connectionSocket = new TcpClient("localhost", 5678);
    static Stream ns = connectionSocket.GetStream();
    static StreamReader sr = new StreamReader(ns);
    static StreamWriter sw = new StreamWriter(ns);

    [TestMethod]
    public void TestMethodAdd()
    {
        int response = GetResponce("Add 5 5");
        Assert.AreEqual(response, 10);
    }

    [TestMethod]
    public void TestMethodSubstract()
    {
        int response = GetResponce("Substract 5 5");
        Assert.AreEqual(response, 0);
    }

    [TestMethod]
    public void TestMethodMultiply()
    {
        int response = GetResponce("Multiply 5 5");
        Assert.AreEqual(response, 25);
    }

    [TestMethod]
    public void TestMethodDivide()
    {
        int response = GetResponce("Divide 5 5");
        Assert.AreEqual(response, 1);
    }

    [TestMethod]
    public void TestMethodPercent()
    {
        int response = GetResponce("Percent 100 5");
        Assert.AreEqual(response, 5);
        KillConnection();
    }

    private static void KillConnection()
    {
        connectionSocket.Close();
        ns.Close();
    }

    private static int GetResponce(string request)
    {
        sw.AutoFlush = true;
        sw.WriteLine(request);
        string message = sr.ReadLine();
        return Convert.ToInt32(message);
    }
}
}

这给我带来了以下错误：

测试名称: TestMethodPercent

测试FullName: MathTCPServerTest.UnitTest1.TestMethodPerent

测试源:我的目录\MathTCPServerTest\UnitTest1.cs:第132行

测试结果:失败

测试持续时间: 0:00:00

结果StackTrace：

在System.Net.Sockets.TcpClient..ctor(字符串主机名，Int32端口)

at MathTCPServerTest.UnitTest1..cctor() in _My Directories_\MathTCPServerTest\UnitTest1.cs:line 97

-内部异常堆栈跟踪结束

 at MathTCPServerTest.UnitTest1..ctor() Result Message: Unable to create instance of class MathTCPServerTest.UnitTest1. Error: System.TypeInitializationException: The type initializer for 'MathTCPServerTest.UnitTest1' threw an exception. --->   System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 127.0.0.1:5678.

我没有正确理解ClassInitialize，是吗？

PS：对于代码改进以及如何更好地在堆栈溢出中提出问题和问题，我都愿意听取建议。

Answer 1

如何为每个单元测试创建、启动和处理TCP服务器

我应该执行的下一步是使单元测试自给自足，将其编码为通过ClassInitialize自己创建、启动和停止服务器。 我该怎么做？

由于您希望开始和停止每个单元测试，并且在一个[TestClass]中包含其中的几个，所以[ClassInitialize]在这里没有用处。一种方法是将您的测试环境封装在实现IDisposable的类中，然后在单元测试中的using块中使用它。下面的代码会这样做，并回答了如何为每个单元测试创建、启动和释放TCP服务器的问题。

using System;
using System.Net.Sockets;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Net;

namespace TCPServerTest
{
    class TestEnvironment : IDisposable
    {
        TcpListener TcpServer;

        readonly public int TcpServerAddress;

        public TestEnvironment(int TcpServerAddress = 5678)
        {
            this.TcpServerAddress = TcpServerAddress;

            TcpServer = new TcpListener(IPAddress.Loopback, TcpServerAddress);

            TcpServer.Start();
        }

        public void Dispose()
        {
            TcpServer.Stop();
        }
    }

    [TestClass]
    public class TestContainer
    {
        [TestMethod]
        public void TestUsingTcpServer()
        {
            using (var TestEnvironment = new TestEnvironment())
            {
                var TcpClient = new TcpClient();

                TcpClient.Connect(IPAddress.Loopback, TestEnvironment.TcpServerAddress);

                Assert.IsTrue(TcpClient.Connected, "TcpClient.Connected");
            }
        }
    }
}

论ClassInitialize

我没有正确理解ClassInitialize，是吗？

考虑到你发布的代码，这似乎是可能的。这就是框架对带有[ClassInitialize]属性的方法的说明：

该方法必须是静态的、公共的，不返回值，并且应该接受TestContext类型的单个参数。

但是，即使您使用了[ClassInitialize]所需的签名，您仍然会得到相同的异常，因为您的静态字段初始化器(异常产生的地方)是在前面执行的。

Answer 2

我认为您已经很好地理解了ClassInitialize，但是问题是您得到了一个Type初始化异常，这个异常通常是在类的静态字段无法初始化时抛出的。我不认为您可以使TcpClient和static -它们应该在方法的某个地方被初始化。我建议删除UnitTest1类中的所有静态字段，然后将它们移到GetResponse方法中，如下所示：

private static int GetResponce(string request)
{
    TcpClient connectionSocket = new TcpClient("localhost", 5678);
    Stream ns = connectionSocket.GetStream();
    StreamReader sr = new StreamReader(ns);
    StreamWriter sw = new StreamWriter(ns);

    sw.AutoFlush = true;
    sw.WriteLine(request);
    string message = sr.ReadLine();
    return Convert.ToInt32(message);
}

(这个应该很好地工作:)