c#-单元测试、模拟和ninject工厂扩展

我有一个控制台应用程序，用户在其中输入一个数字，我根据该数字生成一个功能。为此，我使用了

Ninject.Extensions.Factory

，以下是绑定：

    Bind<IFeature>().To<FirstFeature>().Named("1");
    Bind<IFeature>().To<SecondFeature>().Named("2");
    Bind<IFeature>().To<ThirdFeature>().Named("3");
    Bind<IFeatureFactory>().ToFactory(() => new UseFirstArgumentAsNameInstanceProvider());

被测方法：

public FeatureService(IFeatureFactory featureFactory, IUILayer uiHandler, int howManyFeatures)
    {
        this.featureFactory = featureFactory;
        this.uiHandler = uiHandler;
        this.howManyFeatures = howManyFeatures;
    }

public async Task startService()
    {
        bool isBadInput = false;
        string userSelection = null;
        uiHandler.displayMenu(howManyFeatures);
        userSelection = uiHandler.getSelection();
        while (!userSelection.Equals((howManyFeatures+1).ToString()))
        {
            IFeature feature = null;
            try
            {
                feature = featureFactory.createFeature(userSelection);
                isBadInput = false;
            }
            catch (ActivationException ex)
            {
                uiHandler.displayErrorMessage();
                isBadInput = true;
            }
            if (!isBadInput)
            {
                await feature.execFeature();
            }
            uiHandler.displayMenu(howManyFeatures);
            userSelection = uiHandler.getSelection();
        }
    }

    [TestMethod]
    public void WhenUserEnterValidSelectionExecFeatureCalled()
    {
        //Arrange
        Mock<IFeature> featureMock = new Mock<IFeature>();
        Mock<IConsoleService> consoleServiceMock = new Mock<IConsoleService>();
        // mock user input 7
        consoleServiceMock.Setup(c => c.ReadLine()).Returns("7");
        IUILayer uiLayer = new ConsoleUILayer(consoleServiceMock.Object);
        Mock<IFeatureFactory> featureFactory = new Mock<IFeatureFactory>();
        featureMock.Setup(t => t.execFeature());
        featureFactory.Setup(t => t.createFeature(It.IsAny<string>())).Returns(featureMock.Object);
        // init FeatureService with 3 features
        IFeatureService featureService = new FeatureService(featureFactory.Object, uiLayer, 3);

        //Act
        featureService.startService();

        //Assert
        featureMock.Verify(t => t.execFeature());
    }

如您所见，当我

尝试
创建功能时，我
捕获
激活异常
，这意味着用户输入了无效的选择（ninject无法获得具体的类），并且未调用
execFeature

我试图编写一个单元测试来测试当用户输入一个有效的选择时，方法
execFeature
被称为

下面是测试：

public FeatureService(IFeatureFactory featureFactory, IUILayer uiHandler, int howManyFeatures)
    {
        this.featureFactory = featureFactory;
        this.uiHandler = uiHandler;
        this.howManyFeatures = howManyFeatures;
    }

public async Task startService()
    {
        bool isBadInput = false;
        string userSelection = null;
        uiHandler.displayMenu(howManyFeatures);
        userSelection = uiHandler.getSelection();
        while (!userSelection.Equals((howManyFeatures+1).ToString()))
        {
            IFeature feature = null;
            try
            {
                feature = featureFactory.createFeature(userSelection);
                isBadInput = false;
            }
            catch (ActivationException ex)
            {
                uiHandler.displayErrorMessage();
                isBadInput = true;
            }
            if (!isBadInput)
            {
                await feature.execFeature();
            }
            uiHandler.displayMenu(howManyFeatures);
            userSelection = uiHandler.getSelection();
        }
    }

    [TestMethod]
    public void WhenUserEnterValidSelectionExecFeatureCalled()
    {
        //Arrange
        Mock<IFeature> featureMock = new Mock<IFeature>();
        Mock<IConsoleService> consoleServiceMock = new Mock<IConsoleService>();
        // mock user input 7
        consoleServiceMock.Setup(c => c.ReadLine()).Returns("7");
        IUILayer uiLayer = new ConsoleUILayer(consoleServiceMock.Object);
        Mock<IFeatureFactory> featureFactory = new Mock<IFeatureFactory>();
        featureMock.Setup(t => t.execFeature());
        featureFactory.Setup(t => t.createFeature(It.IsAny<string>())).Returns(featureMock.Object);
        // init FeatureService with 3 features
        IFeatureService featureService = new FeatureService(featureFactory.Object, uiLayer, 3);

        //Act
        featureService.startService();

        //Assert
        featureMock.Verify(t => t.execFeature());
    }

[TestMethod]
当UserIntervalidSelectionExecFeatureCalled（）时公共无效
{
//安排
Mock featureMock=新建Mock（）；
模拟控制台服务模拟=新建模拟（）；
//模拟用户输入7
consoleServiceMock.Setup（c=>c.ReadLine（））。返回（“7”）；
IUILayer uiLayer=新的ConsoleUILayer（consoleServiceMock.Object）；
Mock featureFactory=new Mock（）；
featureMock.Setup（t=>t.execFeature（））；
Setup（t=>t.createFeature（It.IsAny（））.Returns（featureMock.Object）；
//init FeatureService具有3个功能
IFeatureService featureService=新的featureService（featureFactory.Object，uiLayer，3）；
//表演
featureService.startService（）；
//断言
验证（t=>t.execFeature（））；
}

如您所见-我正在创建一个
控制台，用户输入为“7”，
当我创建
FeatureService
时，我将3放在
howManyFeatures
-测试应该失败的地方（没有具体的实现）

现在，当我正常运行我的程序时——如果我输入“7”，程序将按预期运行并输出错误消息

当我运行测试时，除了
HowManyFeatures+1
之外，控制台的每个输入都通过了测试（
HowManyFeatures+1
失败，因为它没有进入
while
），它不应该是这样的-它应该失败，因为没有具体的
IFeature
实现（只有1、2和3有具体的实现）

我该如何解决这个问题？我应该将
Ninject绑定
引入
Tests
项目吗？我甚至应该测试这个方法吗？还是说它完全没有用

您不需要将ninject绑定带到您的测试中，您的FeatureService不需要知道IFeatureFactory基于ninject绑定，它也不关心它。

您需要做的是正确设置iFeatureFactory模拟，现在，无论输入是什么，模拟都会返回相同的IFeature，因为这是您告诉它要使用的行为：

 featureFactory.Setup(t => t.createFeature(It.IsAny<string>())).Returns(featureMock.Object);

featureFactory.Setup（t=>t.createFeature（It.IsAny（））.Returns（featureMock.Object）；

如果您希望它在获取大于3的数字时抛出ActivationException，只需设置此所需行为即可：

featureFactory.Setup(t => t.createFeature(It.Is<string>(input => (int)input>3 ))).Throws(new ActivationException()); 

featureFactory.Setup（t=>t.createFeature（It.Is（input=>（int）input>3））.Throws（new ActivationException（））；

顺便说一句，您可能应该直接模拟iUI层并将其注入FeatureService，而不是模拟consoleService并在真正的UiLayer实现中使用它，这将使您的测试更加容易