如何用HttpApplicationState测试HttpApplication对象

Question

我正在尝试测试一个加载在Application_Start上的ASP.NET HttpApplication的‘插件’。

代码如下所示：

private HttpApplication application;

public void Application_Start(object sender, EventArgs e)
{
    this.application = sender as HttpApplication;

    StartReportService();
}

private void StartReportService()
{

    HandledReports = new SortedList<string, string>();
    HandledReports.Add("myindex","myvalue");

}

public System.Collections.Generic.SortedList<String, String> HandledReports
{
    get 
    {
        application.Application.Lock();
        var handledReports = (SortedList<String, String>)application.Application["handledReports"];
        application.Application.UnLock();
        return handledReports;
    }
    set 
    { 
        application.Application.Lock();
        application.Application["handledReports"] = value; 
        application.Application.UnLock();
    }
}

问题是我找不到测试HttpApplicationState的好方法，主要是因为HttpApplication.Application属性不可重写，而且System.Web.Abstractions中似乎没有允许这样做的HttpApplicationBase类。

我尝试过以下几种方法，每次都会遇到路障。

[TestMethod()]
public void StartReportService_ApplicationStateShouldContainMyIndex()
{
    //No HttpApplicationBase in System.Web.Abstractions, must use Real Object
    var application = new Mock<HttpApplication>();

    //Real object does not have a property of type HttpApplicationStateBase so must use real one?
    //var applicationStateBase = new Mock<HttpApplicationStateBase>();

    //real one not creable so HACK get private constructor
    var ctor = typeof(HttpApplicationState).GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, new Type[] { }, new ParameterModifier[] { });
    var applicationState = (HttpApplicationState)ctor.Invoke(new Object[] { });

    //fails here, HttpApplication.Application not overridable
    application.SetupProperty(x => x.Application, applicationState);


    var plugin = HttpApplicationPlugin.HttpApplicationPluginInstance;
    plugin.Application_Start(application.Object,null);

    ...evaluate result...
}

有人能为我介绍一些好的方法吗？这是第一次对更多的测试，这将依赖于能够有一个正常工作的HttpApplicationState被模仿。

Answer 1

好吧，经过一些仔细的思考和一些反思:)，我想出了这个解决我自己的问题的方案来让我继续前进：

 [TestMethod()]
 public void StartReportService_ApplicationStateShouldContainMyIndex()
 {
    HttpApplicationPlugin plugin=null;
    HttpApplication app = null;
    HttpApplicationState applicationState = null;
    String tempDir = "";
    try
    {
        #region "Create HttpApplication and ApplicationState"

        //No HttpApplicationBase in System.Web.Abstractions, must use Real Object
        app = new HttpApplication();

        //real one not creatable so HACK get private constructor
        var ctor = typeof(HttpApplicationState).GetConstructor(
                      BindingFlags.Instance | BindingFlags.NonPublic, 
                      null, new Type[] { }, new ParameterModifier[] { });
        applicationState = (HttpApplicationState)ctor.Invoke(new Object[] { });

        //HACK in the state prop for testing
        var stateProp = typeof(HttpApplication).GetField(
                           "_state", BindingFlags.Instance | BindingFlags.NonPublic);
        stateProp.SetValue(app, applicationState);

        #endregion


       plugin = HttpApplicationPlugin.HttpApplicationPluginInstance;
       plugin.Application_Start(application.Object,null);          

本质上，您可以使用反射为您提供一个带有HttpApplicationState对象的HttpApplication对象，该对象足以测试依赖于它的代码块。