可测试的HttpModule和HttpHandler

用新的System.Web.Abstraction名称空间我们能轻易写出可测试的HttpModule和HttpHandler。在这篇post中，
我将向你展示如何写可测试的HttpModule和HttpHandler。

之前发布的System.Web.Abstraction的单元测试这些web的基础构件HttpContext的问题。它是密封的，无法用Rhino或Moq来mock.唯一的选择是为这些不能MOCK的对象创建包装对象，但它又有像HttpRequest, HttpResponse, HttpSessionState, HttpServerUtility等。同时这的确是System.Web.Abstraction所提供的，所有包在外面不可mock的HttpContext对象。但是HttpModule 和HttpHandler紧密依赖于原生HttpContext之上，我希望ASP.NET 4.0将改变，直到我们需要创建一个特别层来实现对它的单元测试。

HttpModule

1. public abstract class BaseHttpModule : IHttpModule   
2. {   
3.     public void Init(HttpApplication context)   
4.     {   
5.         context.BeginRequest += (sender, e) => OnBeginRequest(new HttpContextWrapper(((HttpApplication) sender).Context));   
6.         context.Error += (sender, e) => OnError(new HttpContextWrapper(((HttpApplication) sender).Context));   
7.         context.EndRequest += (sender, e) => OnEndRequest(new HttpContextWrapper(((HttpApplication) sender).Context));   
8.     }   
9.   
10.     public void Dispose()   
11.     {   
12.     }   
13.   
14.     public virtual void OnBeginRequest(HttpContextBase context)   
15.     {   
16.     }   
17.   
18.     public virtual void OnError(HttpContextBase context)   
19.     {   
20.     }   
21.   
22.     public virtual void OnEndRequest(HttpContextBase context)   
23.     {   
24.     }   
25. }  

public abstract class BaseHttpModule : IHttpModule { public void Init(HttpApplication context) { context.BeginRequest += (sender, e) => OnBeginRequest(new HttpContextWrapper(((HttpApplication) sender).Context)); context.Error += (sender, e) => OnError(new HttpContextWrapper(((HttpApplication) sender).Context)); context.EndRequest += (sender, e) => OnEndRequest(new HttpContextWrapper(((HttpApplication) sender).Context)); } public void Dispose() { } public virtual void OnBeginRequest(HttpContextBase context) { } public virtual void OnError(HttpContextBase context) { } public virtual void OnEndRequest(HttpContextBase context) { } }}

如果你的应用程序需要，它能挂起其它事件。现在让我们创建一个基本的从url访问的HttpModule:

1. public class RemoveWwwModule : BaseHttpModule   
2. {   
3.     public override void OnBeginRequest(HttpContextBase context)   
4.     {   
5.         const string Prefix = "http://www.";   
6.   
7.         string url = context.Request.Url.ToString();   
8.   
9.         bool startsWith3W = url.StartsWith(Prefix, StringComparison.OrdinalIgnoreCase);   
10.   
11.         if (startsWith3W)   
12.         {   
13.             string newUrl = "http://" + url.Substring(Prefix.Length);   
14.   
15.             HttpResponseBase response = context.Response;   
16.   
17.             response.StatusCode = (int) HttpStatusCode.MovedPermanently;   
18.             response.Status = "301 Moved Permanently";   
19.             response.RedirectLocation = newUrl;   
20.             response.SuppressContent = true;   
21.             response.End();   
22.         }   
23.     }   
24. }  

public class RemoveWwwModule : BaseHttpModule { public override void OnBeginRequest(HttpContextBase context) { const string Prefix = "http://www."; string url = context.Request.Url.ToString(); bool startsWith3W = url.StartsWith(Prefix, StringComparison.OrdinalIgnoreCase); if (startsWith3W) { string newUrl = "http://" + url.Substring(Prefix.Length); HttpResponseBase response = context.Response; response.StatusCode = (int) HttpStatusCode.MovedPermanently; response.Status = "301 Moved Permanently"; response.RedirectLocation = newUrl; response.SuppressContent = true; response.End(); } } }

Unit Test:

1. public class RemoveWwwModuleFixture   
2. {   
3.     private readonly Mock<HttpContextBase> _httpContext;   
4.     private readonly Mock<HttpRequestBase> _httpRequest;   
5.     private readonly Mock<HttpResponseBase> _httpResponse;   
6.   
7.     public RemoveWwwModuleFixture()   
8.     {   
9.         _httpContext = new Mock<HttpContextBase>();   
10.         _httpRequest = new Mock<HttpRequestBase>();   
11.         _httpResponse = new Mock<HttpResponseBase>();   
12.   
13.         _httpContext.SetupGet(context => context.Request).Returns(_httpRequest.Object);   
14.         _httpContext.SetupGet(context => context.Response).Returns(_httpResponse.Object);   
15.     }   
16.   
17.     [Fact]   
18.     public void OnBeginRequest_Should_Redirect_When_Requesting_Url_Which_Starts_With_WWW()   
19.     {   
20.         _httpRequest.SetupGet(request => request.Url).Returns(new Uri("http://www./"));   
21.   
22.         _httpResponse.SetupSet(response => response.StatusCode = (int) HttpStatusCode.MovedPermanently);   
23.         _httpResponse.SetupSet(response => response.Status = "301 Moved Permanently");   
24.         _httpResponse.SetupSet(response => response.RedirectLocation = "http:///");   
25.         _httpResponse.SetupSet(response => response.SuppressContent = true);   
26.         _httpResponse.Setup(response => response.End());   
27.   
28.         var module = new RemoveWwwModule();   
29.   
30.         module.OnBeginRequest(_httpContext.Object);   
31.   
32.         _httpResponse.VerifyAll();   
33.     }   
34. }  

public class RemoveWwwModuleFixture { private readonly Mock<HttpContextBase> _httpContext; private readonly Mock<HttpRequestBase> _httpRequest; private readonly Mock<HttpResponseBase> _httpResponse; public RemoveWwwModuleFixture() { _httpContext = new Mock<HttpContextBase>(); _httpRequest = new Mock<HttpRequestBase>(); _httpResponse = new Mock<HttpResponseBase>(); _httpContext.SetupGet(context => context.Request).Returns(_httpRequest.Object); _httpContext.SetupGet(context => context.Response).Returns(_httpResponse.Object); } [Fact] public void OnBeginRequest_Should_Redirect_When_Requesting_Url_Which_Starts_With_WWW() { _httpRequest.SetupGet(request => request.Url).Returns(new Uri("http://www./")); _httpResponse.SetupSet(response => response.StatusCode = (int) HttpStatusCode.MovedPermanently); _httpResponse.SetupSet(response => response.Status = "301 Moved Permanently"); _httpResponse.SetupSet(response => response.RedirectLocation = "http:///"); _httpResponse.SetupSet(response => response.SuppressContent = true); _httpResponse.Setup(response => response.End()); var module = new RemoveWwwModule(); module.OnBeginRequest(_httpContext.Object); _httpResponse.VerifyAll(); } }}

HttpHandler



    
public abstract class BaseHttpHandler : IHttpHandler   
    
{   
    
    public virtual bool IsReusable   
    
    {   
    
        get  
    
        {   
    
            return false;   
    
        }   
    
    }   
    
  
    
    public void ProcessRequest(HttpContext context)   
    
    {   
    
        ProcessRequest(new HttpContextWrapper(context));   
    
    }   
    
  
    
    public abstract void ProcessRequest(HttpContextBase context);   
    
}   



现在让我们创建结合些Javascript文件的HttpHandler,我将在Post中跳过如果是不相关的部分。



    
public class JavaScriptHandler : BaseHttpHandler   
    
{   
    
    public override void ProcessRequest(HttpContextBase context)   
    
    {   
    
        string content = GetContent();   
    
        HttpResponseBase response = context.Response;   
    
  
    
        response.ContentType = "application/x-javascript";   
    
        response.Write(content);   
    
    }   
    
  
    
    private string GetContent()   
    
    {   
    
        return "YOUR JAVA SCRIPT FILES CONTENT";   
    
    }   
    
}   


public class JavaScriptHandler : BaseHttpHandler { public override void ProcessRequest(HttpContextBase context) { string content = GetContent(); HttpResponseBase response = context.Response; response.ContentType = "application/x-javascript"; response.Write(content); } private string GetContent() { return "YOUR JAVA SCRIPT FILES CONTENT"; } }

Unit Test:



    
public class JavaScriptHandlerFixture : IDisposable   
    
{   
    
    private readonly Mock<HttpContextBase> _httpContext;   
    
    private readonly Mock<HttpResponseBase> _httpResponse;   
    
  
    
    private readonly JavaScriptHandler _handler;   
    
  
    
    public JavaScriptHandlerFixture()   
    
    {   
    
        _httpContext = new Mock<HttpContextBase>();   
    
        _httpResponse = new Mock<HttpResponseBase>();   
    
  
    
        _httpContext.SetupGet(context => context.Response).Returns(_httpResponse.Object);   
    
  
    
        _handler = new JavaScriptHandler();   
    
    }   
    
  
    
    public void Dispose()   
    
    {   
    
        _httpResponse.VerifyAll();   
    
    }   
    
  
    
    [Fact]   
    
    public void ProcessRequest_Should_Set_Correct_ContentType()   
    
    {   
    
        _httpResponse.SetupSet(response => response.ContentType = "application/x-javascript");   
    
  
    
        _handler.ProcessRequest(_httpContext.Object);   
    
    }   
    
  
    
    [Fact]   
    
    public void ProcessRequest_Should_Write_Content()   
    
    {   
    
        _httpResponse.Setup(response => response.Write(It.IsAny<string>()));   
    
  
    
        _handler.ProcessRequest(_httpContext.Object);   
    
    }   
    
}   


public class JavaScriptHandlerFixture : IDisposable { private readonly Mock<HttpContextBase> _httpContext; private readonly Mock<HttpResponseBase> _httpResponse; private readonly JavaScriptHandler _handler; public JavaScriptHandlerFixture() { _httpContext = new Mock<HttpContextBase>(); _httpResponse = new Mock<HttpResponseBase>(); _httpContext.SetupGet(context => context.Response).Returns(_httpResponse.Object); _handler = new JavaScriptHandler(); } public void Dispose() { _httpResponse.VerifyAll(); } [Fact] public void ProcessRequest_Should_Set_Correct_ContentType() { _httpResponse.SetupSet(response => response.ContentType = "application/x-javascript"); _handler.ProcessRequest(_httpContext.Object); } [Fact] public void ProcessRequest_Should_Write_Content() { _httpResponse.Setup(response => response.Write(It.IsAny<string>())); _handler.ProcessRequest(_httpContext.Object); } }}

如果你要看更多的可单元测试HttpModule and HttpHandler，到KiGG源代中查看吧。
翻译:Petter Liu   http://wintersun.cnblogs.com   原文：Source