blocks|key|240312|text|在您的代码中，您不能拦截对HttpWebRequest的调用，因为您在相同的方法中创建了对象。如果您让另一个对象创建HttpWebRequest，则可以传入一个模拟对象并使用该对象进行测试。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|240313|因此，不是这样：|240314|HttpWebRequest+request+=+(HttpWebRequest)WebRequest.Create(_url);|code-block|syntax|javascript|240315|使用以下命令：|240316|IHttpWebRequest+request+=+this.WebRequestFactory.Create(_url);|240317|在您的单元测试中，您可以传入一个创建模拟对象的WebRequestFactory。|240318|此外，您可以在单独的函数中拆分流读取代码：|240319|using+(HttpWebResponse+response+=+(HttpWebResponse)request.GetResponse())
{
++++byte[]+data+=+ReadStream(response.GetResponseStream());
++++return+ExtractResponse(Encoding.UTF8.GetString(data));
}|240320|这使得单独测试ReadStream()成为可能。|240321|要执行更多的集成测试，您可以设置自己的HTTP服务器来返回测试数据，并将该服务器的URL传递给您的方法。|240322|entityMap^0|D|E|1M|E|0|0|0|0|0|N|H|0|0|0|7|C|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|17|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|18|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|19|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1A|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1B|8|@$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|S|3|T|5|6|7|1E|8|@]|D|@]|E|$]]|$1|U|3|V|5|J|7|1F|8|@]|D|@]|E|$K|L]]|$1|W|3|X|5|6|7|1G|8|@$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|Y|3|Z|5|6|7|1J|8|@]|D|@]|E|$]]|$1|10|3|-4|5|6|7|1K|8|@]|D|@]|E|$]]]|11|$]]

In your code you can not intercept the calls to <code>HttpWebRequest</code> because you create the object in the same method. If you let another object create the <code>HttpWebRequest</code>, you can pass in a mock object and use that to test.

So instead of this:

<pre><code>HttpWebRequest request = (HttpWebRequest)WebRequest.Create(_url);
</code></pre>

Use this:

<pre><code>IHttpWebRequest request = this.WebRequestFactory.Create(_url);
</code></pre>

In your unit test, you can pass in a <code>WebRequestFactory</code> which creates a mock object.

Furthermore, you can split of your stream reading code in a separate function:

<pre><code>using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
 byte[] data = ReadStream(response.GetResponseStream());
 return ExtractResponse(Encoding.UTF8.GetString(data));
}
</code></pre>

This makes it possible to test <code>ReadStream()</code> separately.

To do more of an integration test, you can set up your own HTTP server which returns test data, and pass the URL of that server to your method.

blocks|key|237839|text|我可能会从重构代码开始，以使其更弱地耦合到实际的HTTP请求。现在，这段代码似乎可以做很多事情。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|237840|这可以通过引入抽象来实现：|237841|public+interface+IDataRetriever
{
++++public+byte[]+RetrieveData(byte[]+request);
}|code-block|syntax|javascript|237842|现在，您尝试进行单元测试的类可以使用控制反转设计模式从实际的HTTP请求中解耦：|237843|public+class+ClassToTest
{
++++private+readonly+IDataRetriever+_dataRetriever;
++++public+Foo(IDataRetriever+dataRetriever)
++++{
++++++++_dataRetriever+=+dataRetriever;
++++}

++++public+string+MethodToTest(string+regularExpression,+string+strategy)
++++{
++++++++string+body+=+CreateHttpBody(regularExpression,+strategy);
++++++++byte[]+result+=+_dataRetriever.RetrieveData(Encoding.UTF8.GetBytes(body));
++++++++return+ExtractResponse(Encoding.UTF8.GetString(result));
++++}
}|237844|ClassToTest不再负责处理实际的HTTP请求。它现在是解耦的。测试MethodToTest成为一项微不足道的任务。|offset|length|style|CODE|237845|很明显，最后一部分是我们所介绍的抽象的实现：|237846|public+class+MyDataRetriever+:+IDataRetriever
{
++++private+readonly+string+_url;
++++public+MyDataRetriever(string+url)
++++{
++++++++_url+=+url;
++++}

++++public+byte[]+RetrieveData(byte[]+request)
++++{
++++++++using+(var+client+=+new+WebClient())
++++++++{
++++++++++++client.Headers[HttpRequestHeader.ContentType]+=+"text/plain;+charset=utf-8";
++++++++++++return+client.UploadData(_url,+request);
++++++++}
++++}
}|237847|然后，您可以配置您喜爱的DI框架，将一个MyDataRetriever实例注入到实际应用程序中的ClassToTest类构造函数中。|237848|entityMap^0|0|0|0|0|0|11|C|0|0|0|K|F|1C|B|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|15|8|@$O|16|P|17|Q|R]]|9|@]|A|$]]|$1|S|3|T|5|6|7|18|8|@]|9|@]|A|$]]|$1|U|3|V|5|F|7|19|8|@]|9|@]|A|$G|H]]|$1|W|3|X|5|6|7|1A|8|@$O|1B|P|1C|Q|R]|$O|1D|P|1E|Q|R]]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|Z|$]]

I would probably start by refactoring the code in order to make it more weakly coupled to an actual HTTP request. Right now this code seems to do quite a lot of things. 

This could be done by introducing an abstraction:

<pre><code>public interface IDataRetriever
{
 public byte[] RetrieveData(byte[] request);
}
</code></pre>

Now the class that you are trying to unit test could be decoupled from the actual HTTP request using the Inversion of Control design pattern:

<pre><code>public class ClassToTest
{
 private readonly IDataRetriever _dataRetriever;
 public Foo(IDataRetriever dataRetriever)
 {
 _dataRetriever = dataRetriever;
 }

 public string MethodToTest(string regularExpression, string strategy)
 {
 string body = CreateHttpBody(regularExpression, strategy);
 byte[] result = _dataRetriever.RetrieveData(Encoding.UTF8.GetBytes(body));
 return ExtractResponse(Encoding.UTF8.GetString(result));
 }
}
</code></pre>

It is no longer the ClassToTest's responsibility to deal with an actual HTTP request. It is now decoupled. Testing the <code>MethodToTest</code> becomes a trivial task.

And the last part obviously is to have an implementation of the abstraction that we have introduced:

<pre><code>public class MyDataRetriever : IDataRetriever
{
 private readonly string _url;
 public MyDataRetriever(string url)
 {
 _url = url;
 }

 public byte[] RetrieveData(byte[] request)
 {
 using (var client = new WebClient())
 {
 client.Headers[HttpRequestHeader.ContentType] = "text/plain; charset=utf-8";
 return client.UploadData(_url, request);
 }
 }
}
</code></pre>

You could then configure your favorite DI framework to inject a <code>MyDataRetriever</code> instance into the <code>ClassToTest</code> class constructor in your actual application.

blocks|key|2909503|text|如果模拟HttpWebRequest和HttpWebResponse变得太麻烦，或者如果你需要在验收测试中测试代码，你从“外部”调用你的代码，那么创建一个假的服务可能是最好的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2909504|我实际上编写了一个名为MockHttpServer的开源库来帮助实现这一点，这使得模拟任何通过HTTP进行通信的外部服务变得非常简单。|offset|length|2909505|下面是一个使用它和RestSharp一起调用API端点的示例，但是HttpWebRequest也可以很好地工作。|2909506|using+(new+MockServer(3333,+"/api/customer",+(req,+rsp,+prm)+=>+"Result+Body"))
{
++++var+client+=+new+RestClient("http://localhost:3333/");
++++var+result+=+client.Execute(new+RestRequest("/api/customer",+Method.GET));
}|code-block|syntax|javascript|2909507|在GitHub页面上有一个相当详细的自述文件，详细介绍了使用它的所有选项，并且可以通过NuGet获得该库本身。|2909508|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/jrharmon/MockHttpServer/^0|0|B|E|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@$D|Y|E|Z|1|10]]|A|$]]|$1|F|3|G|5|6|7|11|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|12|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

If mocking out the HttpWebRequest and HttpWebResponse becomes too cumbersome, or if you ever need to test code in an acceptance test, where you are calling your code from the "outside", then creating a fake service is probably the best way to go.

I actually wrote an open source library called <a href="https://github.com/jrharmon/MockHttpServer/" rel="noreferrer" title="MockHttpServer">MockHttpServer</a> to assist with this, making it super simple to mock out any external services that communicate over HTTP.

Here is an example of using it with RestSharp to call an API endpoint with it, but HttpWebRequest would work just as well.

<pre><code>using (new MockServer(3333, "/api/customer", (req, rsp, prm) =&gt; "Result Body"))
{
 var client = new RestClient("http://localhost:3333/");
 var result = client.Execute(new RestRequest("/api/customer", Method.GET));
}
</code></pre>

There is a fairly detailed readme on the GitHub page that goes through all the options available for using it, and the library itself is available through NuGet.

blocks|key|2909545|text|如果您乐于迁移到HttpClient+(一个官方的、可移植的、http客户端库)，那么不久前我写了一个名为MockHttp的库，它可能对您有所帮助。它提供了一个流畅的API，允许您为使用一系列属性匹配的请求提供响应。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2909546|entityMap|0|LINK|mutability|MUTABLE|url|https://nuget.org/packages/Microsoft.Net.http|1|https://github.com/richardszalay/mockhttp^0|8|A|0|1H|8|1|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]|$A|R|B|S|1|T]]|C|$]]|$1|D|3|-4|5|6|7|U|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]|L|$5|G|H|I|C|$J|M]]]]

If you're happy to move to <a href="https://nuget.org/packages/Microsoft.Net.http" rel="nofollow">HttpClient</a> (an official, portable, http client library), then I wrote a library a while back that may help called <a href="https://github.com/richardszalay/mockhttp" rel="nofollow">MockHttp</a>. It provides a fluent API that allows you provide responses for requests matched using a range of attributes.

I'm writing some code that calls a web service, reads back the response and does something with it. My code looks nominally like this:

<pre><code>string body = CreateHttpBody(regularExpression, strategy);

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(_url);
request.Method = "POST";
request.ContentType = "text/plain; charset=utf-8";

using (Stream requestStream = request.GetRequestStream())
{
 requestStream.Write(Encoding.UTF8.GetBytes(body), 0, body.Length);
 requestStream.Flush();
}

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
 byte[] data = new byte[response.ContentLength];

 using (Stream stream = response.GetResponseStream())
 {
 int bytesRead = 0;

 while (bytesRead &lt; data.Length)
 {
 bytesRead += stream.Read(data, bytesRead, data.Length - bytesRead);
 }
 }

 return ExtractResponse(Encoding.UTF8.GetString(data));
}
</code></pre>

The only parts where I am actually doing any custom manipulation is in the <code>ExtractResponse</code> and <code>CreateHttpBody</code> methods. However it feels wrong to just unit test those methods, and hope that the rest of the code comes together correctly. Is there any way I can intercept the HTTP request and feed it mock data instead?

EDIT This information is now out of date. It is much easier to construct this kind of code using the <a href="https://msdn.microsoft.com/en-us/library/system.net.http.httpclient(v=vs.118).aspx" rel="noreferrer">System.Net.Http.HttpClient</a> libraries.

Unit testing HTTP requests in c#

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我正在编写一些调用web服务、读回响应并对其执行某些操作的代码。我的代码名义上是这样的：string body = CreateHttpBody(regularExpression, strategy);HttpWebRequest request = (HttpWebRequest)WebRequest.Create...

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