Selective proxy setting in WebTests

In developing a WebTest, I came across a scenario where I wanted a set of requests to use a proxy and another set of requests to bypass the proxy. A WebTest has a property named Proxy as shown in the figure below, which will be used by the Visual Studio Test Engine when sending out Http Requests.
In my WebTest, I wanted the 1st two WebRequests to bypass the proxy and the 3rd one to use a Proxy. Here I found it useful to create a WebTestRequestPlugin that is later associated with a WebRequest to set a proxy in the PreRequest method.


Here is the code for the WebTestRequestPlugin.

public class ProxySetter : WebTestRequestPlugin

{

    string proxy = null;

 

    public string Proxy

    {

        get

        {

            return this.proxy;

        }

        set

        {

            this.proxy = value;

        }

    }

 

    public override void PreRequest(object sender, PreRequestEventArgs e)

    {

        if (!String.IsNullOrEmpty(this.proxy))

        {

            e.WebTest.Proxy = this.proxy;

        }

        else

        {

            e.WebTest.Proxy = null;

        }

    }

}