visual studio web测试错误处理

Question

I'm using Visual Studio Ultimate 2013 and have a load test that uses a web test with a number of request and web test plugins.

In my PostRequest plugin, I'm checking the http status code of the response and am flagging an error in a WebTest.Context parameter, when a hhtp code of over 400 is returned. What I want to do is pick this up in the PostTransaction WebTest plugin and update a database table. The problem is, that the test aborts when the framework detects the error and the PostTransaction plugin isn't called.

I've added a PostWebTest plugin, that I thought would be called when the test iteration aborted, but it's never hitting this when a request fails. It does hit it if the test is successful. What am I missing?

public override void PostRequest(object sender, PostRequestEventArgs e)
{
    ...
    statusCode = e.Response.StatusCode.GetHashCode();
    If (statusCode > 400)
    {
        e.WebTest.Context["TransactionFailCount"] = 1;
    }
}

public override void PostTransaction(object sender, PostTransactionEventArgs e)
{
    int transactionFailCount = Convert.ToInt32(e.WebTest.Context["TransactionFailCount"]);
    if (transactionFailCount > 0)
        failCount = 1;
    else
        passCount = 1;
    ...
    base.PostTransaction(sender, e);

 }

 public override void PostWebTest(object sender, PostWebTestEventArgs e)
 {
     base.PostWebTest(sender, e);
 }

Thanks

Answer 1

A Web Performance Test (WPT) will continue to execute after an error is detected unless the Stop on error property of the test is true . It is possible that some aspects of a the handling of a request are not performed after an error, but I have not seen any such cases.

Be careful of terminology. WPTs use "transactions" as a way of grouping several requests. The context (right click) menu of a request has an "Add transaction" entry that selects a range of items in the test to be included in that transaction. Perhaps you should be using the PostRequest or PostPage plugins rather than PostTransaction .

I recommend that you do some experiments with a simple two or three request WPT plus some simple plugins that just announce that they have been called. For example

public override void PostRequest(object sender, PostRequestEventArgs e)
{
    e.WebTest.AddCommentToResult("PostRequest called for url " + e.Request.Url);
}

Additionally, there is a good explanation of how and when plugins are called in pages 32 to 44 of the Visual Studio Performance Testing Quick Reference Guide from Codeplex.

The statement statusCode = e.Response.StatusCode.GetHashCode(); is strange. The value of e.Response.StatusCode is an enum , it integer value can be obtained by casting. The GetHashCode method is not intended to get the numeric value of an enum . The statement would be better as statusCode = (int)e.Response.StatusCode; or the assign and test (note that if is used for conditionals in C#, not If ) might be better as

statusCode = e.Response.StatusCode;
if ( e.Response.StatusCode >= System.Net.HttpStatusCode.BadRequest ) { ... }