In the previous .Net version, ASP.Net seemed to generate a very simple function of the form of __doPostBack([targetId], [targetArguments]) that would effectively set two hidden variables (__EVENTTARGET and __EVENTARGUMENT respectively). In the current version, ASP.Net generates a much more complex javascript function (called WebForm_DoPostBackWithOptions) that I think is caused with use of any of the ASP validator components.

One work around that one person (Lance Ahlberg) found was to turn the “CausesValidation” property off for controls but this may or may not suit the way that you are developing your website. Looking at what the javascript generated does, I think that there must have been a better solution so I spent some time delving into the depths of NUnit ASP to find one.

The result is a patch to ControlTester.cs that allows the __EVENTTARGET and __EVENTARGUMENT to still be set by extracting out the appropriate values from the new WebForm_DoPostBackWithOptions javascript function. You can download the patch here but you have to build your own NUnit ASP, or wait until this is integrated with the next release. The ticket for my submission can be found here.