TestDriven.NET and STA

I think I've run into a...well, it's not really a bug (but I wouldn't call it a feature) with TestDriven.NET. The problem is when a method that's somewhere in the call stack of the test method calls WaitHandle.WaitAll(WaitHandle[]). Since the add-in uses STAThreadAttribute on its' main method, I get a NotSupportedException with the following message:

TestCase 'xxx.xxx.QueryMultipleServers' failed: System.NotSupportedException : WaitAll for multiple handles on an STA thread is not supported.

It's interesting to note, thought, that the test does not fail under NUnit's GUI, even though its' main method is also marked with STAThreadAttribute. It may have something to do with the add-in running under VS .NET. It's confusing, that's for sure. If I can find a rational explanation for this I'll let you know. If you want to try it out for yourself, just use this code:

using NUnit.Framework;
using System;
using System.Threading;

namespace WaitHandlesAndSTA
    public sealed class HandleTest
        public void WaitForHandles()
            WaitHandle[] handles = new WaitHandle[4];

            for(int i = 0; i < handles.Length; i++)
                handles[i] = new AutoResetEvent(true);


In NUnit (I'm using 2.2), I get a green bar. In TestDriven.NET (under VS .NET 2003), I get the exception.

Update #1: I just noticed that in NUnit, the ApartmentState property for the current Thread is MTA, and in TestDriven.NET it's STA. At least that explains the difference...

Update #2: Seems like NUnit has a way to specify ApartmentState. In the constructor for TestRunnerThread, it checks the configuration file for different apartment state settings. For some reason I can't get the EXE's configuration file to recognize the entries that are in nunit.tests.dll.config such that I can change the apartment state that TestRunnerThread uses.

* Posted at 02.08.2005 02:51:42 PM CST | Link *

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