Apartment(ApartmentState.STA) doesn't works together with Timeout

[reejk]

Apartment(ApartmentState.STA) doesn't works together with Timeout

I'm currently updating projects from .NET Framework (NUnit 3.10.1) to .NET 6 (NUnit 3.13.3) and found this problem. Real tests do some WPF relates stuff, so it requires STA apartment. The Timeout is used to prevent the test from running indefinitely when something goes wrong.

An example of minimalistic tests:

[TestFixture]
public class ApartmentTests
{
   [Test, Apartment(ApartmentState.STA), Timeout(1000)]
   public void SomeTestWithTimeout()
   {
      Console.WriteLine("SomeTestWithTimeout {0} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.GetApartmentState());
      Assert.Pass();
   }
   
   [Test, Apartment(ApartmentState.STA)]
   public void SomeTestWithoutTimeout()
   {
      Console.WriteLine("SomeTestWithoutTimeout {0} {1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.GetApartmentState());
      Assert.Pass();
   }
}

nunit3-console output:

NUnit Console 3.15.0 (Release)
Copyright (c) 2022 Charlie Poole, Rob Prouse
30 мая 2022 г. 21:21:19

Runtime Environment
   OS Version: Microsoft Windows 10.0.18362
  Runtime: .NET 6.0.4

Test Files
    .\TestProject1.dll

SomeTestWithoutTimeout 6 STA
SomeTestWithTimeout 8 MTA

[manfred-brands]

Timeout targeting anything other than .NETFramework is not safe (see #4021) and we have not found a solution for this.
The library has to create a new thread to run the test in and hope for the best as it cannot stop it (MS dropped Thread.Abort). This doesn't work with STA components created in a SetUp method. I suggest to refactor your test that they don't need Timeout at all.

[reejk]

The library has to create a new thread to run the test in and hope for the best as it cannot stop it

But why does it create a thread without a specified Apartment?
In my opinion, if Timeout can't really work on newer .NETs, it shouldn't break other things like Apartment.

Updated docs about this limitation and some runtime or compile-time checks would also be acceptable.

[TomEdwardsEnscape]

Timeout also breaks SingleThreaded for the same underlying reason: it always creates a new thread.

[OsirisTerje]

See comment here: #4658 (comment)