System.ArgumentException occurs on StateMachine.NET.UnitTest

[cozzyy2002]

Describe the bug
System.ArgumentException occurs when StateMachine.NET.UnitTest runs.

[2019/12/07 23:09:44 Informational] ------ Run test started ------
[2019/12/07 23:09:45 Informational] NUnit Adapter 3.15.1.0: Test execution started
[2019/12/07 23:09:45 Informational] Running selected tests in C:\Users\cozzy\source\repos\tsm\StateMachine.NET.UnitTest\bin\Debug\StateMachine.NET.UnitTest.dll
[2019/12/07 23:09:45 Informational]    NUnit3TestExecutor converted 1 of 1 NUnit test cases
[2019/12/07 23:09:53 Error] アクティブなテストの実行が中止されました。理由: ハンドルされていない例外: System.ArgumentException: AppDomain 間で GCHandle を渡すことはできません。
パラメーター名:handle
   場所 System.Runtime.InteropServices.GCHandle.InternalCheckDomain(IntPtr handle)
   場所 System.Runtime.InteropServices.GCHandle.FromIntPtr(IntPtr value)
   場所 System.Runtime.InteropServices.GCHandle.op_Explicit(IntPtr value)
   場所 gcroot<tsm_NET::State::ExitDelegate ^>.{dtor}(gcroot<tsm_NET::State::ExitDelegate ^>* ) 場所 c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.16.27023\include\msclr\gcroot.h:行 89
   場所 native.Callback<tsm_NET::State::ExitDelegate,long (__stdcall*)(tsm::IContext *,tsm::IEvent *,tsm::IState *)>.{dtor}(Callback<tsm_NET::State::ExitDelegate\,long (__stdcall\*)(tsm::IContext \*\,tsm::IEvent \*\,tsm::IState \*)>* )
   場所 native.State.{dtor}(State* )
   場所 native.State.__vecDelDtor(State* , UInt32 A_0)

[2019/12/07 23:09:53 Informational] ========== Run test finished: 0 run (0:00:09.210603) ==========
[2019/12/07 23:16:10 Informational] ------ Discover test started ------
[2019/12/07 23:16:11 Informational] ========== Discover test finished: 0 found (0:00:00.6042904) ==========

To Reproduce
Steps to reproduce the behavior:

1. Check-out branch feature-memory-check
2. Comment out the code that calls AddRef/Release methods of tsm_NET::State and tsm_NET::Event.
   • These codes are intended to release memories when the objects becomes not referenced.
   • But Adding reference count of State/Event object causes mutual reference of Managed object and Native object.
   • Then uncommenting out the code leads:
     • Unit test succeeds.
     • Though State/Event object is NOT released.
3. Build project StateMachine.NET.UnitTest.
4. Run a test case.

Expected behavior
No exception occurs and Test succeeds.

Desktop (please complete the following information):

• OS: Windows 10 Pro version 1909

Additional context

[cozzyy2002]

I've found a way to run unit test using nunit3-console.exe as follows.
But when unit test runs on test explorer of Visual Studio, the exception occurs.

The exception occurs when native State(or Event) deletes managed object associated with it.

• Native object runs on default AppDomain.
• Managed object runs on secondary AppDomain.

To avoid above situation, unit test should run on a single AppDomain.

NUnit console runner accepts command line option --domain=None.
See Console Command Line - nunit / docs.
As of nunit3, test assembly and all nunit assemblies should be in the same directory for --domain=None option to work.
See nunit/nunit#1741

To run unit test in debug mode:

• Append command line option --pause.
• Attach to unit test process after executing nunit console.

[cozzyy2002]

Now working on branch bugfix-0008-dispatch-on-managed-thread so that unit test can run on test explorer of Visual Studio.

[cozzyy2002]

Fixed by PR #10.