Inconsistent test failure in GlobalSettingsTests

[MiYanni]

Summary

It seems that the GlobalSettings is designed in a way where it doesn't clean up properly. The tests for it fail intermittently:

Unhandled exception. System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'GlobalSettings'.
   at Microsoft.TemplateEngine.Edge.BuiltInManagedProvider.GlobalSettings.GetInstalledTemplatePackagesAsync(CancellationToken cancellationToken) in /_/src/Microsoft.TemplateEngine.Edge/BuiltInManagedProvider/GlobalSettings.cs:line 70
   at Microsoft.TemplateEngine.Edge.UnitTests.GlobalSettingsTests.<>c__DisplayClass3_0.<<TestFileWatcher>b__0>d.MoveNext() in /_/test/Microsoft.TemplateEngine.Edge.UnitTests/GlobalSettingsTests.cs:line 54
--- End of stack trace from previous location ---
   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_1(Object state)
   at System.Threading.QueueUserWorkItemCallback.Execute()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()

If you look at the TestFileWatcher test, to explain what it does in English:

• Creates 2 instances of GlobalSettings that point to the same settings file.
• Sets a SettingsChanged event for the second instance using a TaskCompletionSource that retrieves an installed template package
• The first instance creates template package data and sets it
• The test waits until the TaskCompletionSource finishes, asserts that it didn't time out, and checks to see that the template package data from the task is correct

Now, somehow, the error above seems to indicate that the second instance of GlobalSettings no longer exists when the SettingsChanged event is fired. This instance is scoped to the lifetime of the test method. Maybe the event is fired a second time? Maybe there is something else going on with Dispose that I'm unaware of?

This happened on 2 different PRs that I've observed so far. It happened (in both) on the Linux Debug job for the PR.

Logs

• Microsoft.TemplateEngine.Edge.UnitTests_net9.0_x64.log
• Microsoft.TemplateEngine.Edge.UnitTests_net9.0_x64 (1).log

[MiYanni]

Another failure but in the OSX Release job:

Unhandled exception. System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'GlobalSettings'.
   at Microsoft.TemplateEngine.Edge.BuiltInManagedProvider.GlobalSettings.GetInstalledTemplatePackagesAsync(CancellationToken cancellationToken) in /_/src/Microsoft.TemplateEngine.Edge/BuiltInManagedProvider/GlobalSettings.cs:line 70
   at Microsoft.TemplateEngine.Edge.UnitTests.GlobalSettingsTests.<>c__DisplayClass3_0.<<TestFileWatcher>b__0>d.MoveNext() in /_/test/Microsoft.TemplateEngine.Edge.UnitTests/GlobalSettingsTests.cs:line 54
--- End of stack trace from previous location ---
   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_1(Object state)
   at System.Threading.QueueUserWorkItemCallback.Execute()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()
   at System.Threading.Thread.StartCallback()

Log: Microsoft.TemplateEngine.Edge.UnitTests_net9.0_x64 (2).log