TestTfmsInParallel:false is not works when running tests on TestExplorer with Microsoft.Testing.Platform mode

[filzrev]

Describe the bug

I'm using <TestTfmsInParallel>false</TestTfmsInParallel> setting to disable parallel execution between TargetFrameworks.

But when running tests on Visual Studio Test Explorer with Microsoft.Testing.Platform mode.
It not works as expected.

Steps To Reproduce

1. Create test project with dotnet new mstest --sdk --test-runner MSTest
2. Modify csproj file with following changes
   2.1 Set target frameworks to <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   2.2. Set <TestTfmsInParallel>false</TestTfmsInParallel>
3. Add Thread.Sleep(5000); code to test method.
4. Open Visual Studio and build project.
5. Run test with Test Explorer. And confirm test is executed in parallel.

Expected behavior

Tests are executed in sequential orders.

Actual behavior

Tests are executed in parallel between targe frameworks.

Tested environment

• Visual Studio 2022 Version 17.12.0
  (With preview feature Use testing platform server mode to use Microsoft.Testing.Platform)

Additional context

When tests are executed with <UseVSTest>true</UseVSTest>. It works as expected.

[campersau]

I have the same issue. I always need to switch the TargetFramework manually in the csproj so there is only one when using test explorer...

[Evangelink]

Hi!

Thanks for raising this. I was not aware of the existance of this property!

It looks like this is an issue on Test Explorer side so I have created a ticket on Developer community (https://developercommunity.visualstudio.com/t/TestTfmsInParallel:false-does-not-work-w/10817302). I'll move ahead and close this one.