test: Mark test projects as AOT compatible and switch to xunit.v3.aot with MTP testrunner

[OleRoss]

This is the first step to introduce the fixes necessary for #293.

The final goal is to add DisableRuntimeMarshalling to all the test projects. However, when I did that, additional issues arose from, e.g., function pointers that depended on runtime marshaling as well, not just the Vec<T> use case in #293.

Therefore, I decided to split the work into multiple smaller PRs and start with a common foundation: The AOT-compatible test project.

I migrated to xunit.v3.aot (still in prerelease) and fixed some warnings. The AOT package requires the new MicrosoftTestingPlatform, which is why some of the dotnet test commands were adjusted.

Note: I did not want to change the CI, so the tests still run normally in the CI. I only published and ran them locally.

[ralfbiedert]

What is this?

[OleRoss]

This configures the dotnet test to use the new MTP runner.

{
  "test": {
    "runner": "Microsoft.Testing.Platform"
  }
}

You can find the related documentation from Microsoft here.

From what I understand from the xunit.v3 aot docs, it should be possible to continue using VSTest, but since it's the default, I think it makes sense to use MTP all the way.

Edit: I tried to move it into the C# crate, but if you run dotnet test from the repo root, it has no effect, so it should stay there, unfortunately.

[ralfbiedert]

Ah, actually, would it work wrapping the C# runner via a just command and then make it pick up the file from a C#-related path?

[OleRoss]

you mean moving the global.json file to crates/backend_csharp and then modifying the just file to

    cd crates/backend_csharp && dotnet test --project tests/reference_project/Tests/Tests.csproj

? That should be possible as well, I think

[ralfbiedert]

Yes, something to the effect. I think it's ugly if a random backend litters the crate root for unit tests.

[ralfbiedert]

Thanks!

[ralfbiedert]

I migrated to xunit.v3.aot (still in prerelease) and fixed some warnings. The AOT package requires the new MicrosoftTestingPlatform, which is why some of the dotnet test commands were adjusted.

FYI, this seems to have broken Rider unit testing; no unit tests are detected anymore for me, e.g., here should be a "Run Test" marker:

[OleRoss]

Hi, can you try to "Enable Testing Platform support"?

It works for me

[ralfbiedert]

Yes, worked, thanks a lot!