New dotnet test experience should support post-processing of artifacts

[Youssef1313]

@mariam-abdulla I think this is currently not implemented? (e.g, merging trx files).
I'm not sure what other post-processing VSTest was capable of.

[mariam-abdulla]

@mariam-abdulla I think this is currently not implemented? (e.g, merging trx files). I'm not sure what other post-processing VSTest was capable of.

VSTest is not capable of doing that as well. That's why this wasn't prioritized before the dogfooding.

[Youssef1313]

@mariam-abdulla Hmm, I thought this was already supported by vstest.console.exe via https://github.com/microsoft/vstest/blob/main/src/vstest.console/Processors/ArtifactProcessingPostProcessModeProcessor.cs

There are also some tests on SDK side: https://github.com/dotnet/sdk/blob/main/test/dotnet-test.Tests/GivenDotnetTestBuildsAndRunsArtifactPostProcessing.cs