Verify `--results-directory` with new `dotnet test` and document potential difference compared to VSTest

[Youssef1313]

I think in VSTest, when using a relative path as value of --results-directory, it will be considered relative to the working directory of the running .NET CLI (usually repo root).

In MTP, it will be passed as-is to each executable, and will be relative to the working directory of each executable, which is the directory containing the executable (e.g, bin directory), unless RunWorkingDirectory is overwritten.

We need to verify the above behavior, and if there is indeed a difference in this case between MTP and VSTest, we should clearly document it.

[nohwnd]

There is a difference, and there is even difference between how vstest.console and dotnet test (with vstest and sln / csproj) works IIRC. Vstest.console will take the location from which it was started, while dotnet test will take the root of the project? or something like that.

For that reason MTP is placing the test results right next to the executable, to keep it consistent among runs, and consistent with running the exe directly.

[Youssef1313]

I think it's good to document this then.