RunSettingsFilePath property isn't honored by VSTest

[ViktorHofer]

The property RunSettingsFilePath which points to the local .runsettings file for the test session should be honored by VSTest and not just by Visual Studio. Doc that points to that property: https://docs.microsoft.com/en-us/visualstudio/test/configure-unit-tests-by-using-a-dot-runsettings-file?view=vs-2019#visual-studio-2019-version-164-and-later

We need this in the runtime repo (converged repo of coreclr, corefx and core-setup) to configure our test sessions without always needing to type the path to the runsettings file. Our end-goal is that dotnet test is sufficient to run our tests.

cc @ManishJayaswal @singhsarab

[nohwnd]

A simple repro for this is to have a MSTest test project with a single inconclusive test and force the inconclusive state to translate to fail via run settings. This will give a failing test when settings are picked up and a skipped test when they are not.

using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace UnitTestProject1
{
    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void TestMethod1()
        {
            Assert.Inconclusive();
        }
    }
}

Add the following example.runsettings in your solution folder

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
  <MSTest>
    <MapInconclusiveToFailed>True</MapInconclusiveToFailed>
  </MSTest>
</RunSettings>

and configure the project to pick up the settings file by adding this to your csproj:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp2.1</TargetFramework>

    <IsPackable>false</IsPackable>

+    <RunSettingsFilePath>$(SolutionDir)\example.runsettings</RunSettingsFilePath>
  </PropertyGroup>

Now running it via Test runner will report the test as failed, while running it via dotnet test will report the test as skipped.

[vritant24]

This issue is currently being discussed here #2229