DataCollector in ".runsettings" file does not get injected into the test host process

[caghand]

Description

When running dotnet test, if I specify a DataCollector using the command line, the in-process collector will be injected. But if I specify a DataCollector using a ".runsettings" file, the in-process collector won't be injected.

Steps to reproduce

Good case:
dotnet test <path_to_csproj_file> --collect "XPlat Code Coverage"

• coverlet.collector gets injected into the test host process, and there are no problems.

Bad case:
dotnet test <path_to_csproj_file> --settings test.runsettings
(test.runsettings contains a DataCollector element with friendlyName="XPlat Code Coverage".)

• coverlet.collector still works, but because it doesn't get injected into the test host process, the following issue is encountered: https://github.com/coverlet-coverage/coverlet/blob/master/Documentation/KnownIssues.md#1-vstest-stops-process-execution-earlydotnet-test

Environment

.NET Core 3.1

[jakubch1]

Coverlet is not standard data collector. It is InProcess data collector which requires additional InProcDataCollector tag. I was able to run it correctly with below run settings.

  <DataCollectionRunSettings>
    <DataCollectors>
      <DataCollector friendlyName="XPlat Code Coverage" enabled="True" />
    </DataCollectors>
  </DataCollectionRunSettings>
  <InProcDataCollectionRunSettings>
    <InProcDataCollectors>
      <InProcDataCollector assemblyQualifiedName="Coverlet.Collector.DataCollection.CoverletInProcDataCollector, coverlet.collector, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" friendlyName="XPlat Code Coverage" enabled="True" codebase="C:\Users\UseThisAccount\.nuget\packages\coverlet.collector\3.0.3\build\netstandard1.0\coverlet.collector.dll" />
    </InProcDataCollectors>
  </InProcDataCollectionRunSettings>

The issue will be gone when coverlet will keep results in shared memory. In such case in process data collector is not needed.
I hope it will be resolved by: coverlet-coverage/coverlet#808.