0% coverage reported on netfx target

Migrating this issue over from https://github.com/tonerdo/coverlet/issues/578 comments

When running tests locally, I get correct results with netfx target on 32-bit

dotnet test tests\Blake2.Test -c Coverage -s tests\runsettings --logger trx

with the following runsettings:

<RunSettings>
    <RunConfiguration>
        <TargetPlatform>x86</TargetPlatform>
        <DisableAppDomain>true</DisableAppDomain>
    </RunConfiguration>
</RunSettings>

However, if I switch to <TargetPlatform>x64</TargetPlatform>, I get 0% coverage.

On Azure Pipelines, I get 0% coverage under either config.

The netcore targets are correct no matter how I run.

I have tried the coverlet.collector workarounds from https://github.com/tonerdo/coverlet/blob/master/Documentation/KnowIssues.md#2-upgrade-coverletcollector-to-version--100 with no change in results.

My current config can be found here: https://github.com/saucecontrol/Blake2Fast/tree/azure-coverage

And the updated cmdline I’m using with coverlet.collectors is

dotnet test tests\Blake2.Test -c Coverage -s tests\runsettings.collector --logger trx --collect:"XPlat Code Coverage"

[saucecontrol]

It’s no problem at all. I just wanted to try it out before 3.0 lands since I had a free minute. Tried the private feed 3.0.0-preview.1, and it’s working great now. Thanks much!

[MarcoRossignoli]

I did a test and found the issue, is related to coverlet in-proc load failure, vstest plat try to load netcoreapp2.1 lib inside a netfx process and fails

TL;DR; msbuild/.net tool suffer a know issue https://github.com/tonerdo/coverlet/blob/master/Documentation/KnowIssues.md#1-vstest-stops-process-execution-earlydotnet-test So we use collector because in that way in-proc coverlet collector class is injected inside test host process and we can persist hit file. In-proc collector is integrated and communicate with vstest platform(datacollector process talk with host process and wait to kill until “they agree”).

Now the issue is that in-proc coverlet collector was written with netcoreapp2.1 tfm(I asked to vstest team why, they wrote it) so when vstest plat try to load it a lot of ref failure happens

TpTrace Warning: 0 : 31440, 5, 2020/02/16, 17:39:16.357, 1014902001697, testhost.x86.exe, TestPluginDiscoverer: Failed to get types from assembly 'coverlet.collector, Version=1.2.0.0, Culture=neutral, PublicKeyToken=4beb1ad7f05a1c71'.  Skipping test extension scan for this assembly.  Error: System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.RuntimeModule.GetTypes()
   at System.Reflection.Assembly.GetTypes()
   at Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework.TestPluginDiscoverer.GetTestExtensionsFromAssembly[TPluginInfo,TExtension](Assembly assembly, Dictionary`2 pluginInfos)
TpTrace Warning: 0 : 31440, 5, 2020/02/16, 17:39:16.357, 1014902004338, testhost.x86.exe, LoaderExceptions: System.IO.FileNotFoundException: Could not load file or assembly 'System.Runtime, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
File name: 'System.Runtime, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
   at Microsoft.VisualStudio.TestPlatform.Common.ExtensionFramework.TestPluginCache.CurrentDomainAssemblyResolve(Object sender, AssemblyResolveEventArgs args)
   at Microsoft.VisualStudio.TestPlatform.PlatformAbstractions.PlatformAssemblyResolver.AssemblyResolverEvent(Object sender, Object eventArgs)
   at System.AppDomain.OnAssemblyResolveEvent(RuntimeAssembly assembly, String assemblyFullName)
...

When this happen and vstest plat kill process we suffer again of know issue above so we cannot persist hit file…and this is randomic, I mean can happen for x64 and not for x86 and vice-versa.

TpTrace Verbose: 0 : 25296, 1, 2020/02/16, 17:39:17.847, 1014916892926, datacollector.dll, [coverlet]Hits file:'...\SauceControl.Blake2Fast_225870d7-66fa-4f8a-91e3-e11c8ef43af2' not found for module: 'SauceControl.Blake2Fast'

I did some test with a collector compiled for netstandard2.0+vstest master compiled plat and it works…btw I found also a past statement of vstest team https://github.com/tonerdo/coverlet/issues/466#issuecomment-501158913 so the past idea was support only netcoreapp, but now that we have an unsolvable issue with automatic process kill(above know issue) maybe we should change the idea…or abandon netfx(try msbuild and if you hit issue above…no solution) I’ll wait vstest team thinking.