System.Reflection.Metadata version mismatch unable to find file System.Reflection.Metadata,Version=1.4.3.0

[vagisha-nidhi]

I am trying to load coverlet into a datacollector which would collect coverage and report back the results to TestPlatform. The issue with loading coverlet APIs is that coverlet.core depends on System.Reflection.Metadata, AssemblyVersion : 1.4.3.0 and the datacollector process (in which it is being loaded) has a dependency on System.Reflection.Metadata, AssemblyVersion=1.4.2.0

This results in System.Reflection.Metadata, AssemblyVersion=1.4.2.0 being loaded and coverlet erroring out with System.IO.FileLoadException: Could not load file or assembly 'System.Reflection.Metadata, Version=1.4.3.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. Could not find or load a specific file.

This can be resolved with lowering down the version of System.Reflection.Metadata.

I am a Software Engineer on the TestPlatform team and can raise a PR to address the issue.

[MarcoRossignoli]

I am trying to load coverlet into a datacollector which would collect coverage and report back the results to TestPlatform.

Can you elaborate the scenario?We have some work in place to use coverlet with data collector to fix issue where test plat kill process before we can save instrumentation report file to disk #329

[vagisha-nidhi]

@MarcoRossignoli
We have written an outproc datacollector that references coverlet.core.dll. This calls into coverlet APIs such as coverage.PrepareModules(), coverage.GetCoverageResult(). We get coverage results thus and send these back to testplatform using DataCollectionSink.

The issue I have already mentioned is that datacollector has a dependency on Microsoft.TestPlatform.ObjectModel here which has a dependency on System.Reflection.Metadata, AssemblyVersion=1.4.2.0 here. Due to the datacollector dependency, System.Reflection.Metadata, AssemblyVersion=1.4.2.0 is already loaded and coverlet errors out saying it cannot find System.Reflection.Metadata, AssemblyVersion=1.4.3.0, since it is unable to load System.Reflection.Metadata again.
#329 is a different issue.

[MarcoRossignoli]

Understood, apart from this issue I'm warning you that we're working on internals to allow better testability and I don't guarantee that "internal api" like coverage.PrepareModules() coverage.GetCoverageResult() will be untouched, to achieve this cc @tonerdo

[tonerdo]

@vagisha-nidhi like @MarcoRossignoli mentioned the coverlet.core API is subject to change on a whim. Out of curiosity, are you using an unofficial NuGet or a local build of coverlet.core?

[vagisha-nidhi]

@tonerdo Yeah. Noted the warning. I have been using a local build of coverlet.core (setting hintpath to coverlet.core dll).

[MarcoRossignoli]

fixed in #392