Unable to disable determistic source mapping in Microsoft.CodeCoverage

[bh-sijtnic]

Description

After upgrading our build tools to 17.10, we started seeing .msCoverageSourceRootsMapping_testassembly files in a subfolder of our output folder.
We managed to trace these files back to the Microsoft.CodeCoverage package, where the MsCoverageReferencedPathMaps target was introduced.
#4849

This target always runs when build, it does not allow the user to disable it.

1. Why are these files needed during the build if code coverage is not required? I don't want them if they are not needed.
2. The location where the files are stored cannot be controlled. In our environment, the files appear in a strange location "bin\debug\net6.0-windows10.0.19041\net6.0-windows10.0.19041\win-x64", while the test assembly itself is in "bin\debug\net6.0-windows10.0.19041". Not sure why the files end up in the wrong subfolder... looking at the code it should be using $(OutputPath). It would be good to add the option to override this path.
3. Nowhere in the (normal verbosity) build logs i could these files being generated.
4. We dont even use the Microsoft.CodeCoverage NuGet package. Which package pulls this in?

Steps to reproduce

Create a class library and a unit test project with a test. Build the projects and notice the .msCoverageSourceRootsMapping_TestProject2 being generated in the output folder.

Expected behavior

1. I expect properties are available that allow me to disable this functionality
2. I expect i have the option to set a property to override the rootPath used to write these files
3. I expect the tasks have some output to the log files
4. I dont even expect the Microsoft.CodeCoverage NuGet package to be used, it is not visible in my Visual Studio solution explorer

Actual behavior

Undesired files are written and i have no way to monitor and control this.

Environment

We have multiple .NET projects using

• Visual Studio 2022 LTSC 17.10

• .NET 6 SDK 6.0.424

• Relevant packageReferences

    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
    <PackageReference Include="MSTest.TestAdapter" Version="2.2.10" />
    <PackageReference Include="MSTest.TestFramework" Version="2.2.10" />
  

[nohwnd]

@fhnaseer please have a look.

[fhnaseer]

Microsoft.CodeCoverage is added as a dependency of Microsoft.NET.Test.Sdk. @jakubch1 can you please have a look into this?

[bh-sijtnic]

@fhnaseer, thank you for fixing our biggest problem with this target.
While making changes, may i suggest you add an option to overwrite/correct the targetdir as well?

As i mentioned in point 2, in our case the files do not end up next to the assembly, but 2 levels deeper, something clearly is going wrong there. For us it would work if we can override the root dir that is used in the _msCoverageSourceRootMappingFilePath property.

[KirillOsenkov]

What are these files for? I notice our build is slow because of MsCoverageReferencedPathMaps.

Is it safe to turn off?

@fhnaseer is there any documentation on this anywhere?

[KirillOsenkov]

Also this target runs during Design-time build. I think we should turn if off if $(DesignTimeBuild) is set.

[fhnaseer]

Is it safe to turn off?

@KirillOsenkov Yes, you can turn these off. Can you please check binlogs to see how much time these tasks are taking?

[KirillOsenkov]

when I turned it off, our build went down from 1:50 -> 1:30, so 20 seconds was spent here. We have 450 referenced projects