Merging test coverage results when performing dotnet test solution.sln -p:CollectCoverage=true

[PeterKnealeBizCover]

Is it possible to merge the coverage results of all test projects in a solution
ie: Solution.sln contains multiple xunit test projects

dotnet test Solution.sln -p:CollectCoverage=true

The --merge-with parameter is mentioned in the below context but i dont know whether or if this can be applied to the above scenario

coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --merge-with "/path/to/result.json"

[tonerdo]

Coverlet doesn't currently support Solution wide executions. You'll need to run it for each project in the solution

[clairernovotny]

The approach I describe in #177 should work. You'll need to use a tool like ReportGenerator to merge the xml files.

In my Directory.Build.targets file, I have this:

  <PropertyGroup>
    <IsTestProject>$(MSBuildProjectName.Contains('Test'))</IsTestProject>
  </PropertyGroup>

  <PropertyGroup Condition="'$(IsTestProject)' == 'true'">
    <UseSourceLink>true</UseSourceLink>
    <CoverletOutputFormat>cobertura</CoverletOutputFormat>
    <Exclude>[xunit.*]*</Exclude>
    <CoverletOutput>$(MSBuildThisFileDirectory)coverlet/raw/$(AssemblyName)/$(TargetFramework)/</CoverletOutput>
  </PropertyGroup>

It then creates a subdirectory for each assembly and target framework, enabling me to run dotnet test with a wildcard.

[MarcoRossignoli]

Tracked by #357