coverlet/Documentation/Examples/MSBuild/MergeWith/HowTo.md

Run from solution root sln

To merge report togheter you need to run separate test and merge in one json format file. Last command will join and create final needed format file.

dotnet test XUnitTestProject1\XUnitTestProject1.csproj /p:CollectCoverage=true  /p:CoverletOutput=../CoverageResults/
dotnet test XUnitTestProject2\XUnitTestProject2.csproj /p:CollectCoverage=true  /p:CoverletOutput=../CoverageResults/ /p:MergeWith="../CoverageResults/coverage.json"
dotnet test XUnitTestProject3\XUnitTestProject3.csproj /p:CollectCoverage=true  /p:CoverletOutput=../CoverageResults/ /p:MergeWith="../CoverageResults/coverage.json" /p:CoverletOutputFormat="opencover"