Azure DevOps Code Coverage for .NET Core 3.1

Question

I am setting up an Azure DevOps pipeline for an ASP.NET Core 3.1 Application and I have the following YAML definition test segment) for building, testing and code coverage.

      - task: DotNetCoreCLI@2
        displayName: "dotnet global test tool install"
        inputs:
          command: 'custom'
          custom: 'tool'
          arguments: 'install --global dotnet-reportgenerator-globaltool'

      - task: DotNetCoreCLI@2
        displayName: "dotnet test"
        inputs:
          command: 'test'
          projects: '**/*[Tt]ests'
          arguments: '--no-build --configuration $(buildConfiguration) /p:CollectCoverage=true /p:CoverletOutputFormat=cobertura /p:CoverletOutput=$(System.DefaultWorkingDirectory)/TestResults/Coverage'
          testRunTitle: 'Unit Test'
          workingDirectory: '$(System.DefaultWorkingDirectory)'
      - script: reportgenerator -reports:$(System.DefaultWorkingDirectory)/**/cobertura/coverage.xml -targetdir:$(System.DefaultWorkingDirectory)/CodeCoverage -reporttypes:HtmlInLine_AzurePipelines
        displayName: "create code coverage report"


      - task: PublishCodeCoverageResults@1
        displayName: "publish test coverage result"
        inputs:
          codeCoverageTool: 'Cobertura'
          summaryFileLocation: '$(System.DefaultWorkingDirectory)/**/cobertura/coverage.xml'

Upon running in Azure DevOps, I get the following error

What could I be doing wrong? Project Source: GitHub

Answer 1

Finally got it working with the help of a Microsoft MVP. Sharing the code from the test segment that worked.

     - task: DotNetCoreCLI@2
        displayName: "dotnet global test tool install"
        inputs:
          command: 'custom'
          custom: 'tool'
          arguments: 'install --global dotnet-reportgenerator-globaltool'

      - script: dotnet test WebApp.Web.Tests/WebApp.Web.Tests.csproj --logger "trx;LogFileName=testresults.trx" /p:CollectCoverage=true /p:CoverletOutputFormat=cobertura /p:CoverletOutput=$(Build.SourcesDirectory)/TestResults/Coverage/
        displayName: 'dotnet test'

      - script: reportgenerator "-reports:$(Build.SourcesDirectory)/TestResults/Coverage/coverage.cobertura.xml" "-targetDir:$(Build.SourcesDirectory)/TestResults/Coverage/Reports" -tag:$(Build.BuildNumber) -reportTypes:htmlInline
        workingDirectory: $(Build.SourcesDirectory)/WebApp.Web.Tests
        displayName: 'dotnet reportgenerator'
      - task: PublishTestResults@2
        inputs:
          testRunner: VSTest
          testResultsFiles: '**/*.trx'
          failTaskOnFailedTests: true

      - task: PublishCodeCoverageResults@1
        inputs:
          codeCoverageTool: 'cobertura'
          summaryFileLocation: $(Build.SourcesDirectory)/TestResults/Coverage/**/coverage.cobertura.xml
          reportDirectory: $(Build.SourcesDirectory)/TestResults/Coverage/Reports
          failIfCoverageEmpty: false 

Resources that helped can be found here