Code coverage in Azure DevOps

Running the tests and collecting the code coverage

- task: DotNetCoreCLI@2
  displayName: 'Dotnet test'
  inputs:
    command: 'test'
    projects: '**/*Tests.csproj'
    arguments: '--configuration $(buildConfiguration) --filter "Traits!=Local&Traits!=Interactive" --collect:"XPlat Code Coverage"'
    publishTestResults: true

Getting code coverage using scripts

I’ve been using this way to do code coverage in Azure DevOps by using the dotnet CLI to install the ReportGenerator:

# Publish code coverage
- task: DotNetCoreCLI@2
  inputs:
    command: custom
    custom: tool
    arguments: install --tool-path . dotnet-reportgenerator-globaltool
  displayName: Install ReportGenerator tool

- script: 'reportgenerator -reports:$(Agent.TempDirectory)/**/coverage.cobertura.xml -targetdir:".coverlet" -reporttypes:"HtmlInline_AzurePipelines_Dark;Cobertura;lcov" -filefilters:"" -classfilters:"" -assemblyfilters:"-*.Tests"'
  displayName: 'Run code coverage ReportGenerator'

- task: PublishCodeCoverageResults@1
  displayName: 'Publish code coverage report'
  inputs:
    codeCoverageTool: Cobertura
    summaryFileLocation: '.coverlet/Cobertura.xml'
    reportDirectory: '.coverlet'

Using the ReportGenerator Azure DevOps extension

Another option is to install the Azure DevOps extension (https://marketplace.visualstudio.com/items?itemName=Palmmedia.reportgenerator)

# Publish code coverage
- task: reportgenerator@5
  displayName: Run code coverage report generator
  inputs:
    reports: '$(Agent.TempDirectory)/**/coverage.cobertura.xml'
    targetdir: '.coverlet'
    reporttypes: 'HtmlInline_AzurePipelines_Dark;Cobertura;lcov'
    filefilters: ''
    assemblyfilters: '-*.Tests'
    classfilters: ''

- task: PublishCodeCoverageResults@1  
  displayName: Publish code coverage report
  inputs:
    codeCoverageTool: Cobertura
    summaryFileLocation: '.coverlet/Cobertura.xml'
    reportDirectory: '.coverlet'

The trick to get dark mode to work

This is all well and good, but I never liked the light mode on the code coverage report as the contrast is painful on a poor developers eyes. But there is a way to get it published in dark mode. The last time I tried this I overlooked the need for the disable.coverage.autogenerate variable, which was required to get the HtmlInline_AzurePipelines_Dark theme to work:

variables:
  disable.coverage.autogenerate: 'true'

Refs: Daniel Palme’s ReportGenerator: https://github.com/danielpalme/ReportGenerator