Code coverage tab not showing in Azure DevOps - azure

Question

I have a relative simple test project under Azure DevOps and I want to generate code coverage.
This works... kinda. I get this:
I get the files I needed ( I think at least) But the tab is missing.
I have those three steps:
Do .NET test task
Install report generator
Run report generator to convert ( -reporttypes:HtmlInline_AzurePipelines;Cobertura")
publish result (s)
But the tab is not showing up? Any ideas?
- stage: Run_Unit_tests
jobs:
- job: 'Tests'
pool:
vmImage: 'windows-latest'
variables:
buildConfiguration: 'Release'
continueOnError: true
steps:
- task: DotNetCoreCLI#2
inputs:
command: custom
custom: tool
arguments: install --tool-path . dotnet-reportgenerator-globaltool
displayName: Install ReportGenerator tool
- task: DotNetCoreCLI#2
displayName: Test .NET
inputs:
command: test
projects: '**/*Test/*.csproj'
arguments: '--configuration $(buildConfiguration) --logger trx --collect:"XPlat Code Coverage"'
condition: succeededOrFailed()
- task: reportgenerator#4
inputs:
reports: '$(Agent.TempDirectory)\**\coverage.cobertura.xml'
targetdir: '$(Build.SourcesDirectory)\coverlet\reports'
verbosity: 'Verbose'
- task: PublishCodeCoverageResults#1
displayName: 'Publish code coverage'
inputs:
codeCoverageTool: Cobertura
summaryFileLocation: $(Build.SourcesDirectory)\coverlet\reports\Cobertura.xml
failIfCoverageEmpty: false
reportDirectory: $(Build.SourcesDirectory)\coverlet\reports\
I tried with code generator, without, enable code coverage variable or disable, tried with report generator and without...

Answer 1

I had the same problem, and just pressed F5 and it appeared!
It's mad, but it actually does it consistently.
It seems there's occasionally a bug in the devops front-end code?

Answer 2

You can try below yaml to publish code coverage.
First you need to make sure your project reference to nuget package coverlet.msbuild
<PackageReference Include="coverlet.msbuild" Version="2.5.1">
<PrivateAssets>all</PrivateAssets>
<IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
</PackageReference>
Then in your dotnet test task to enable CollectCoverage
arguments: '/p:CollectCoverage=true /p:CoverletOutput=$(Build.SourcesDirectory)\TestResult\ /p:CoverletOutputFormat=cobertura'
Then in reportgenerator task specify the reports folder to the CoverletOutput folder reports: '$(Build.SourcesDirectory)\TestResult\**\coverage.cobertura.xml'
Please check below yaml for reference:
steps:
- task: UseDotNet#2
inputs:
version: 2.2.x
- task: DotNetCoreCLI#2
inputs:
command: restore
projects: '**\*.csproj'
- task: DotNetCoreCLI#2
inputs:
command: custom
custom: tool
arguments: install --tool-path . dotnet-reportgenerator-globaltool
displayName: Install ReportGenerator tool
- task: DotNetCoreCLI#2
displayName: Test .NET
inputs:
command: test
projects: '**\*Test*.csproj'
publishTestResults: false
arguments: '--configuration $(buildConfiguration) /p:CollectCoverage=true /p:CoverletOutput=$(Build.SourcesDirectory)\TestResult\ /p:CoverletOutputFormat=cobertura'
condition: succeededOrFailed()
- task: reportgenerator#4
inputs:
reports: '$(Build.SourcesDirectory)\TestResult\**\coverage.cobertura.xml'
targetdir: '$(Build.SourcesDirectory)\coverlet\reports'
verbosity: 'Verbose'
condition: succeededOrFailed()
- task: PublishCodeCoverageResults#1
displayName: 'Publish code coverage'
inputs:
codeCoverageTool: Cobertura
summaryFileLocation: $(Build.SourcesDirectory)\coverlet\reports\Cobertura.xml
failIfCoverageEmpty: false
reportDirectory: $(Build.SourcesDirectory)\coverlet\reports\
condition: succeededOrFailed()
You can also refer to this blog.

Answer 3

I had this issue too and tracked it down to having a mixture of VS Test and dotnet test tasks in my pipeline. Once I removed the VS Test task it all worked.
It seems the VS Test task uploads its own code coverage results and the combination of publishing cobertura results + this VS Test task confused Azure Devops.