Publish code coverage not finding coverage file in Azure DevOps

Question

I'm using Node 14.x and Jest 26.x. There is a npm test script in package.json file which contains the following:

cross-env NODE_ENV=test jest --coverage --forceExit

When I run it locally, it generates the code coverage report in ./coverage directory. The contents of ./coverage directory is as follows:

lcov-report (folder)
clover.xml
coverage-final.json
lcov.info

It looks like clover.xml contains code coverage report. There are more details which can be found in lcov-report folder. I've setup the Azure DevOps pipeline as follows for code coverage:

...
- task: PublishTestResults@2
  condition: succeededOrFailed()
  inputs:
    testRunner: JUnit
    testResultsFiles: '**/junit.xml'

# Publish code coverage results
# Publish Cobertura or JaCoCo code coverage results from a build
- task: PublishCodeCoverageResults@1
  inputs:
    codeCoverageTool: Cobertura
    summaryFileLocation: '$(System.DefaultWorkingDirectory)/coverage/clover.xml'

After running the pipeline, Azure DevOps doesn't seem to find the cover.xml file. I get the following error:

##[debug]Result: true
##[debug]Report directory: /home/vsts/work/_temp/cchtml
Reading code coverage summary from '/home/vsts/work/1/s/coverage/clover.xml'
##[warning]No coverage data found. Check the build errors/warnings for more details.
##[debug]Processed: ##vso[codecoverage.publish codecoveragetool=Cobertura;summaryfile=/home/vsts/work/1/s/coverage/clover.xml;reportdirectory=/home/vsts/work/_temp/cchtml;]

I also tried the following options for summaryFileLocation but all resulted in same error.

'**/coverage/clover.xml'
'$(System.DefaultWorkingDirectory)/**/coverage/clover.xml'

I understand that the format of clover.xml may not be the same as Cobertura or JaCoCo, but at least Azure should be able to locate the file. What I'm missing?

Answer 1

I've found a way accidentally.

It looks like Jest can generate cobertura coverage report. It needs to be added in Jest configuration. I've added the following in jest.config.js:

coverageReporters: ['text', 'text-summary', 'clover', 'cobertura']

Jest generated the cobertura coverage file in:

./coverage/cobertura-coverage.xml

Next I modified Azure pipeline file as follows:

- task: PublishCodeCoverageResults@1
  inputs:
    codeCoverageTool: Cobertura
    summaryFileLocation: '$(System.DefaultWorkingDirectory)/coverage/cobertura-coverage.xml'

After this changes, when I run the pipeline, Azure DevOps can find the file and show coverage report!