How to publish Jest Unit Test Results in VSTS tests?

I’ve used a different approach, b/c after some research I found that the Jest testResultsProcessor property is deprecated. I’m using the jest-junit package for test reports (which has been worked on more recently than the jest-trx-results-processor, fwiw):

1. Add jest-junit to package.json

   Eg yarn add -D jest-junit or npm add --save-dev jest-junit

2. Add a VSTS task to run Jest using the jest-junit results reporter

   I used the Yarn task, but you can alternately use the npm task. I used these task arguments:

   jest --ci --reporters=jest-junit --reporters=default --coverage --coverageReporters=cobertura --coverageReporters=html
   

   because I also wanted code coverage. To skip code coverage reporting, use these (npm or yarn) task arguments:

   jest --ci --reporters=jest-junit --reporters=default
   

   Note that --reporters=default is there b/c I wanted the default stdout in my build log.

3. Add a Publish Test Results task

   Since we’re using the default path, the test results file will be written to ~/junit.xml

4. (Optional) Add a publish code coverage task, too

   If you’re running code coverage, you might as well add a task for publishing the code coverage results, too:

If you’re using a YAML pipeline, here’s equivalent YAML (note that we’re using the yarn task instead of npm tasks, but that can be changed):

 - task: geeklearningio.gl-vsts-tasks-yarn.yarn-task.Yarn@2
    displayName: 'Install dependencies'
    inputs:
      Arguments: install --no-progress

  - task: geeklearningio.gl-vsts-tasks-yarn.yarn-task.Yarn@2
    displayName: 'Unit tests'
    inputs:
      Arguments: 'test --ci --reporters=jest-junit --reporters=default --coverage --coverageReporters=cobertura'
    continueOnError: true # Test failures should be published before failing the build

  - task: PublishTestResults@2
    displayName: 'Publish Jest Unit Test Results'
    inputs:
      testResultsFiles: junit.xml
      mergeTestResults: true
      testRunTitle: 'Jest Unit Tests'
      failTaskOnFailedTests: true

  - task: PublishCodeCoverageResults@1
    displayName: 'Publish code coverage from Jest tests'
    inputs:
      codeCoverageTool: Cobertura
      summaryFileLocation: '$(System.DefaultWorkingDirectory)/coverage/cobertura-coverage.xml'
      # reportDirectory: '$(System.DefaultWorkingDirectory)/coverage'
      failIfCoverageEmpty: true