Support of specifying a commit to post the status

[HyukjinKwon]

This PR proposes to add an argument commit to specify the target commit to upload the test reports.

For a bit of background and context:

Seems currently this plugin cannot be widely used in case of open source projects where the pull requests come from forked repositories. This is a known issue in GitHub Actions because other secrets are not passed and GITHUB_TOKEN secret only has read access. Creating the status requires a write access.

I discussed with GitHub team, and managed to make this plugin working via leveraging workflow_run, which. is new feature (10 days ago). However, I had to fork this repository to make it working with the current fix.

Please see apache/spark#29333 for more details, and https://github.com/HyukjinKwon/spark/runs/979894025 as a demo.

TL;DR:

Adding this argument can make this plugin works in most of open source projects where the PRs are from forked repository via having two separate workflows as below:

name: Build and test

on:
  pull_request:
    branches:
    - master

jobs:
  test:
    runs-on: ubuntu-latest
    - name: Run tests
      # Run tests ...
    - name: Upload test results to report
      if: always()
      uses: actions/upload-artifact@v2
      with:
        name: test-results.xml
        path: "*.xml"

name: Report test results
on:
  workflow_run:
    workflows: ["Build and test"]
    types:
      - completed

jobs:
  test_report:
    runs-on: ubuntu-latest
    steps:
    - name: Download test results to report
      # Download the artifact. See also https://developer.github.com/v3/actions/workflow-runs/
      # and see https://developer.github.com/v3/actions/artifacts/
      # ... workflow: ${{ github.event.workflow_run.workflow_id }} ...
    - name: Publish test report
      with:
        github_token: ${{ secrets.GITHUB_TOKEN }}
        report_paths: "*.xml"
        # Update the test status in the commit that triggered the previous workflow.
        commit: ${{ github.event.workflow_run.head_commit.id }}

[HyukjinKwon]

The test in this PR itself fails with Resource not accessible by integration because my PR is from the forked repository as described above.

I manually verified that the tests pass in my own forked directory: HyukjinKwon@c96094c. I also manually tested this new feature at apache/spark#29333 and https://github.com/HyukjinKwon/spark/runs/981169622.

[jmisur]

Hey @HyukjinKwon, thanks for the PR and comprehensive description. Great job.

[HyukjinKwon]

Thank you so much!