report-incremental-coverage.yaml

name: Report Incremental Coverage

# Runs when the build and test workflow completes.  This will run with full
# privileges, even if the other workflow doesn't.  That allows us to leave PR
# comments, when we would not be able to do so otherwise.
on:
  workflow_run:
    workflows: [Build and Test]
    types: [completed]

jobs:
  report:
    if: ${{ github.event.workflow_run.event == 'pull_request' }}
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          persist-credentials: false

      - name: Compute incremental code coverage
        id: compute
        shell: bash
        env:
          GITHUB_TOKEN: ${{ secrets.SHAKA_BOT_TOKEN }}
        # Fetches the coverage data from the run that triggered the report,
        # parses it, compares it to the changed lines in the PR, and computes
        # the incremental code coverage.
        run: |
          python .github/workflows/compute-incremental-coverage.py \
              --repo ${{ github.repository }} \
              --run-id ${{ github.event.workflow_run.id }}

      - name: Report incremental code coverage
        shell: bash
        env:
          GITHUB_TOKEN: ${{ secrets.SHAKA_BOT_TOKEN }}
          PR_NUMBER: ${{ steps.compute.outputs.pr_number }}
          MESSAGE: "Incremental code coverage: ${{ steps.compute.outputs.coverage }}"
          COMMENT_INCLUDES: "Incremental code coverage: "
          COMMENT_USER: "shaka-bot"
        run: |
          # Look for an old comment
          jq_filter=".[] | select((.user.login == \"$COMMENT_USER\") and (.body | startswith(\"$COMMENT_INCLUDES\"))) | .id"
          gh api \
            /repos/${{ github.repository }}/issues/$PR_NUMBER/comments \
            | jq "$jq_filter" > old-comment-id

          if [[ -z "$(cat old-comment-id)" ]]; then
            # Create a new comment
            gh api \
              --method POST \
              /repos/${{ github.repository }}/issues/$PR_NUMBER/comments \
              -F "body=$MESSAGE"
          else
            # Update an old comment
            gh api \
              --method PATCH \
              /repos/${{ github.repository }}/issues/comments/$(cat old-comment-id) \
              -F "body=$MESSAGE"
          fi