mutation-testing.yml

name: Changed-code mutation testing

on:
    pull_request:
        types: [edited, opened, reopened, ready_for_review, synchronize]
    merge_group:
        types: [checks_requested]

permissions:
    contents: read

concurrency:
    group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
    cancel-in-progress: true

jobs:
    mutation-diff:
        name: mutation-diff
        if: github.event_name == 'merge_group' || github.event.pull_request.draft == false
        runs-on: ubuntu-latest
        timeout-minutes: 30
        steps:
            - name: Record merge-queue enforcement
              if: github.event_name == 'merge_group'
              run: |
                  {
                      echo "## Changed-code mutation testing"
                      echo "Mutation testing was enforced on each pull request before it entered the merge queue."
                  } >> "$GITHUB_STEP_SUMMARY" || echo "::warning title=Mutation test advisory::Could not write the job summary"

            - name: Checkout pull request merge result
              if: github.event_name == 'pull_request'
              uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
              with:
                  ref: ${{ github.sha }}
                  fetch-depth: 0
                  persist-credentials: false

            - name: Setup Node.js and pnpm
              if: github.event_name == 'pull_request'
              uses: ./.github/actions/setup-node-pnpm
              with:
                  install-args: "--frozen-lockfile"

            - name: Test mutation gate logic
              if: github.event_name == 'pull_request'
              run: pnpm test:mutation-ci

            - name: Enforce executable-line scope and run advisory mutation testing
              if: github.event_name == 'pull_request'
              env:
                  HEAD_SHA: ${{ github.sha }}
                  PR_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
              run: |
                  BASE_SHA="$(git rev-parse "$HEAD_SHA^1")"
                  node scripts/stryker-diff.mjs ci --base "$BASE_SHA" --head "$HEAD_SHA"

            - name: Upload mutation reports
              id: mutation_report
              if: always() && github.event_name == 'pull_request'
              continue-on-error: true
              uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
              with:
                  name: changed-code-mutation-report
                  path: reports/mutation/
                  if-no-files-found: ignore
                  retention-days: 7

            - name: Link mutation report artifact
              if: always() && github.event_name == 'pull_request' && steps.mutation_report.outputs.artifact-url != ''
              env:
                  ARTIFACT_URL: ${{ steps.mutation_report.outputs.artifact-url }}
              run: |
                  {
                      echo ""
                      echo "### Download mutation reports"
                      echo "[Open the changed-code-mutation-report artifact]($ARTIFACT_URL), then open the package's mutation.html file."
                  } >> "$GITHUB_STEP_SUMMARY" || echo "::warning title=Mutation test advisory::Could not write the job summary"