homeracker

---
name: Mutation Tests

on:
  schedule:
    - cron: '0 3 * * 1'  # Weekly: Monday 03:00 UTC
  workflow_dispatch:
  workflow_call:

permissions: {}

env:
  # Lets tests catch text I/O without an explicit encoding (see [tool.pytest.ini_options] in cmd/scadm/pyproject.toml and cmd/scadfmt/pyproject.toml).
  PYTHONWARNDEFAULTENCODING: '1'
  # Silences the same warning from mutmut and other tooling. pytest's own filter still turns it into an error inside tests.
  PYTHONWARNINGS: 'ignore::EncodingWarning'

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

jobs:
  # Mutates only the functions a PR changed, one comment section per package. A change to a package's run setup gets a full run of it.
  # Release PRs only bump versions and changelogs; their code was mutation-tested on its own PRs.
  pr:
    if: github.event_name == 'pull_request' && !startsWith(github.head_ref, 'release-please--')
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          persist-credentials: false
          fetch-depth: 0

      - name: Set up Python
        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
        with:
          python-version: '3.14'

      - name: Install dependencies
        run: |
          set -euo pipefail
          pip install -e cmd/scadm -e cmd/scadfmt pytest -r requirements.txt

      # Per package: pick the scope, run mutmut capped at 5 minutes so a growing suite can't stall PRs
      # (results collected before the cap are kept), then render its section of the PR comment.
      - name: Run mutation tests
        env:
          BASE_SHA: ${{ github.event.pull_request.base.sha }}
        run: |
          set -euo pipefail
          sections=()
          for package in scadm scadfmt; do
            globs="$RUNNER_TEMP/$package-globs.txt"
            python cmd/test/mutation_report.py scope --package "$package" --base "$BASE_SHA" > "$globs"
            setup_changed=$(git diff --name-only "$BASE_SHA...HEAD" -- \
              "cmd/$package/pyproject.toml" cmd/test/mutation_report.py requirements.txt .github/workflows/mutation-tests.yml)
            args=()
            names=()
            if [[ -z "$setup_changed" ]]; then
              args+=(--globs-file "$globs")
              # grep exits 1 on an empty scope; any other failure stops the job.
              scoped=$(grep . "$globs" || [[ $? -eq 1 ]])
              if [[ -n "$scoped" ]]; then
                mapfile -t names <<< "$scoped"
              fi
            fi
            if [[ -n "$setup_changed" || ${#names[@]} -gt 0 ]]; then
              rc=0
              (cd "cmd/$package" && timeout --kill-after=30s 300 mutmut run "${names[@]}") || rc=$?
              if [[ "$rc" -eq 124 || "$rc" -eq 137 ]]; then
                echo "::warning title=Mutation run timed out ($package)::Results are partial. If this keeps happening, move per-PR mutation runs to a nightly job."
                args+=(--timed-out)
              elif [[ "$rc" -ne 0 ]]; then
                exit "$rc"
              fi
            fi
            python cmd/test/mutation_report.py report --package "$package" "${args[@]}" > "$RUNNER_TEMP/$package.md"
            sections+=("$RUNNER_TEMP/$package.md")
          done
          python cmd/test/mutation_report.py combine "${sections[@]}" > "$RUNNER_TEMP/report.md"
          cat "$RUNNER_TEMP/report.md" >> "$GITHUB_STEP_SUMMARY"

      # Fork PRs get a read-only token, so they rely on the job summary above.
      - name: Upsert PR comment
        if: github.event.pull_request.head.repo.full_name == github.repository
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
          PR: ${{ github.event.pull_request.number }}
        run: |
          set -euo pipefail
          ids=$(gh api "repos/$REPO/issues/$PR/comments" --paginate \
            --jq '.[] | select(.body | startswith("<!-- mutation-report -->")) | .id')
          existing=${ids%%$'\n'*}
          if [[ -z "$existing" ]]; then
            gh api -X POST "repos/$REPO/issues/$PR/comments" -F body=@"$RUNNER_TEMP/report.md" --silent
          else
            gh api -X PATCH "repos/$REPO/issues/comments/$existing" -F body=@"$RUNNER_TEMP/report.md" --silent
          fi

  # Whole package, to keep overall test debt visible: report to Discord, refresh the package's mutation badge.
  full:
    if: github.event_name != 'pull_request'
    runs-on: ubuntu-latest
    timeout-minutes: 60
    permissions:
      contents: write
    strategy:
      fail-fast: false
      matrix:
        include:
          - package: scadm
            badge: mutation.json
          - package: scadfmt
            badge: scadfmt-mutation.json
    env:
      PACKAGE: ${{ matrix.package }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          persist-credentials: true # publish-badge pushes with these

      - name: Set up Python
        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
        with:
          python-version: '3.14'

      - name: Install dependencies
        run: |
          set -euo pipefail
          pip install -e "cmd/$PACKAGE" pytest -r requirements.txt

      - name: Run mutation tests
        working-directory: cmd/${{ matrix.package }}
        run: |
          set -euo pipefail
          mutmut run
          mutmut export-cicd-stats
          mutmut badge --output "$RUNNER_TEMP/mutation.json"

      - name: Build report
        run: |
          set -euo pipefail
          python cmd/test/mutation_report.py report --package "$PACKAGE" >> "$GITHUB_STEP_SUMMARY"

      - name: Post to Discord
        env:
          DISCORD_CI_WEBHOOK_URL: ${{ secrets.DISCORD_CI_WEBHOOK_URL }}
          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
        run: |
          set -euo pipefail
          if [[ -z "$DISCORD_CI_WEBHOOK_URL" ]]; then
            echo "::warning::DISCORD_CI_WEBHOOK_URL is not set, skipping the Discord report"
            exit 0
          fi
          python cmd/test/mutation_report.py discord --package "$PACKAGE" --run-url "$RUN_URL" > "$RUNNER_TEMP/discord.json"
          curl -fsS -H "Content-Type: application/json" -d @"$RUNNER_TEMP/discord.json" "$DISCORD_CI_WEBHOOK_URL"

      - name: Publish mutation badge
        if: github.ref == 'refs/heads/main'
        uses: ./.github/actions/publish-badge
        with:
          file: ${{ runner.temp }}/mutation.json
          name: ${{ matrix.badge }}