cc-audit 3.2.14

name: Mutation Testing

on:
  schedule:
    # Run weekly on Sunday at 02:00 UTC
    - cron: '0 2 * * 0'
  workflow_dispatch:
  pull_request:
    branches: [main]
    paths:
      - 'src/**/*.rs'
      - 'Cargo.toml'
      - 'Cargo.lock'

env:
  CARGO_TERM_COLOR: always

jobs:
  mutation-test:
    name: Mutation Testing
    runs-on: ubuntu-latest
    # Only run on schedule or manual trigger for full mutation testing
    # For PRs, only run if explicitly requested via label
    if: github.event_name != 'pull_request' || contains(github.event.pull_request.labels.*.name, 'mutation-test')
    steps:
      - uses: actions/checkout@v6

      - uses: dtolnay/rust-toolchain@stable

      - uses: Swatinem/rust-cache@v2

      - name: Install cargo-mutants
        run: cargo install cargo-mutants --locked

      - name: Run mutation testing
        id: mutants
        run: |
          # Run with timeout and limited mutants for CI
          cargo mutants --timeout 60 --jobs 2 2>&1 | tee mutation-results.txt || true

      - name: Parse results
        run: |
          echo "## Mutation Testing Results" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY

          if [ -f mutants.out/caught.txt ]; then
            CAUGHT=$(wc -l < mutants.out/caught.txt | tr -d ' ')
          else
            CAUGHT=0
          fi

          if [ -f mutants.out/missed.txt ]; then
            MISSED=$(wc -l < mutants.out/missed.txt | tr -d ' ')
          else
            MISSED=0
          fi

          if [ -f mutants.out/timeout.txt ]; then
            TIMEOUT=$(wc -l < mutants.out/timeout.txt | tr -d ' ')
          else
            TIMEOUT=0
          fi

          TOTAL=$((CAUGHT + MISSED))
          if [ $TOTAL -gt 0 ]; then
            SCORE=$(echo "scale=1; $CAUGHT * 100 / $TOTAL" | bc)
          else
            SCORE="N/A"
          fi

          echo "| Metric | Count |" >> $GITHUB_STEP_SUMMARY
          echo "|--------|-------|" >> $GITHUB_STEP_SUMMARY
          echo "| Caught | $CAUGHT |" >> $GITHUB_STEP_SUMMARY
          echo "| Missed | $MISSED |" >> $GITHUB_STEP_SUMMARY
          echo "| Timeout | $TIMEOUT |" >> $GITHUB_STEP_SUMMARY
          echo "| **Score** | **${SCORE}%** |" >> $GITHUB_STEP_SUMMARY

          if [ "$MISSED" -gt 0 ]; then
            echo "" >> $GITHUB_STEP_SUMMARY
            echo "### Missed Mutants" >> $GITHUB_STEP_SUMMARY
            echo '```' >> $GITHUB_STEP_SUMMARY
            head -20 mutants.out/missed.txt >> $GITHUB_STEP_SUMMARY 2>/dev/null || echo "No missed mutants file"
            echo '```' >> $GITHUB_STEP_SUMMARY
          fi

      - name: Upload mutation results
        uses: actions/upload-artifact@v6
        if: always()
        with:
          name: mutation-results
          path: |
            mutants.out/
            mutation-results.txt
          retention-days: 30