mutants.yml

name: Mutation Testing

on:
  schedule:
    - cron: "0 3 * * 1" # Monday 3am UTC
  workflow_dispatch:
    inputs:
      packages:
        description: "Comma-separated crate names (empty = all off-chain)"
        required: false
        type: string
      extra_args:
        description: "Extra cargo-mutants args (e.g. --shard 1/4)"
        required: false
        type: string

concurrency:
  group: mutants-${{ github.ref }}
  cancel-in-progress: true

jobs:
  mutants:
    name: cargo-mutants
    runs-on: ubuntu-latest
    timeout-minutes: 90
    defaults:
      run:
        working-directory: backend

    steps:
      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1

      - uses: Swatinem/rust-cache@23869a5bd66c73db3c0ac40331f3206eb23791dc # v2.9.1
        with:
          workspaces: backend -> target

      - name: Install cargo-mutants
        run: cargo install cargo-mutants@27.0.0 --locked

      - name: Run mutation tests
        env:
          INPUT_PACKAGES: ${{ inputs.packages }}
          INPUT_EXTRA_ARGS: ${{ inputs.extra_args }}
        run: |
          ARGS="--in-place"

          if [ -n "$INPUT_PACKAGES" ]; then
            IFS=',' read -ra PKGS <<< "$INPUT_PACKAGES"
            for pkg in "${PKGS[@]}"; do
              ARGS="$ARGS --package $(echo "$pkg" | xargs)"
            done
          else
            for pkg in api-gateway indexer issuer-service sanctions-updater zksettle-crypto zksettle-types; do
              ARGS="$ARGS --package $pkg"
            done
          fi

          if [ -n "$INPUT_EXTRA_ARGS" ]; then
            ARGS="$ARGS $INPUT_EXTRA_ARGS"
          fi

          cargo mutants $ARGS

      - name: Generate summary
        if: always()
        run: |
          OUTCOMES="mutants.out/outcomes.json"
          if [ ! -f "$OUTCOMES" ]; then
            echo "No outcomes.json found" >> "$GITHUB_STEP_SUMMARY"
            exit 0
          fi

          CAUGHT=$(jq '[.outcomes[] | select(.scenario != "Baseline" and .summary == "CaughtMutant")] | length' "$OUTCOMES")
          MISSED=$(jq '[.outcomes[] | select(.scenario != "Baseline" and .summary == "MissedMutant")] | length' "$OUTCOMES")
          TIMEOUT=$(jq '[.outcomes[] | select(.scenario != "Baseline" and .summary == "Timeout")] | length' "$OUTCOMES")
          UNVIABLE=$(jq '[.outcomes[] | select(.scenario != "Baseline" and .summary == "Unviable")] | length' "$OUTCOMES")
          TESTED=$((CAUGHT + MISSED + TIMEOUT))

          if [ "$TESTED" -gt 0 ]; then
            SCORE=$(( (CAUGHT * 100) / TESTED ))
          else
            SCORE=0
          fi

          cat >> "$GITHUB_STEP_SUMMARY" <<EOF
          ## Mutation Testing Results

          | Metric | Count |
          |--------|-------|
          | Caught | $CAUGHT |
          | Missed | $MISSED |
          | Timeout | $TIMEOUT |
          | Unviable | $UNVIABLE |
          | **Score** | **${SCORE}%** |

          EOF

          if [ "$MISSED" -gt 0 ]; then
            echo "### Surviving Mutants" >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
            jq -r '.outcomes[] | select(.summary == "MissedMutant") | "\(.scenario.Mutant.function) in \(.scenario.Mutant.source_file)"' "$OUTCOMES" >> "$GITHUB_STEP_SUMMARY"
            echo '```' >> "$GITHUB_STEP_SUMMARY"
          fi

      - name: Upload mutation report
        if: always()
        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
        with:
          name: mutation-report
          path: backend/mutants.out/
          retention-days: 30