mutation-testing.yml

name: Mutation Testing

on:
  pull_request:
    paths:
      - "src/**"
      - "tests/**"
      - "composer.json"
      - "phpunit.xml"
      - ".github/workflows/mutation-testing.yml"
  schedule:
    - cron: "41 3 * * 0"
  workflow_dispatch:

permissions:
  contents: read

jobs:
  mutation:
    runs-on: ubuntu-latest
    timeout-minutes: 90
    name: Pest mutation tests

    steps:
      - name: Checkout code
        uses: actions/checkout@v7
        with:
          fetch-depth: 0

      - name: Setup PHP
        uses: shivammathur/setup-php@v2
        with:
          php-version: "8.4"
          extensions: dom, libxml, mbstring, simplexml, tokenizer, xmlwriter, zip
          coverage: pcov

      - name: Install project dependencies
        run: composer update --prefer-stable --prefer-dist --no-interaction

      - name: Run mutation tests
        env:
          EVENT_NAME: ${{ github.event_name }}
          BASE_REF: ${{ github.base_ref }}
        run: |
          if [ "$EVENT_NAME" = "pull_request" ]; then
            git fetch origin "$BASE_REF"
            MUTATION_PATHS="$(git diff --name-only --diff-filter=AMR "origin/$BASE_REF...HEAD" -- 'src/*.php' 'src/**/*.php' | paste -sd, -)"

            if [ -z "$MUTATION_PATHS" ]; then
              echo "No changed PHP source files to mutate."
              exit 0
            fi

            vendor/bin/pest \
              --mutate \
              --parallel \
              --path="$MUTATION_PATHS" \
              --covered-only \
              --ignore-min-score-on-zero-mutations \
              --min=50
          else
            vendor/bin/pest \
              --mutate \
              --parallel \
              --everything \
              --covered-only \
              --min=50
          fi