name: tests

on:
  push:
    branches: [main]
  pull_request:

permissions:
  contents: read

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - name: Check out code
        uses: actions/checkout@v4
        with:
          persist-credentials: false
          fetch-depth: 0

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"

      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "22"

      - name: Install test dependencies
        run: python -m pip install --upgrade pillow

      - name: Run Python tests
        run: python -m unittest discover -s tests -p 'test_*.py' -v

      - name: Run frontend pure-function tests
        run: |
          node --test tests/test_gallery_math.mjs
          node --test tests/test_queue_groups.mjs
          node --test tests/test_reference_shelf.mjs

      - name: Check JavaScript syntax
        run: |
          node --check web/image_conveyor.js
          node --check web/image_conveyor_math.mjs

      - name: Check Python syntax
        run: python -m py_compile __init__.py image_conveyor.py image_conveyor_server.py

      - name: Check whitespace errors
        shell: bash
        env:
          EVENT_NAME: ${{ github.event_name }}
          BASE_REF: ${{ github.base_ref }}
          BEFORE_SHA: ${{ github.event.before }}
        run: |
          set -euo pipefail

          if [[ "$EVENT_NAME" == "pull_request" && -n "$BASE_REF" ]]; then
            git fetch --no-tags origin "$BASE_REF:refs/remotes/origin/$BASE_REF"
            compare_ref="origin/$BASE_REF"
          elif [[ "$EVENT_NAME" == "push" && -n "$BEFORE_SHA" && "$BEFORE_SHA" != "0000000000000000000000000000000000000000" ]]; then
            if ! git cat-file -e "$BEFORE_SHA^{commit}" 2>/dev/null; then
              git fetch --no-tags origin "$BEFORE_SHA"
            fi
            compare_ref="$BEFORE_SHA"
          elif git rev-parse --verify origin/main >/dev/null 2>&1; then
            compare_ref="origin/main"
          elif git rev-parse --verify HEAD^ >/dev/null 2>&1; then
            compare_ref="HEAD^"
          else
            compare_ref="HEAD"
          fi

          merge_base="$(git merge-base HEAD "$compare_ref")"
          git diff --check "$merge_base"...HEAD