name: Backend Tests

# Runs on backend and extension changes. Tests are co-located with the
# code (src/backend/**/*.test.ts, extensions/**/*.test.ts), so test-only
# changes match the same globs. puter.js SDK changes are covered by
# puterjs-tests.yaml instead.
on:
  pull_request:
    types: [opened, synchronize, reopened]
    paths:
      - 'src/backend/**'
      - 'extensions/**'
      - 'tools/**'
      - 'package.json'
      - 'package-lock.json'
      # The type-check job below reads these.
      - 'tsconfig.json'
      - 'tsconfig.build.json'
      - '.github/workflows/backend-tests.yaml'

permissions:
  contents: read
  pull-requests: write

jobs:
  # `tsconfig.build.json` builds with `noCheck: true`, so nothing else in CI
  # runs the type checker and a missing export compiles to `undefined`,
  # surfacing only when the call is finally reached at runtime. This diffs
  # against tools/typecheck-baseline.json and fails only on *new* errors.
  #
  # The consuming repo runs an equivalent gate, but only once someone bumps the
  # submodule pointer — too late to keep the error off this repo's default
  # branch. Hence a gate here, on this repo's own pull requests.
  #
  # Its own job rather than a step in `test`: that one runs a base/PR matrix for
  # coverage comparison, and the check only needs the PR ref, once.
  typecheck:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '24'
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Type check (new errors only)
        run: npm run typecheck

  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - ref: ${{ github.base_ref }}
            artifact: base
          - ref: ${{ github.head_ref }}
            artifact: pr

    steps:
      - name: Checkout ${{ matrix.ref }}
        uses: actions/checkout@v4
        with:
          ref: ${{ matrix.ref }}
          repository: ${{ github.event.pull_request.head.repo.full_name }}

      - name: Set up Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '24'
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Run backend tests with coverage
        run: npm run test:backend -- --coverage
        env:
          CI: 'true'

      - name: Upload coverage artifact
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: backend-coverage-${{ matrix.artifact }}
          path: src/backend/coverage/
          retention-days: 14

  report-coverage:
    needs: test
    if: always()
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Download PR coverage
        uses: actions/download-artifact@v4
        with:
          name: backend-coverage-pr
          path: src/backend/coverage

      - name: Download base coverage
        uses: actions/download-artifact@v4
        with:
          name: backend-coverage-base
          path: coverage-base

      - name: Report coverage on PR
        uses: davelosert/vitest-coverage-report-action@v2
        with:
          json-summary-path: src/backend/coverage/coverage-summary.json
          json-final-path: src/backend/coverage/coverage-final.json
          json-summary-compare-path: coverage-base/coverage-summary.json