ci.yml

name: CI

on:
  push:
    branches: [main, master]
  pull_request:
    branches: [main, master]

jobs:
  test:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    # 2026-07-08: fail-fast on the first matrix failure instead of
    # wasting runner minutes on the remaining Python versions when
    # the suite is already red. Speed gain is per-run, not per-test.
    strategy:
      fail-fast: true
      matrix:
        python: ["3.10", "3.11", "3.12"]

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python ${{ matrix.python }}
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python }}
          # Cache pip's download cache keyed on the lock-relevant
          # surfaces of pyproject.toml. Skips the ~60-90s cold
          # install on warm caches; the action also reuses the
          # cache across matrix legs when the key matches.
          cache: "pip"
          cache-dependency-path: pyproject.toml

      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          # xdist ships in the dev tree already; pin it explicitly so
          # a future deps churn can't drop it without breaking CI.
          # ``pytest-rerunfailures`` is used by Sprint 0 (coverage) on
          # a single rare-flaky test under pytest-xdist on linux
          # (thread-scheduling race in the approval-wait fixture);
          # pin it for the same reason.
          pip install -e ".[dev]" "pytest-xdist>=3.6" "pytest-rerunfailures>=14.0,<16.0"

      - name: Run tests
        # `-n auto` lets xdist pick a worker count from the runner's
        # CPU count. With the transport cancellable-sleep fix the
        # 5s-per-shutdown multiplier is gone, and xdist plus the
        # existing respx-based mocking keeps the per-test wall clock
        # near single-thread baseline (no shared state between
        # workers — ``reset_runtime`` autouse fixture in conftest
        # is per-process by construction under xdist).
        run: pytest -n auto --durations=20

      - name: Run ruff
        run: ruff check src/

      - name: Run mypy
        run: mypy src/

  coverage:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"
          cache-dependency-path: pyproject.toml
      - run: pip install -e ".[dev]" "pytest-xdist>=3.6" "pytest-cov>=5.0"
      # Single Python leg for coverage — multi-version coverage
      # reports don't add signal and double the runner time. 3.12
      # is the modern floor for typing-only changes.
      # pytest-cov starts coverage in every xdist worker and combines
      # the data before producing the report. ``coverage run`` only
      # traced the coordinator process, so every parallel run uploaded
      # 0 hits even though all tests passed.
      - run: pytest -n auto --cov=src/nullrun --cov-branch --cov-report=xml:coverage.xml --cov-report=term
      - uses: codecov/codecov-action@v4
        if: always()
        with:
          token: ${{ secrets.CODECOV_TOKEN }}
          files: ./coverage.xml
          fail_ci_if_error: true