name: Python Lint (tests/)

on:
  push:
    branches:
      - master
    paths:
      - 'tests/**/*.py'
      - 'tests/ruff.toml'
      - '.github/workflows/python-lint.yaml'
  pull_request:
    paths:
      - 'tests/**/*.py'
      - 'tests/ruff.toml'
      - '.github/workflows/python-lint.yaml'

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

jobs:
  ruff:
    name: Ruff (changed files only)
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Detect changed Python files under tests/
        id: changed
        uses: tj-actions/changed-files@v46
        with:
          files: tests/**/*.py

      - name: ruff check
        if: steps.changed.outputs.any_changed == 'true'
        uses: astral-sh/ruff-action@v4.0.0
        with:
          version: "0.15.11"
          src: ${{ steps.changed.outputs.all_changed_files }}

      - name: ruff format --check
        if: steps.changed.outputs.any_changed == 'true'
        uses: astral-sh/ruff-action@v4.0.0
        with:
          version: "0.15.11"
          src: ${{ steps.changed.outputs.all_changed_files }}
          args: "format --check --diff"

      - name: Validate ruff configuration (smoke test)
        # Always runs so config-only PRs still catch a broken ruff.toml.
        # --exit-zero ignores existing baseline violations; only fails when
        # ruff cannot load the config at all.
        uses: astral-sh/ruff-action@v4.0.0
        with:
          version: "0.15.11"
          src: "tests/scripts"
          args: "check --exit-zero"