init_pytest.py

#!/usr/bin/env python3
"""
Initialize a robust pytest setup in the current directory (or --path).

Creates:
- tests/test_sample.py
- tests/conftest.py
- pytest.ini
- .coveragerc
- requirements-dev.txt
- .github/workflows/python-tests.yml (with --ci)

Usage:
  python3 skill-pytest/init_pytest.py [--path .] [--package yourpkg] [--ci] [--overwrite]

Run dev deps:
  python3 -m pip install -r requirements-dev.txt
  pytest -q --cov
"""

from __future__ import annotations

import argparse
import os
from pathlib import Path
import textwrap


def write_file(path: Path, content: str, overwrite: bool = False) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    if path.exists() and not overwrite:
        return
    path.write_text(content, encoding="utf-8")


def main() -> int:
    p = argparse.ArgumentParser(description="Scaffold pytest configuration and CI")
    p.add_argument("--path", default=".", help="Target project directory")
    p.add_argument("--package", default="", help="Package/module name for coverage source (optional)")
    p.add_argument("--ci", action="store_true", help="Add GitHub Actions workflow")
    p.add_argument("--overwrite", action="store_true", help="Overwrite existing files if present")
    args = p.parse_args()

    root = Path(args.path).resolve()
    overwrite = args.overwrite

    pkg = args.package.strip()
    cov_source = pkg if pkg else ""

    # tests/test_sample.py
    test_sample = textwrap.dedent(
        """
        def test_sample_sum():
            assert sum([1, 2, 3]) == 6
        """
    ).lstrip()
    write_file(root / "tests" / "test_sample.py", test_sample, overwrite)

    # tests/conftest.py
    conftest = textwrap.dedent(
        """
        import os
        import random
        import pytest

        @pytest.fixture(autouse=True)
        def _seed_random():
            random.seed(1337)
            os.environ.setdefault("PYTHONHASHSEED", "0")

        @pytest.fixture
        def tmp_cwd(tmp_path, monkeypatch):
            monkeypatch.chdir(tmp_path)
            return tmp_path
        """
    ).lstrip()
    write_file(root / "tests" / "conftest.py", conftest, overwrite)

    # pytest.ini
    pytest_ini = textwrap.dedent(
        """
        [pytest]
        minversion = 7.0
        addopts = -ra
        testpaths = tests
        xfail_strict = true
        filterwarnings =
            error::DeprecationWarning
        markers =
            unit: fast unit tests
            integration: tests using external services or IO
            slow: long-running tests
            flaky: non-deterministic tests (aim to eliminate)
        """
    ).lstrip()
    write_file(root / "pytest.ini", pytest_ini, overwrite)

    # .coveragerc
    coveragerc = textwrap.dedent(
        f"""
        [run]
        branch = True
        {('source =\n    ' + cov_source) if cov_source else '# Set --package to track a package as coverage source'}

        [report]
        show_missing = True
        skip_covered = True
        fail_under = 80
        """
    ).lstrip()
    write_file(root / ".coveragerc", coveragerc, overwrite)

    # requirements-dev.txt
    reqs = textwrap.dedent(
        """
        pytest>=7.0
        pytest-cov>=4.0
        pytest-asyncio>=0.23
        pytest-mock>=3.12
        """
    ).lstrip()
    write_file(root / "requirements-dev.txt", reqs, overwrite)

    # GitHub Actions workflow (optional)
    if args.ci:
        workflow = textwrap.dedent(
            f"""
            name: Python tests

            on: [push, pull_request]

            jobs:
              test:
                runs-on: ubuntu-latest
                strategy:
                  matrix:
                    python-version: ["3.10", "3.11", "3.12"]
                steps:
                  - uses: actions/checkout@v4
                  - uses: actions/setup-python@v5
                    with:
                      python-version: ${{ matrix.python-version }}
                  - name: Install deps
                    run: |
                      python -m pip install --upgrade pip
                      if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
                      if [ -f pyproject.toml ]; then pip install -e .; fi
                  - name: Run tests
                    run: |
                      pytest -q {'--cov=' + cov_source if cov_source else ''} --cov-report=term-missing
            """
        ).lstrip()
        write_file(root / ".github" / "workflows" / "python-tests.yml", workflow, overwrite)

    created = [
        root / "tests" / "test_sample.py",
        root / "tests" / "conftest.py",
        root / "pytest.ini",
        root / ".coveragerc",
        root / "requirements-dev.txt",
    ]
    if args.ci:
        created.append(root / ".github" / "workflows" / "python-tests.yml")

    print("Created/verified files:")
    for p in created:
        rel = os.path.relpath(p, start=os.getcwd())
        print(" -", rel)

    print("\nNext:")
    print("  python3 -m pip install -r requirements-dev.txt")
    print("  pytest -q --cov")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())