feat: Set up comprehensive Python testing infrastructure with Poetry

[llbbl]

Set Up Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the IPython Cookbook project using Poetry as the package manager and pytest as the testing framework.

Changes Made

Package Management

• Poetry Configuration: Created pyproject.toml with Poetry configuration
  • Set up project metadata
  • Configured package-mode as false (dependency management only)
  • Added test/dev dependencies: pytest, pytest-cov, pytest-mock

Testing Configuration

• pytest Configuration in pyproject.toml:

  • Test discovery patterns for test_*.py and *_test.py files
  • Coverage settings with 80% threshold
  • HTML and XML coverage report generation
  • Custom markers: unit, integration, slow
  • Strict marker enforcement

• Coverage Configuration:

  • Source includes all project files
  • Excludes test files, virtual environments, and build artifacts
  • Precision set to 2 decimal places
  • Shows missing lines in coverage reports

Directory Structure

tests/
├── __init__.py
├── conftest.py           # Shared fixtures and configuration
├── test_infrastructure.py # Validation tests
├── unit/
│   └── __init__.py
└── integration/
    └── __init__.py

Shared Fixtures (conftest.py)

• temp_dir: Creates temporary directories for testing
• temp_file: Creates temporary files with content
• mock_config: Provides mock configuration dictionaries
• sample_data: Sample data structures for testing
• mock_notebook_data: Mock Jupyter notebook structures
• reset_environment: Auto-resets environment variables
• capture_logs: Log capture configuration
• mock_http_response: Factory for creating mock HTTP responses

Development Commands

Both commands are available for running tests:

• poetry run pytest - Direct pytest execution
• Standard pytest options are available (e.g., -v, -k, --runslow)

.gitignore Updates

Added comprehensive entries for:

• Testing artifacts (.pytest_cache/, .coverage, htmlcov/)
• Python artifacts (__pycache__/, *.pyc, *.pyo)
• Virtual environments
• Build artifacts
• IDE files
• Claude settings (.claude/*)

How to Use

1. Install dependencies:

   poetry install

2. Run all tests:

   poetry run pytest

3. Run tests with coverage:

   poetry run pytest --cov

4. Run specific test markers:

   poetry run pytest -m unit        # Run only unit tests
   poetry run pytest -m integration # Run only integration tests
   poetry run pytest --runslow      # Include slow tests

5. View coverage report:

   • HTML report: Open htmlcov/index.html in a browser
   • Terminal report: Included by default when running tests

Notes

• The infrastructure is ready for immediate use - developers can start writing tests in the tests/unit/ or tests/integration/ directories
• Coverage threshold is set to 80% but will only apply once actual code is added to the project
• All validation tests pass, confirming the infrastructure is properly configured
• Poetry lock file is tracked in git for reproducible builds