feat: Add comprehensive Python testing infrastructure

[llbbl]

Add Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the morpholib project, providing all the necessary tools and configuration for developers to write and run tests effectively.

Changes Made

Package Management

• Poetry Setup: Created pyproject.toml with Poetry configuration as the package manager
• Dependencies:
  • Added numpy as a core dependency (required by morpholib)
  • Added testing dependencies: pytest, pytest-cov, pytest-mock as development dependencies

Testing Configuration

• pytest Configuration in pyproject.toml:

  • Test discovery patterns for flexible test file naming
  • Coverage reporting with HTML and XML output
  • 80% coverage threshold (configurable)
  • Strict markers and verbose output
  • Custom test markers: unit, integration, slow

• Coverage Configuration:

  • Source directory: morpholib
  • Excluded files: tests, dev tools, sample code
  • HTML report directory: htmlcov/
  • XML report: coverage.xml

Directory Structure

tests/
├── __init__.py
├── conftest.py              # Shared fixtures
├── test_setup_validation.py # Infrastructure validation
├── unit/
│   └── __init__.py
└── integration/
    └── __init__.py

Shared Fixtures (conftest.py)

• temp_dir: Temporary directory for test files
• sample_config: Sample configuration dictionary
• mock_cairo_context: Mocked Cairo graphics context
• mock_surface: Mocked Cairo surface
• sample_animation_data: Sample animation data structure
• sample_figure_data: Sample figure data structure
• cleanup_files: File cleanup tracker
• mock_ffmpeg: Mocked FFmpeg subprocess
• isolated_morpholib_import: Isolated import environment

Development Commands

Both commands work identically and run the full test suite:

• poetry run test
• poetry run tests

Updated .gitignore

Added entries for:

• Testing artifacts (.pytest_cache/, coverage.xml, htmlcov/)
• Claude settings (.claude/*)
• IDE files (.vscode/, .idea/, swap files)
• OS files (.DS_Store, Thumbs.db)

Running Tests

1. Install dependencies:

   poetry install
   

2. Run all tests:

   poetry run test
   # or
   poetry run tests
   

3. Run specific test categories:

   poetry run pytest -m unit        # Unit tests only
   poetry run pytest -m integration # Integration tests only
   poetry run pytest -m "not slow"  # Exclude slow tests
   

4. View coverage report:

   # After running tests, open htmlcov/index.html in a browser
   

Notes

• The coverage threshold is set to 80% but can be adjusted in pyproject.toml
• The validation test skips morpholib import if optional dependencies (pyglet, PIL) are missing
• Poetry lock file (poetry.lock) is tracked in version control for reproducible builds
• The infrastructure is ready for immediate test development - no actual unit tests for the codebase were written, only infrastructure validation tests