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 Python project using Poetry as the package manager and pytest as the testing framework. The setup provides a solid foundation for writing and running tests with proper coverage reporting and organization.

Changes Made

Package Management

• Poetry Configuration: Set up Poetry as the package manager with a complete pyproject.toml configuration
• No Migration Needed: No existing dependencies found in requirements.txt or setup.py

Testing Framework

• Dependencies Added:
  • pytest (^7.4.0) - Core testing framework
  • pytest-cov (^4.1.0) - Coverage reporting plugin
  • pytest-mock (^3.11.0) - Mocking utilities

Configuration

• pytest Settings:

  • Test discovery patterns for test_*.py and *_test.py files
  • Coverage reporting in HTML, XML, and terminal formats
  • Custom markers: unit, integration, and slow
  • Strict marker enforcement
  • Verbose output by default

• Coverage Settings:

  • Source directory: code/
  • Excluded: tests, cache, virtual environments, migrations
  • 80% coverage threshold (informational only)
  • HTML reports in htmlcov/ directory
  • XML reports as coverage.xml

Project Structure

tests/
├── __init__.py
├── conftest.py          # Shared fixtures and configuration
├── unit/                # Unit tests directory
│   └── __init__.py
├── integration/         # Integration tests directory
│   └── __init__.py
└── test_setup_validation.py  # Validation tests

Fixtures (conftest.py)

• temp_dir: Temporary directory with automatic cleanup
• mock_config: Mock configuration object
• sample_data: Sample data for testing
• mock_model: Mock ML model with predict/train/evaluate methods
• test_image_path: Creates temporary test image files
• json_file: Helper for creating temporary JSON files
• capture_logs: Log message capture utility
• reset_environment: Auto-reset environment variables
• mock_file_operations: Mock file system operations

.gitignore Updates

• Python artifacts: __pycache__/, *.pyc, virtual environments
• Testing artifacts: .pytest_cache/, .coverage, htmlcov/, coverage.xml
• Claude artifacts: .claude/*
• IDE and OS files

Running Tests

Basic Commands

# Install dependencies
poetry install

# Run all tests
poetry run test
# or
poetry run tests

# Run with specific markers
poetry run pytest -m unit
poetry run pytest -m integration
poetry run pytest -m "not slow"

# Run specific test file
poetry run pytest tests/test_setup_validation.py

# Run with coverage only
poetry run pytest --cov=code --cov-report=html

Validation Results

All 10 validation tests pass successfully:

• ✅ pytest installation verified
• ✅ Project structure validated
• ✅ pyproject.toml configuration checked
• ✅ Custom markers functional
• ✅ Fixtures available and working
• ✅ Coverage tools configured
• ✅ Mock utilities available
• ✅ Code package importable
• ✅ Integration test setup verified
• ✅ Slow marker functional

Notes

• The coverage warning about "no data collected" is expected since we haven't written actual tests for the codebase yet
• Both poetry run test and poetry run tests commands are configured and working
• The poetry.lock file is NOT gitignored as per best practices
• The 80% coverage threshold is set in the configuration but won't fail builds (removed --cov-fail-under from pytest args)

Next Steps

Developers can now immediately start writing tests by:

1. Creating test files in tests/unit/ or tests/integration/
2. Using the provided fixtures from conftest.py
3. Running tests with poetry run test
4. Viewing coverage reports in htmlcov/index.html