feat: Set up complete Python testing infrastructure with Poetry

[llbbl]

Set up Python Testing Infrastructure

Summary

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

Changes Made

Package Management

• Set up Poetry as the primary package manager with pyproject.toml
• Migrated dependencies from requirements.txt to Poetry configuration
• Added development dependencies: pytest, pytest-cov, pytest-mock

Testing Configuration

• Comprehensive pytest configuration in pyproject.toml including:
  • Test discovery patterns for different test types
  • Coverage settings with 80% threshold requirement
  • HTML and XML coverage report generation
  • Custom markers: unit, integration, slow for test categorization
  • Strict configuration to catch issues early

Directory Structure

• Created testing directories:
  • tests/ - Main testing directory
  • tests/unit/ - Unit tests
  • tests/integration/ - Integration tests
  • All directories include __init__.py files

Shared Test Utilities

• Comprehensive fixtures in tests/conftest.py:
  • temp_dir, temp_file - Temporary file system utilities
  • mock_config - Mock configuration objects
  • mock_pygame, mock_mido - Audio library mocks
  • mock_gtk, mock_gio - GTK/GIO component mocks
  • sample_sound_files, sample_preset_file - Test data generators
  • drum_pattern_data - Sample drum patterns
  • isolate_file_system - File system isolation
  • capturing_logger - Log capture for testing

Development Tools

• Poetry script commands:
  • poetry run test - Run all tests
  • poetry run tests - Alternative test command
• Updated .gitignore to exclude testing artifacts and include Claude Code settings

Validation

• Infrastructure validation tests in tests/test_infrastructure.py
• All fixtures and markers are tested and working
• Coverage reporting generates properly (HTML, XML, terminal)

How to Run Tests

# Install dependencies
poetry install

# Run all tests
poetry run pytest

# Run tests with verbose output
poetry run pytest -v

# Run specific test categories
poetry run pytest -m unit
poetry run pytest -m integration
poetry run pytest -m slow

# Run tests without coverage (for development)
poetry run pytest --no-cov

# Generate coverage reports
poetry run pytest --cov-report=html

Coverage Reports

• HTML coverage report: Generated in htmlcov/ directory
• XML coverage report: Generated as coverage.xml
• Terminal coverage: Shows missing lines in terminal output
• Coverage threshold: Set to 80% (configurable in pyproject.toml)

Testing Best Practices Enabled

• Isolated test environment with temporary directories
• Comprehensive mocking for external dependencies (GTK, pygame, mido)
• Fixture-based test data for consistent testing
• Multiple test categories with custom markers
• Coverage tracking with reasonable thresholds
• Strict pytest configuration to catch configuration issues

Notes

• The poetry.lock file is included in version control (not in .gitignore) for reproducible builds
• All testing dependencies are in the [tool.poetry.group.dev.dependencies] section
• The testing infrastructure is ready for immediate use - developers can start writing tests right away
• Validation tests confirm that all fixtures and configuration work correctly

🤖 Generated with Claude Code