feat: Set up comprehensive Python testing infrastructure

[llbbl]

Set Up Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the Python project, providing a ready-to-use environment for writing and running tests with proper coverage tracking and reporting.

Changes Made

Package Manager Setup

• ✅ Configured Poetry as the package manager
• ✅ Created pyproject.toml with complete project configuration
• ✅ Set package-mode = false since this is primarily for dependency management

Testing Dependencies

Added the following development dependencies:

• pytest (^8.0.0) - Main testing framework
• pytest-cov (^4.1.0) - Coverage reporting integration
• pytest-mock (^3.12.0) - Enhanced mocking capabilities

Testing Configuration

Configured comprehensive testing settings in pyproject.toml:

• Test discovery: Configured patterns for test files, classes, and functions
• Pytest options: Strict markers, verbose output, short tracebacks
• Custom markers: unit, integration, and slow for test categorization
• Coverage settings:
  • Source directories specified
  • Comprehensive exclusion patterns
  • Multiple report formats (HTML, XML, terminal)
  • 80% coverage threshold target

Directory Structure

Created proper testing hierarchy:

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

Test Fixtures

Added comprehensive fixtures in conftest.py:

• temp_dir - Temporary directory management
• mock_config - Configuration object mocking
• mock_logger - Logger mocking
• sample_data - Test data generation
• mock_api_response - API response mocking
• mock_file_system - File system structure mocking
• reset_environment - Environment variable cleanup
• mock_database - Database connection mocking
• capture_logs - Log message capture
• benchmark_timer - Simple performance timing

Additional Configuration

• Updated .gitignore with:
  • Testing artifacts (.pytest_cache/, coverage.xml, htmlcov/)
  • Claude settings (.claude/*)
  • IDE files and temporary files
  • Note: poetry.lock is intentionally NOT ignored

Validation

• Created test_validation.py with 11 tests to verify:
  • Testing infrastructure is properly configured
  • All fixtures are working correctly
  • Markers are properly registered
  • Coverage tools are integrated

How to Use

Running Tests

Basic test execution:

poetry run pytest

With coverage reporting:

poetry run pytest --cov=python-examples --cov-report=html --cov-report=xml --cov-report=term-missing

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

Writing Tests

1. Unit tests: Place in tests/unit/ directory
2. Integration tests: Place in tests/integration/ directory
3. Use fixtures: Import from conftest.py automatically
4. Mark tests: Use @pytest.mark.unit, @pytest.mark.integration, or @pytest.mark.slow

Example test:

import pytest

@pytest.mark.unit
def test_example_function(mock_config, temp_dir):
    # Your test implementation
    assert True

Notes

• The project uses Poetry in non-package mode since it's primarily for dependency management
• Coverage is configured but currently shows 0% as there are no source files to test yet
• All testing dependencies are properly isolated in the development group
• The infrastructure is ready for immediate test development