feat: Add comprehensive Python testing infrastructure with Poetry

[llbbl]

Add Complete Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the PyGAD CNN project, providing a solid foundation for test-driven development and continuous integration.

Changes Made

Package Management

• Poetry Setup: Configured Poetry as the primary package manager via pyproject.toml
• Dependency Migration: Migrated existing dependencies from requirements.txt to Poetry
• Lock File: Generated poetry.lock for reproducible builds

Testing Framework

• pytest: Added as the main testing framework with extensive configuration
• pytest-cov: Integrated for code coverage reporting
• pytest-mock: Included for advanced mocking capabilities

Project Structure

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

Configuration (pyproject.toml)

• Test Discovery: Configured patterns for test files and functions
• Coverage Settings:
  • 80% minimum coverage threshold
  • HTML and XML report generation
  • Exclusions for test files and virtual environments
• Custom Markers: @pytest.mark.unit, @pytest.mark.integration, @pytest.mark.slow
• Script Commands: Both poetry run test and poetry run tests work

Shared Fixtures (conftest.py)

• temp_dir: Temporary directory management
• sample_input_data & sample_output_data: CNN test data
• mock_config: Configuration dictionary for testing
• sample_conv_layer & sample_pool_layer: Layer configurations
• reset_random_seed: Ensures reproducible tests
• capture_stdout: For testing print statements
• mock_file_operations: File I/O mocking

Development Environment

• Updated .gitignore: Added Python-specific patterns, testing artifacts, and Claude settings
• Coverage Reports: Automatically generated in htmlcov/ and coverage.xml

Running Tests

Install Dependencies

poetry install

Run All Tests

poetry run test
# or
poetry run tests

Run Specific Test Types

# Unit tests only
poetry run pytest -m unit

# Integration tests only  
poetry run pytest -m integration

# Exclude slow tests
poetry run pytest -m "not slow"

View Coverage Report

# Generate and open HTML coverage report
poetry run test
open htmlcov/index.html

Notes

• The validation tests confirm all infrastructure components work correctly
• Coverage is currently low (13.65%) as only validation tests exist - this is expected
• The 80% coverage threshold will encourage comprehensive testing as the codebase grows
• Poetry.lock is tracked in git for reproducible environments across developers

Next Steps

Developers can now immediately start writing unit and integration tests for the CNN implementation using the established infrastructure.