feat: Set up comprehensive Python testing infrastructure

[llbbl]

Set up Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the DCF77 MutterUhr project, providing a solid foundation for writing and running tests in a Python development environment.

Changes Made

Package Management

• ✅ Added Poetry configuration in pyproject.toml with project metadata and dependencies
• ✅ Configured development dependencies: pytest, pytest-cov, pytest-mock
• ✅ Set up Poetry scripts for easy test execution (poetry run test and poetry run tests)

Testing Configuration

• ✅ Comprehensive pytest configuration with:
  • Test discovery patterns for various test file naming conventions
  • Coverage reporting with 80% threshold
  • HTML and XML coverage report generation
  • Custom markers for unit, integration, and slow tests
  • Strict configuration for better test reliability

Directory Structure

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

Testing Utilities

• ✅ Comprehensive fixtures in conftest.py:
  • temp_dir - Temporary directory for file system tests
  • mock_machine_pin, mock_machine_rtc - Hardware mocking for MicroPython modules
  • mock_network - WiFi/network functionality mocking
  • mock_urequests - HTTP request mocking
  • mock_secrets - Credentials mocking
  • mock_microdot - Web framework mocking
  • Sample data fixtures for testing

Development Environment

• ✅ Updated .gitignore with comprehensive exclusions:
  • Testing artifacts (.pytest_cache/, htmlcov/, .coverage)
  • Virtual environments and build artifacts
  • IDE files and OS-specific files
  • Claude Code settings

Validation

• ✅ Created validation test suite that verifies:
  • pytest functionality and Python version compatibility
  • Project structure integrity
  • Custom test markers functionality
  • Fixture availability and mocking capabilities

How to Run Tests

Install Dependencies

poetry install

Run All Tests

poetry run pytest
# or
poetry run test
# or  
poetry run tests

Run Specific Test Categories

# 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"

Generate Coverage Reports

poetry run pytest --cov-report=html
# Open htmlcov/index.html in browser to view coverage

Notes

• MicroPython Compatibility: The main application files (main.py, webtime.py) are MicroPython-specific and excluded from standard Python coverage analysis
• Hardware Mocking: Comprehensive mocking fixtures are provided for testing code that interacts with MicroPython hardware modules
• Ready for Development: The infrastructure is immediately ready for developers to start writing unit and integration tests
• Coverage Configured: HTML and XML coverage reports are generated automatically, with an 80% coverage threshold

Testing Infrastructure Validation

All validation tests pass successfully:

• ✅ pytest functionality verified
• ✅ Python version compatibility confirmed
• ✅ Project structure validated
• ✅ Custom markers working correctly
• ✅ Shared fixtures accessible and functional
• ✅ Mocking capabilities operational

The testing infrastructure is now ready for active development and continuous integration workflows.