feat: Set up comprehensive Python testing infrastructure

[llbbl]

Set up Python Testing Infrastructure

Summary

This PR sets up a comprehensive testing infrastructure for the Extra Image List Blender addon, providing a complete development environment for writing and running tests.

Changes Made

Package Management

• Poetry Setup: Added pyproject.toml with Poetry configuration for dependency management
• Testing Dependencies: Added pytest, pytest-cov, and pytest-mock as development dependencies
• Package Mode: Configured as library mode since this is a Blender addon, not a standalone package

Testing Configuration

• Pytest Configuration: Comprehensive pytest settings in pyproject.toml including:
  • Test discovery patterns for test_*.py and *_test.py files
  • Strict configuration for markers and config validation
  • Custom markers: unit, integration, and slow
  • Verbose output by default

Coverage Reporting

• Coverage Settings: Configured with 80% coverage threshold
• Multiple Report Formats: HTML (htmlcov/), XML (coverage.xml), and terminal output
• Smart Exclusions: Excludes test files, virtual environments, build artifacts, and the main Blender module

Directory Structure

tests/
├── __init__.py
├── conftest.py          # Shared fixtures and test configuration
├── unit/                # Fast, isolated unit tests
│   └── __init__.py
├── integration/         # Slower tests with dependencies
│   └── __init__.py
└── test_setup_validation.py  # Validation tests for the infrastructure

Shared Fixtures (conftest.py)

• Temporary File System: temp_dir and temp_file fixtures for test isolation
• Blender Mocking: Comprehensive mocks for bpy module and Blender contexts
• Test Data: Sample image lists, configurations, and operator mocks
• Environment Management: Automatic environment cleanup and isolation

Development Workflow

• Run All Tests: poetry run pytest
• Run with Coverage: poetry run pytest --cov
• Run Unit Tests Only: poetry run pytest -m "unit"
• Run Without Slow Tests: poetry run pytest -m "not slow"
• Generate HTML Coverage Report: Coverage reports automatically generated in htmlcov/

Git Integration

• Updated .gitignore: Added entries for testing artifacts, coverage reports, virtual environments, and Claude settings
• Preserved Lock Files: Poetry lock files are tracked for reproducible builds

Testing Infrastructure Validation

The setup includes a comprehensive validation test suite (test_setup_validation.py) that verifies:

✅ Basic pytest functionality (assertions, parametrized tests)
✅ All fixtures work correctly (temp files, Blender mocks, test data)
✅ Mocking capabilities (unittest.mock, patches, MagicMock)
✅ Test markers function (unit, integration, slow)
✅ Coverage reporting (branch coverage, exclusions)
✅ Error handling (exception testing, message validation)
✅ Data-driven testing (parametrized test cases)

Test Results: 31 tests pass, demonstrating that all infrastructure components are working correctly.

Usage Instructions

Initial Setup

# Install dependencies
poetry install --no-root

# Run all tests
poetry run pytest

# Run tests with coverage
poetry run pytest --cov

# Run specific test types
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

Coverage Reports

• Terminal: Coverage summary shown after test run
• HTML Report: Open htmlcov/index.html in browser for detailed coverage
• XML Report: coverage.xml for CI/CD integration

Writing Tests

• Unit tests: Place in tests/unit/ for fast, isolated tests
• Integration tests: Place in tests/integration/ for tests with dependencies
• Use fixtures: Leverage shared fixtures from conftest.py for common test data
• Mark slow tests: Use @pytest.mark.slow for tests that take significant time

Notes

• Blender Compatibility: The testing infrastructure is designed specifically for Blender addons with comprehensive bpy module mocking
• No Production Dependencies: All testing dependencies are in the [tool.poetry.group.test] section
• Ready for CI/CD: Configuration supports automated testing with coverage reporting in standard formats
• Extensible: Easy to add new fixtures, markers, and test utilities as the project grows

🤖 Generated with Claude Code