feat: Set up comprehensive Python testing infrastructure with Poetry

[llbbl]

Python Testing Infrastructure Setup

Summary

This PR establishes a comprehensive testing infrastructure for the project using Poetry as the package manager and pytest as the testing framework. The setup provides a ready-to-use environment where developers can immediately start writing unit and integration tests.

Changes Made

Package Management

• Poetry Configuration: Created pyproject.toml with Poetry as the package manager
• Dependency Migration: Migrated existing dependencies from requirements.txt
• Lock File: Generated poetry.lock for reproducible installations

Testing Framework

• pytest: Main testing framework with plugins:
  • pytest-cov: Coverage reporting with HTML and XML output
  • pytest-mock: Mocking utilities for test isolation
• Configuration: Comprehensive pytest settings in pyproject.toml:
  • Test discovery patterns
  • Coverage thresholds (currently 0%, should be updated to 80% after writing tests)
  • Custom markers for test categorization
  • Strict mode and verbose output

Directory Structure

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

Shared Fixtures (conftest.py)

• temp_dir: Temporary directory with automatic cleanup
• mock_config: Mock configuration dictionary
• sample_point_cloud: Test 3D point cloud data
• sample_image_data: Test image arrays
• mock_camera_params: Camera parameter fixtures
• temp_ply_file: Temporary PLY file generation
• mock_training_args: Training argument mocks
• capture_stdout: Stdout capturing for testing prints
• reset_random_seed: Reproducible random seeds
• mock_gaussian_model_data: Gaussian model test data
• environment_setup: Test environment configuration

Development Workflow

• Commands: Both poetry run test and poetry run tests work
• Markers: Tests can be marked as @pytest.mark.unit, @pytest.mark.integration, or @pytest.mark.slow
• Coverage: Automatic coverage reporting in HTML and XML formats

Additional Setup

• CLAUDE.md: Created project context file for Claude Code
• .gitignore: Updated with comprehensive Python testing patterns

Instructions for Running Tests

1. Install Poetry (if not already installed):

   curl -sSL https://install.python-poetry.org | python3 -

2. Install Dependencies:

   poetry install

3. Run Tests:

   poetry run test
   # or
   poetry run tests

4. Run Specific Test Categories:

   poetry run pytest -m unit        # Run only unit tests
   poetry run pytest -m integration # Run only integration tests
   poetry run pytest -m "not slow"  # Skip slow tests

5. View Coverage Report:

   • HTML report: Open htmlcov/index.html in a browser
   • Terminal report: Automatically displayed after test run
   • XML report: Available at coverage.xml for CI integration

Important Notes

• Coverage Threshold: Currently set to 0% to allow infrastructure setup. Update line 44 in pyproject.toml from "--cov-fail-under=0" to "--cov-fail-under=80" after writing actual tests.
• Dependencies: Some packages (open3d, pytorch3d) were excluded due to platform compatibility issues. These can be added back with platform-specific configurations if needed.
• Poetry Lock: The poetry.lock file is tracked in git for reproducible builds.

Next Steps

1. Write unit tests for individual modules in tests/unit/
2. Write integration tests for system components in tests/integration/
3. Update coverage threshold to 80% once tests are written
4. Configure CI/CD to run tests automatically