feat: Add comprehensive Python testing infrastructure with Poetry

[llbbl]

Add Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the OpenOOD project using Poetry as the package manager and pytest as the testing framework. The setup provides a solid foundation for writing and running tests with proper coverage reporting and development tooling.

Changes Made

Package Management

• Poetry Setup: Created pyproject.toml with Poetry configuration
• Dependency Migration: Migrated all dependencies from setup.py to Poetry
• Lock File: Generated poetry.lock for reproducible builds
• Compatibility Fix: Replaced faiss-gpu with faiss-cpu for better cross-platform compatibility

Testing Framework

• Testing Dependencies: Added pytest (^7.4.0), pytest-cov (^4.1.0), and pytest-mock (^3.11.1)
• Coverage Configuration:
  • Configured coverage reporting with HTML, XML, and terminal output
  • Set coverage threshold to 0% temporarily (TODO: increase to 80% once tests are written)
  • Excluded test files and init.py from coverage
• Test Discovery: Configured proper test discovery patterns
• Custom Markers: Added unit, integration, and slow test markers

Project Structure

tests/
├── __init__.py
├── conftest.py              # Shared pytest fixtures
├── test_infrastructure_validation.py  # Validation tests
├── unit/
│   └── __init__.py
└── integration/
    └── __init__.py

Fixtures (conftest.py)

Created comprehensive fixtures for common testing needs:

• temp_dir: Temporary directory management
• mock_config: Configuration dictionaries
• sample_tensor, sample_labels, sample_features: PyTorch tensors
• mock_model: Simple neural network for testing
• yaml_config_file, json_config_file: Config file generation
• mock_checkpoint: Model checkpoint files
• mock_dataloader: DataLoader instances
• sample_ood_scores: OOD detection scores
• And many more...

Development Experience

• Poetry Scripts: Added both poetry run test and poetry run tests commands
• Git Ignore: Updated .gitignore with Claude settings and clarified that poetry.lock should be committed
• Validation Tests: Created comprehensive validation tests to verify the infrastructure setup

Testing Instructions

1. Install dependencies:

   poetry install
   

2. Run validation tests:

   poetry run pytest tests/test_infrastructure_validation.py -v
   

3. Run all tests with coverage:

   poetry run test
   # or
   poetry run tests
   

4. 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"
   

5. View coverage reports:

   • Terminal: Automatically shown when running tests
   • HTML: Open htmlcov/index.html in a browser
   • XML: Available at coverage.xml for CI integration

Next Steps

1. Write Unit Tests: Start adding unit tests for individual components in tests/unit/
2. Write Integration Tests: Add integration tests in tests/integration/
3. Increase Coverage Threshold: Once tests are written, update --cov-fail-under from 0 to 80 in pyproject.toml
4. CI Integration: Use the generated coverage.xml for CI coverage reporting

Notes

• The infrastructure is fully set up and validated - developers can immediately start writing tests
• All pytest features are available including fixtures, markers, parametrization, etc.
• Coverage is configured but threshold is set to 0% until actual tests are written
• The validation test file demonstrates proper test structure and fixture usage