feat: Set up comprehensive Python testing infrastructure with Poetry

[llbbl]

Set Up Python Testing Infrastructure

Summary

This PR establishes a comprehensive testing infrastructure for the Background Matting TensorFlow project, providing a complete foundation for test-driven development and quality assurance.

Changes Made

Package Management

• Poetry Configuration: Set up Poetry as the primary package manager with pyproject.toml
• Dependency Management: Migrated to Poetry with TensorFlow and PyTorch dependencies
• Development Dependencies: Added pytest ecosystem packages (pytest, pytest-cov, pytest-mock)

Testing Structure

• Directory Structure: Created organized testing directories:
  • tests/ - Root testing directory
  • tests/unit/ - Unit tests for individual components
  • tests/integration/ - Integration tests for component interactions
  • All directories include proper __init__.py files

Testing Configuration

• pytest Configuration: Comprehensive setup in pyproject.toml including:

  • Test discovery patterns for files, classes, and functions
  • Coverage reporting (HTML, XML, terminal with missing lines)
  • Custom markers: unit, integration, slow
  • Strict configuration with verbose output
  • Warning filters for cleaner test output

• Coverage Settings:

  • Source code tracking for the model package
  • Exclusion patterns for test files, cache, and common code patterns
  • Coverage threshold set to 10% (adjustable as needed)
  • Multiple report formats (HTML in htmlcov/, XML for CI/CD)

Shared Testing Utilities

• Comprehensive Fixtures (tests/conftest.py):
  • Temporary directory creation and cleanup
  • TensorFlow tensor generation with standard shapes
  • Mock TensorFlow models and PyTorch weights
  • Configuration dictionaries for testing
  • TensorFlow state management and random seeding
  • Training mode contexts and batch testing utilities

Quality Assurance

• Infrastructure Validation: Complete test suite (test_infrastructure_validation.py) that verifies:

  • pytest functionality and marker configuration
  • Project structure and file existence
  • Fixture availability and functionality
  • Package imports (TensorFlow, model components)
  • Coverage configuration
  • Environment setup validation

• Git Configuration: Updated .gitignore with comprehensive exclusions:

  • Testing artifacts (.pytest_cache/, coverage reports)
  • Python build artifacts and virtual environments
  • IDE files and OS-specific files
  • Claude Code settings and TensorFlow/PyTorch model files

Running Tests

Basic Test Execution

# Activate virtual environment
source .venv/bin/activate

# Run all tests
python -m pytest

# Run with verbose output and coverage
python -m pytest -v

# Run specific test types
python -m pytest -m unit        # Unit tests only
python -m pytest -m integration # Integration tests only
python -m pytest -m "not slow"  # Skip slow tests

Alternative Commands

# Using Poetry scripts (when Poetry setup is complete)
poetry run test    # Standard test execution
poetry run tests   # Alternative command

Coverage Reports

• Terminal: Coverage summary displayed after each test run
• HTML Report: Detailed coverage report in htmlcov/index.html
• XML Report: Machine-readable coverage in coverage.xml (for CI/CD)

Development Workflow

1. Writing Tests: Place tests in appropriate directories:

   • tests/unit/ for component-specific tests
   • tests/integration/ for cross-component tests

2. Using Fixtures: Leverage shared fixtures from conftest.py:

   • temp_dir - Temporary directory for file operations
   • sample_tensor - Standard TensorFlow tensors
   • mock_tensorflow_model - Mock models for testing
   • config_dict - Standard configuration for model testing

3. Test Markers: Use markers to categorize tests:

   @pytest.mark.unit
   @pytest.mark.integration  
   @pytest.mark.slow

Validation

All infrastructure components have been validated:

• ✅ 12/12 validation tests passing
• ✅ Coverage reporting functional
• ✅ All fixtures working correctly
• ✅ TensorFlow and model imports successful
• ✅ Package structure verified

Notes

• Virtual Environment: Uses standard Python venv due to Poetry CUDA dependency conflicts
• Dependencies: TensorFlow and PyTorch installed for CPU-only usage (suitable for testing)
• Coverage Threshold: Set to 10% initially, can be increased as test coverage grows
• Extensible: Infrastructure designed to easily accommodate additional testing tools and frameworks

This testing infrastructure provides a solid foundation for implementing comprehensive test suites across the Background Matting codebase.