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 STFT Transformer project using Poetry as the package manager. The setup provides a ready-to-use testing environment where developers can immediately start writing and running tests.

Changes Made

Package Management

• Poetry Configuration: Created pyproject.toml with Poetry configuration
• Dependencies Migration: Analyzed existing Python files and added all required dependencies:
  • Core: pandas, numpy, librosa, soundfile, tqdm, pqdm, scikit-image, scikit-learn
  • ML/AI: torch, timm, scipy, matplotlib
• Testing Dependencies: Added as dev dependencies:
  • pytest (main testing framework)
  • pytest-cov (coverage reporting with 80% threshold)
  • pytest-mock (mocking utilities)

Testing Configuration

• pytest Settings: Comprehensive test discovery and execution configuration
• Coverage Reporting: Multiple formats (HTML, XML, terminal) with proper exclusions
• Custom Markers: unit, integration, and slow for test categorization
• Strict Configuration: Enforces marker and config validation

Directory Structure

tests/
├── __init__.py
├── conftest.py              # Shared fixtures
├── test_setup_validation.py # Infrastructure validation
├── unit/
│   └── __init__.py
└── integration/
    └── __init__.py

Shared Fixtures (conftest.py)

• temp_dir: Temporary directory management
• sample_audio_data: Mock audio data for testing
• sample_metadata_df: Sample pandas DataFrame
• mock_config: Configuration dictionary
• sample_paths: Directory structure setup
• mock_numpy_array & mock_spectrogram: ML testing utilities

Additional Setup

• .gitignore: Comprehensive Python project gitignore with testing entries
• Validation Tests: 10 tests verifying all infrastructure components work correctly

Running Tests

Basic Commands

# Install dependencies
poetry install

# Run all tests with coverage
poetry run pytest

# Run specific test categories
poetry run pytest -m unit          # Unit tests only
poetry run pytest -m integration   # Integration tests only  
poetry run pytest -m "not slow"    # Skip slow tests

# Generate coverage report
poetry run pytest --cov-report=html

Test Organization

• Unit tests: /tests/unit/ - Fast, isolated component tests
• Integration tests: /tests/integration/ - Cross-component interaction tests
• Custom markers: Use @pytest.mark.unit, @pytest.mark.integration, @pytest.mark.slow

Coverage Reporting

• Threshold: 80% minimum coverage required
• Reports: HTML (htmlcov/), XML (coverage.xml), and terminal output
• Exclusions: Test files, cache directories, and common patterns properly excluded

Dependencies Notes

• Python Version: Updated to ^3.9 for modern dependency compatibility
• Missing Package: audiomentations was excluded due to version conflicts - can be added manually if needed
• Lock File: poetry.lock created and should be committed (not in .gitignore)

Validation Results

✅ All 10 validation tests pass
✅ Coverage reporting works correctly
✅ Custom markers function properly
✅ Fixtures are available and functional
✅ Mock utilities integrated successfully

The testing infrastructure is now ready for development. Developers can immediately begin writing tests following the established patterns and conventions.