feat: Set up complete Python testing infrastructure with Poetry

[llbbl]

Set Up Python Testing Infrastructure

Summary

This PR establishes a complete testing infrastructure for the Python interview questions project using Poetry as the package manager and pytest as the testing framework.

Changes Made

Package Management

• Poetry Setup: Initialized Poetry with pyproject.toml configuration
• Dependencies: Added testing dependencies as development dependencies:
  • pytest (^8.3.3) - Core testing framework
  • pytest-cov (^5.0.0) - Coverage reporting
  • pytest-mock (^3.14.0) - Mocking utilities

Testing Configuration

• pytest Configuration:

  • Test discovery patterns for test_*.py files
  • Coverage settings with 80% threshold
  • HTML and XML coverage report generation
  • Custom markers: unit, integration, slow
  • Strict mode with detailed output

• Coverage Configuration:

  • Source directories: src, 编程题, 数据结构与算法
  • Exclusions for test files and virtual environments
  • Branch coverage enabled
  • Multiple report formats

Project Structure

tests/
├── __init__.py
├── conftest.py          # Shared fixtures and configuration
├── test_validation.py   # Infrastructure validation tests
├── unit/
│   ├── __init__.py
│   └── test_example.py  # Example unit test
└── integration/
    └── __init__.py

Development Commands

• poetry run test - Run all tests
• poetry run tests - Alternative command (both work)
• poetry run pytest [options] - Direct pytest access with all options

Shared Fixtures (in conftest.py)

• temp_dir - Temporary directory for file operations
• temp_file - Temporary file with content
• mock_env_vars - Environment variable management
• sample_data - Common test data structures
• sample_tree_node - Binary tree node for algorithm tests
• sample_linked_list_node - Linked list node for algorithm tests
• capture_stdout - Stdout capture for testing print statements
• mock_input - Mock user input for interactive code

Testing the Infrastructure

Install Dependencies

poetry install

Run Tests

# Run all tests
poetry run test

# Run with specific markers
poetry run pytest -m unit
poetry run pytest -m integration
poetry run pytest -m "not slow"

# Run validation tests
poetry run pytest tests/test_validation.py -v

View Coverage Reports

• HTML Report: htmlcov/index.html
• XML Report: coverage.xml
• Terminal Report: Automatically displayed after test run

Notes

1. Poetry Lock File: The poetry.lock file is NOT gitignored and should be committed to ensure reproducible builds.

2. Coverage Threshold: Set to 80% - tests will fail if coverage drops below this threshold.

3. Python Version: Configured for Python 3.8+ compatibility.

4. Test Organization: Tests are organized into unit/ and integration/ directories with automatic marker assignment based on location.

5. Project Packages: The src directory is configured as a package, and all Python files in the project are included in coverage analysis.

Next Steps

Developers can now immediately start writing tests for the existing codebase:

1. Create test files following the test_*.py naming convention
2. Use the provided fixtures from conftest.py
3. Mark tests appropriately with @pytest.mark.unit, @pytest.mark.integration, or @pytest.mark.slow
4. Run tests with coverage to ensure code quality