py-test-creator — Skill Documentation

Overview

py-test-creator is an OpenClaw skill that automatically generates comprehensive pytest unit test templates from Python code. It parses function signatures, type hints, and docstrings to create actionable test scaffolding that covers edge cases and parameter combinations.

Key features:

Parse Python functions with complex signatures (defaults, type hints, variadic args)
Generate pytest-compatible test methods with proper assertions
Handle both standalone functions and class methods
Convert docstrings into test method documentation
Create ready-to-use test files with correct imports and structure

Installation

Dependencies are managed via package.json. Install with:

npm install

This will install the required Python packages (pytest, ast-parser utilities) and Node.js dependencies for the skill runner.

Usage

Trigger the skill with natural language:

"Create unit tests for this Python function"
"Generate test templates from these function signatures"
"Write pytest tests for my Python methods"
"Create unit test scaffolding from docstrings"

The skill expects a Python file or code snippet as input and produces a corresponding test file.

Input/Output

Input:
A Python file path or raw code containing one or more functions/methods.

Output:
A test file (e.g., test_<original>.py) containing pytest test functions with:

import pytest statements
Test fixtures for common parameter types
Edge case coverage (None values, boundaries, invalid types)
Parametrized tests where appropriate
Docstrings explaining test purpose

Example:

Input (utils.py):

def add(a: int, b: int) -> int:
    """Add two integers and return the result."""
    return a + b

Output (test_utils.py):

import pytest
from utils import add

def test_add_basic_integers():
    """Test add function with basic positive integers."""
    assert add(1, 2) == 3

def test_add_negative_numbers():
    """Test add function with negative integers."""
    assert add(-1, -2) == -3

def test_add_zero():
    """Test add function with zero."""
    assert add(0, 5) == 5
    assert add(5, 0) == 5

def test_add_large_numbers():
    """Test add function with large integers."""
    assert add(1000000, 2000000) == 3000000

Configuration

No configuration required. The skill uses default pytest conventions.

Optional environment variables:

PYTEST_STRICT: Set to true to enable strict mark handling
TEST_COVERAGE: Set to true to include coverage hints in generated tests

Error Handling

The skill exits with non-zero status on:

Invalid Python syntax
Missing input file/code
Permission errors writing output
AST parsing failures

Error messages are logged to stderr.

Limitations

Out of scope:

Running or validating generated tests
Integration/end-to-end testing
Multi-language support (Python only)
CI/CD integration
Performance optimization of tests

Files

The skill package includes:

skill/
├── SKILL.md           # This documentation
├── package.json       # NPM package definition
├── README.md          # Quick start guide
└── scripts/
    ├── main.py        # CLI entry point
    ├── parser.py      # Python AST parser
    ├── generator.py   # Test template generator
    └── cli.py         # Command-line interface

Skill