Atheris Fuzz Driver Generator

Generates fuzz.py harness files for Python libraries with proper Atheris instrumentation, FuzzedDataProvider usage, and exception handling.

Driver Design Principles

1. Import target library inside atheris.instrument_imports() context manager
2. Use FuzzedDataProvider to generate structured typed inputs
3. Catch only expected exceptions (ValueError, TypeError, domain-specific errors)
4. Guard with if __name__ == "__main__": block
5. Use atheris.Setup(sys.argv, TestOneInput) then atheris.Fuzz()

Supported Libraries

• arrow: Date/time parsing, timestamp boundary testing
• black: Code formatting with Mode configuration
• ipython: Input transformation pipeline
• minisgl: JSON/msgpack parsing (lightweight targets)
• ujson: Differential fuzzing against stdlib json

Key Functions

• generate_fuzz_driver(lib_path) - Generate and write fuzz.py for a library
• get_driver_template(lib_name) - Get driver source code for a library
• get_exception_handlers_for_lib(lib_name) - Get expected exceptions list
• create_fuzz_driver_file(lib_path, lib_name) - Write fuzz.py to disk

Usage

import sys
sys.path.insert(0, '/app/environment/skills/evo-atheris-fuzz-driver/scripts')
from fuzz_driver import generate_fuzz_driver, create_fuzz_driver_file

generate_fuzz_driver('/app/arrow')
generate_fuzz_driver('/app/black')