# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Build/Test Commands
- Build: `make build`
- Run all tests: `make check`
- Run single test: `PYTHONPATH=$(pwd) python3 -m unittest tests.test_module_name.TestClassName.test_method_name`
- Type checking: `make typing` or `python3 -m mypy dulwich`
- Lint code: `make style` or `ruff check .`
- Fix lint issues: `make fix` or `ruff check --fix .`
- Format code: `make reformat` or `ruff format .`
- Generate coverage: `make coverage` or `make coverage-html` for HTML report

## Code Style Guidelines
- Follow PEP8 with accommodations listed in `pyproject.toml` (ruff config)
- Use Google-style docstrings for public methods, functions and classes
- Triple quotes should always be """, single quotes are ' (unless " reduces escaping)
- Git paths/filenames are treated as bytestrings (bytes), not unicode strings
- On-disk filenames: use regular strings or pathlib.Path objects
- Ensure all functionality is available in pure Python (Rust implementations optional)
- Add unit tests for new functionality and bug fixes
- All contributions must be under Apache License 2.0+ or GPL 2.0+
- When adding new test files, ensure the test accumulation functions are updated
  (i.e. ``self_test_suite()`` in `tests/__init__.py` or ``test_suite()`` in `tests/compat/__init__.py`)
- Do not ignore exceptions. Never catch ``Exception`` unless you're going to
  re-raise it, always something more specific. Catch specific exceptions. Don't catch OSError, but specific subclasses.
- Keep code in try/except blocks to a minimum, and use else:. This keeps the code that can raise an exception
  to a minimum.
- There is almost never a good reason to catch AttributeError.