# How To Contribute

Every open source project lives from the generous help by contributors that sacrifice their time and `argon2_cffi` is no different.

Here are a few guidelines to get you started:

- If you want to install a development version of `argon2_cffi` into your current `virtualenv`, you have to remember to:

  1. `git submodule init` (to initialize git submodule mechanics)
  2. `git submodule update` (to update the vendored Argon2 C library to the version `argon2_cffi` is currently packaging)
  3. `python setup.py build` (to build the CFFI module)
  4. `pip install -e .[dev]` (to [re-]install it along with the Python code and test dependencies)

  You have to perform steps 2, 3, and 4 whenever something changes in the Argon2 C code (e.g. if the vendored code has been updated).

- Try to limit each pull request to one change only.

- To run the test suite, all you need is a recent tox. It will ensure the test suite runs with all dependencies against all Python versions just as it will on Travis CI. If you lack some Python versions, you can can make it a non-failure using `tox --skip-missing-interpreters` (in that case you may want to look into pyenv that makes it very easy to install many different Python versions in parallel).

  One of the environments requires a system-wide installation of Argon2. On macOS, it’s available in Homebrew and recent Ubuntus (zesty and later) ship it too.

- Make sure your changes pass our CI. You won’t get any feedback until it’s green unless you ask for it.

- Once you’ve addressed review feedback, make sure to bump the pull request with a short note, so we know you’re done.

- If your change is noteworthy, add an entry to the changelog. Use semantic newlines and add a link to your pull request.

- No contribution is too small; please submit as many fixes for typos and grammar bloopers as you can!

- Don’t break backward compatibility.

- Always add tests and docs for your code. This is a hard rule; patches with missing tests or documentation won’t be merged.

- Write good test docstrings.

- Obey PEP 8 and PEP 257.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. Please report any harm to Hynek Schlawack in any way you find appropriate.

Thank you for considering to contribute!