argon2-cffi/.github/CONTRIBUTING.md

How To Contribute

First off, thank you for considering contributing! It's people like you who make it is such a great tool for everyone.

This document is mainly to help you to get started by codifying tribal knowledge and expectations and make it more accessible to everyone. But don't be afraid to open half-finished PRs and ask questions if something is unclear!

Workflow

• No contribution is too small! Please submit as many fixes for typos and grammar bloopers as you can!
• Try to limit each pull request to one change only.
• Since we squash on merge, it's up to you how you handle updates to the main branch. Whether you prefer to rebase on main or merge main into your branch, do whatever is more comfortable for you.
• Always add tests and docs for your code. This is a hard rule; patches with missing tests or documentation can't be merged.
• Make sure your changes pass our CI. You won't get any feedback until it's green unless you ask for it.
• For the CI to pass, the coverage must be 100%. If you have problems to test something, open anyway and ask for advice. In some situations, we may agree to add an # pragma: no cover.
• Once you've addressed review feedback, make sure to bump the pull request with a short note, so we know you're done.
• Don’t break backwards-compatibility.

Local development environment

First, fork the repository on GitHub and clone it using one of the alternatives that you can copy-paste by pressing the big green button labeled <> Code.

You can (and should) run our test suite using tox. However, you'll probably want a more traditional environment as well.

We recommend using the Python version from the .python-version-default file in the project's root directory, because that's the one that is used in the CI by default, too.

If you're using direnv, you can automate the creation of the project virtual environment with the correct Python version by adding the following .envrc to the project root:

layout python python$(cat .python-version-default)

or, if you like uv:

test -d .venv || uv venv --python python$(cat .python-version-default)
. .venv/bin/activate

Warning

• Before you start working on a new pull request, use the "Sync fork" button in GitHub's web UI to ensure your fork is up to date.
• Always create a new branch off main for each new pull request. Yes, you can work on main in your fork and submit pull requests. But this will inevitably lead to you not being able to synchronize your fork with upstream and having to start over.

Change into the newly created directory and after activating a virtual environment, install an editable version of this project along with its tests requirements:

$ pip install -e . --group dev  # or `uv pip install -e . --group dev`

Now you can run the test suite:

$ python -Im pytest

When working on the documentation, use:

$ tox run -e docs-watch

This will build the documentation, and then watch for changes and rebuild it whenever you save a file.

To just build the documentation and run doctests, use:

$ tox run -e docs

You will find the built documentation in docs/_build/html.

To avoid committing code that violates our style guide, we strongly advise you to install pre-commit and its hooks:

$ pre-commit install

This is not strictly necessary, because our tox file contains an environment that runs:

$ pre-commit run --all-files

and our CI has integration with pre-commit.ci. But it's way more comfortable to run it locally and git catching avoidable errors.

Code

• Obey PEP 8 and PEP 257. We use the """-on-separate-lines style for docstrings and Napoleon for parsing them:

  def func(x: str, y: bool) -> int:
      """
      Do something.
  
      Args:
          x: A very important parameter.
  
          y:
              Another important parameter whose description is too long for one
              line, therefore it starts on the next line.
  
      Returns:
          Something!
      """
  

• If you add or change public APIs, tag the docstring using .. versionadded:: 16.0.0 WHAT or .. versionchanged:: 16.2.0 WHAT.

• We use Ruff to sort our imports and format our code with a line length of 79 characters. As long as you run our full tox suite before committing, or install our pre-commit hooks (ideally you'll do both – see Local Development Environment above), you won't have to spend any time on formatting your code at all. If you don't, CI will catch it for you – but that seems like a waste of your time!

Tests

• Write your asserts as expected == actual to line them up nicely:

  x = f()
  
  assert 42 == x.some_attribute
  assert "foo" == x._a_private_attribute
  

• 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 in our CI.

• Write good test docstrings.

Documentation

• Use semantic newlines in reStructuredText and Markdown files (files ending in .rst and .md):

  This is a sentence.
  This is another sentence.
  

Changelog

If your change is noteworthy, there needs to be a changelog entry in CHANGELOG.md.

• The changelog follows the Keep a Changelog standard. Please add the best-fitting section if it's missing for the current release. We use the following order: Security, Removed, Deprecated, Added, Changed, Fixed.

• As with other docs, please use semantic newlines in the changelog.

• Make the last line a link to your pull request. You probably have to open it first to know the number.

• Wrap symbols like modules, functions, or classes into backticks so they are rendered in a monospace font.

• Wrap arguments into asterisks like in docstrings: Added new argument *an_argument*.

• If you mention functions or other callables, add parentheses at the end of their names: argon2_cffi.func() or argon2_cffi.Class.method(). This makes the changelog a lot more readable.

• Prefer simple past tense or constructions with "now". For example:

  • Added argon2_cffi.func().
  • argon2_cffi.func() now doesn't crash the Large Hadron Collider anymore when passed the foobar argument.

Example entries

Added `argon2_cffi.func()`.
The feature really *is* awesome.

or:

`argon2_cffi.func()` now doesn't crash the Large Hadron Collider anymore when passed the *foobar* argument.
The bug really *was* nasty.

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Again, this list is mainly to help you to get started by codifying tribal knowledge and expectations. If something is unclear, feel free to ask for help!

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.