Contributing ============ Process ------- As an open source project, ``cryptography`` welcomes contributions of all forms. These can include: * Bug reports and feature requests * Pull requests for both code and documentation * Patch reviews You can file bugs and submit pull requests on `GitHub`_. To discuss larger changes you can start a conversation on `our mailing list`_. Because cryptography is so complex, and the implications of getting it wrong so devastating, ``cryptography`` has a strict code review policy: * Patches must *never* be pushed directly to ``master``, all changes (even the most trivial typo fixes!) must be submitted as a pull request. * A committer may *never* merge their own pull request, a second party must merge their changes. If multiple people work on a pull request, it must be merged by someone who did not work on it. * A patch which breaks tests, or introduces regressions by changing or removing existing tests should not be merged. Tests must always be passing on ``master``. * If somehow the tests get into a failing state on ``master`` (such as by a backwards incompatible release of a dependency) no pull requests may be merged until this is rectified. The purpose of these policies is to minimize the chances we merge a change which jeopardizes our users' security. If you believe you've identified a security issue in ``cryptography``, please follow the directions on the :doc:`security page `. Code ---- When in doubt, refer to `PEP 8`_ for Python code. Every code file must start with the boilerplate notice of the Apache License. Additionally, every Python code file must contain .. code-block:: python from __future__ import absolute_import, division, print_function C bindings ---------- When binding C code with ``cffi`` we have our own style guide, it's pretty simple. Don't name parameters: .. code-block:: c // Good long f(long); // Bad long f(long x); ...unless they're inside a struct: .. code-block:: c struct my_struct { char *name; int number; ...; }; Don't include stray ``void`` parameters: .. code-block:: c // Good long f(); // Bad long f(void); Wrap lines at 80 characters like so: .. code-block:: c // Pretend this went to 80 characters long f(long, long, int *) Include a space after commas between parameters: .. code-block:: c // Good long f(int, char *) // Bad long f(int,char *) Documentation ------------- All features should be documented with prose. Docstrings should be written like this: .. code-block:: python def some_function(some_arg): """ Does some things. :param some_arg: Some argument. """ So, specifically: * Always use three double quotes. * Put the three double quotes on their own line. * No blank line at the end. * Use Sphinx parameter/attribute documentation `syntax`_. When documenting a new module in the ``hazmat`` package, its documentation should begin with the "Hazardous Materials" warning: .. code-block:: rest .. hazmat:: Development Environment ----------------------- Working on ``cryptography`` requires the installation of a small number of development dependencies. These are listed in ``dev-requirements.txt`` and they can be installed in a `virtualenv`_ using `pip`_. Once you've installed the dependencies, install ``cryptography`` in ``editable`` mode. For example: .. code-block:: console $ # Create a virtualenv and activate it $ pip install --requirement dev-requirements.txt $ pip install --editable . You are now ready to run the tests and build the documentation. Running Tests ------------- ``cryptography`` unit tests are found in the ``tests/`` directory and are designed to be run using `pytest`_. `pytest`_ will discover the tests automatically, so all you have to do is: .. code-block:: console $ py.test ... 4294 passed in 15.24 seconds This runs the tests with the default Python interpreter. You can also verify that the tests pass on other supported Python interpreters. For this we use `tox`_, which will automatically create a `virtualenv`_ for each supported Python version and run the tests. For example: .. code-block:: console $ tox ... ERROR: py26: InterpreterNotFound: python2.6 py27: commands succeeded ERROR: pypy: InterpreterNotFound: pypy ERROR: py32: InterpreterNotFound: python3.2 py33: commands succeeded docs: commands succeeded pep8: commands succeeded You may not have all the required Python versions installed, in which case you will see one or more ``InterpreterNotFound`` errors. Building Documentation ---------------------- ``cryptography`` documentation is stored in the ``docs/`` directory. It is written in `reStructured Text`_ and rendered using `Sphinx`_. Use `tox`_ to build the documentation. For example: .. code-block:: console $ tox -e docs ... docs: commands succeeded congratulations :) The HTML documentation index can now be found at ``docs/_build/html/index.html`` .. _`GitHub`: https://github.com/pyca/cryptography .. _`our mailing list`: https://mail.python.org/mailman/listinfo/cryptography-dev .. _`PEP 8`: http://www.peps.io/8/ .. _`syntax`: http://sphinx-doc.org/domains.html#info-field-lists .. _`pytest`: https://pypi.python.org/pypi/pytest .. _`tox`: https://pypi.python.org/pypi/tox .. _`virtualenv`: https://pypi.python.org/pypi/virtualenv .. _`pip`: https://pypi.python.org/pypi/pip .. _`sphinx`: https://pypi.python.org/pypi/sphinx .. _`reStructured Text`: http://docutils.sourceforge.net/rst.html