py-libp2p/docs/contributing.rst

Contributing
------------

Thank you for your interest in contributing! We welcome all contributions no matter
their size. Please read along to learn how to get started. If you get stuck, feel free
to ask for help in `Ethereum Python Discord server <https://discord.gg/GHryRvPB84>`_.

Dependencies
^^^^^^^^^^^^

The following dependencies are needed to build py-libp2p:

* `GNU Multiprecision Arithmetic Library <https://gmplib.org/>`_
* `CMake <https://cmake.org>`
* `freedesktop.org pkg-config <https://www.freedesktop.org/wiki/Software/pkg-config>`

On Debian Linux you can install them using the following command:

.. code:: sh

    sudo apt-get install cmake pkg-config libgmp-dev

On MacOS, you can install them using the following command:

.. code:: sh

   brew install cmake pkgconfig gmp

Setting the stage
~~~~~~~~~~~~~~~~~

To get started, fork the repository to your own github account, then clone it
to your development machine:

.. code:: sh

    git clone git@github.com:your-github-username/py-libp2p.git

Next, install the development dependencies. We recommend using a virtual
environment, such as `virtualenv <https://virtualenv.pypa.io/en/stable/>`_.

.. code:: sh

    cd py-libp2p
    virtualenv -p python venv
    . venv/bin/activate
    python -m pip install -e ".[dev]"
    pre-commit install

An alternative to virtualenv is to use the built-in Python3 venv module:

.. code:: sh

   cd py-libp2p
   python3 -m venv ./venv
   . venv/bin/activate
   python3 -m pip install -e ".[dev]"
   pre-commit install

Currently, on MacOS you must help the build command find and link against the
gmp library. On MacOS run the following to build py-libp2p:

.. code:: sh

   CFLAGS="`pkg-config --cflags gmp`" LDFLAGS="`pkg-config --libs gmp`" python3 -m pip install -e ".[dev]"

Requirements
^^^^^^^^^^^^

The protobuf description in this repository was generated by ``protoc`` at version
``30.1``.

Running the tests
~~~~~~~~~~~~~~~~~

A great way to explore the code base is to run the tests.

We can run all tests with:

.. code:: sh

    make test

At this time, the interop tests are not passing. You can run just the internal tests
with ``pytest tests/core``.


Code Style
~~~~~~~~~~

We use `pre-commit <https://pre-commit.com/>`_ to enforce a consistent code style across
the library. This tool runs automatically with every commit, but you can also run it
manually with:

.. code:: sh

    make lint

If you need to make a commit that skips the ``pre-commit`` checks, you can do so with
``git commit --no-verify``.

This library uses type hints, which are enforced by the ``mypy`` tool (part of the
``pre-commit`` checks). All new code is required to land with type hints, with the
exception of code within the ``tests`` directory.

Documentation
~~~~~~~~~~~~~

Good documentation will lead to quicker adoption and happier users. Please check out our
guide on
`how to create documentation for the Python Ethereum ecosystem <https://github.com/ethereum/snake-charmers-tactical-manual/blob/main/documentation.md>`_.

Adding Examples
~~~~~~~~~~~~~~~

To add a new example (e.g., identify):

1. Create a directory in ``examples/identify``
2. Create a file ``examples/identify/identify.py`` with the example code
3. Add ``__init__.py`` to make it a proper Python package (automatically discovered by find_packages() in ``setup.py``)
4. Add the example in the example list ``docs/examples.rst``
5. Add example tests in ``tests/core/examples/test_examples.py``
6. Add the example documentation in ``docs/examples.identify.rst``
7. Add a news fragment for the new release in file ``newsfragments/536.feature.rst`` (fix-id.type.rst)
8. Generate doc files with ``make docs`` or ``make linux-docs`` in linux (generates files ``libp2p.identity.identify.rst libp2p.identity.rst libp2p.identity.identify.pb.rst``)
9. Add the example to ``setup.py``:

   .. code:: python

       entry_points={
           "console_scripts": [
               "chat-demo=examples.chat.chat:main",
               "echo-demo=examples.echo.echo:main",
               "ping-demo=examples.ping.ping:main",
               "identify-demo=examples.identify.identify:main",
           ],
       }

10. Run ``make package-test`` to test the release:

    .. code:: sh

        .....
        Activate with `source /tmp/tmpb9ybjgtg/package-smoke-test/bin/activate`
        Press enter when the test has completed. The directory will be deleted.

    Then test the example:

    .. code:: sh

        source /tmp/tmpb9ybjgtg/package-smoke-test/bin/activate
        (package-smoke-test) $ identify-demo

Pull Requests
~~~~~~~~~~~~~

It's a good idea to make pull requests early on. A pull request represents the start of
a discussion, and doesn't necessarily need to be the final, finished submission.

GitHub's documentation for working on pull requests is
`available here <https://docs.github.com/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests>`_.

Once you've made a pull request, take a look at the Circle CI build status in the
GitHub interface and make sure all tests are passing. In general pull requests that
do not pass the CI build yet won't get reviewed unless explicitly requested.

If the pull request introduces changes that should be reflected in the release notes,
please add a newsfragment file as explained
`here <https://github.com/ethereum/py-libp2p/blob/main/newsfragments/README.md>`_.

If possible, the change to the release notes file should be included in the commit that
introduces the feature or bugfix.

Releasing
~~~~~~~~~

Releases are typically done from the ``main`` branch, except when releasing a beta (in
which case the beta is released from ``main``, and the previous stable branch is
released from said branch).

Final test before each release
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Before releasing a new version, build and test the package that will be released:

.. code:: sh

    git checkout main && git pull
    make package-test

This will build the package and install it in a temporary virtual environment. Follow
the instructions to activate the venv and test whatever you think is important.

You can also preview the release notes:

.. code:: sh

    towncrier --draft

Build the release notes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Before bumping the version number, build the release notes. You must include the part of
the version to bump (see below), which changes how the version number will show in the
release notes.

.. code:: sh

    make notes bump=$$VERSION_PART_TO_BUMP$$

If there are any errors, be sure to re-run make notes until it works.

Push the release to github & pypi
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

After confirming that the release package looks okay, release a new version:

.. code:: sh

    make release bump=$$VERSION_PART_TO_BUMP$$

This command will:

- Bump the version number as specified in ``.pyproject.toml`` and ``setup.py``.
- Create a git commit and tag for the new version.
- Build the package.
- Push the commit and tag to github.
- Push the new package files to pypi.

Which version part to bump
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

``$$VERSION_PART_TO_BUMP$$`` must be one of: ``major``, ``minor``, ``patch``, ``stage``,
or ``devnum``.

The version format for this repo is ``{major}.{minor}.{patch}`` for stable, and
``{major}.{minor}.{patch}-{stage}.{devnum}`` for unstable (``stage`` can be alpha or
beta).

If you are in a beta version, ``make release bump=stage`` will switch to a stable.

To issue an unstable version when the current version is stable, specify the new version
explicitly, like ``make release bump="--new-version 4.0.0-alpha.1"``

You can see what the result of bumping any particular version part would be with
``bump-my-version show-bump``