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 reach for help in our Gitter channel.
Setting the stage
First we need to clone the Py-EVM repository. Py-EVM depends on a submodule of the common tests across all clients, so we need to clone the repo with the --recursive
flag. Example:
$ git clone --recursive https://github.com/ethereum/py-evm.git
Optional: Often, the best way to guarantee a clean Python 3 environment is with
virtualenv. If we don’t have virtualenv
installed
already, we first need to install it via pip.
pip install virtualenv
Then, we can initialize a new virtual environment venv
, like:
virtualenv -p python3 venv
This creates a new directory venv
where packages are installed isolated from any other global
packages.
To activate the virtual directory we have to source it
. venv/bin/activate
After we have activated our virtual environment, we need to install all dependencies that are needed to run, develop, and test. This is as easy as navigating to the py-evm directory and running:
pip install -e ".[dev]"
Running the tests
A great way to explore the code base is to run the tests.
We can run all tests with:
pytest tests
However, running the entire test suite does take a very long time so often we just want to run a subset instead, like:
pytest tests/core/padding-utils/test_padding.py
We can also install tox
to run the full test suite which also covers things like testing the code against different Python versions, linting etc.
It is important to understand that each Pull Request must pass the full test suite as part of the CI check, hence it is often convenient to have tox
installed locally as well.
Code Style
When multiple people are working on the same body of code, it is important that they write code that conforms to a similar style. It often doesn’t matter as much which style, but rather that they conform to one style.
To ensure your contribution conforms to the style being used in this project, we encourage you to read our style guide.
Type Hints
The code bases is transitioning to use type hints. Type hints make it easy to prevent certain types of bugs, enable richer tooling and enhance the documentation, making the code easier to follow.
All new code is required to land with type hints with the exception of test code that is not expected to use type hints.
All parameters as well as the return type of defs are expected to be typed with the exception of self
and cls
as seen in the following example.
def __init__(self, wrapped_db: DatabaseAPI) -> None:
self.wrapped_db = wrapped_db
self.reset()
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.
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.
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.
If possible, the change to the release notes file should be included in the commit that introduces the feature or bugfix.
Releasing
Final test before each release
Before releasing a new version, build and test the package that will be released:
git checkout main && git pull
make package
# Preview the upcoming release notes
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.
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:
make release bump=$$VERSION_PART_TO_BUMP$$
Which version part to bump
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).
During a release, specify which part to bump, like
make release bump=minor
or make release bump=devnum
.
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 devnum"