We'd love to accept your patches and contributions to this project. There are just a few small guidelines you need to follow.
Before we can work on the code, we need to get a copy of it and setup some local environment and tools.
First, fork the code to your user and clone your fork. This gives you a private playground where you can do any edits you‘d like. For this guide, we’ll use the GitHub gh tool (Linux install). (More advanced users may prefer the GitHub UI and raw git commands).
gh repo fork bazelbuild/rules_python --clone --remote
Next, make sure you have a new enough version of Python installed that supports the various code formatters and other devtools. For a quick start, install pyenv and at least Python 3.9.15:
curl https://pyenv.run | bash pyenv install 3.9.15 pyenv shell 3.9.15
It's suggested that you create what is called a “feature/topic branch” in your fork when you begin working on code you want to eventually send or code review.
git checkout main # Start our branch from the latest code git checkout -b my-feature # Create and switch to our feature branch git push origin my-feature # Cause the branch to be created in your fork.
From here, you then edit code and commit to your local branch. If you want to save your work to github, you use git push to do so:
git push origin my-feature
Once the code is in your github repo, you can then turn it into a Pull Request to the actual rules_python project and begin the code review process.
Running tests is particularly easy thanks to Bazel, simply run:
bazel test //...
And it will run all the tests it can find. The first time you do this, it will probably take long time because various dependencies will need to be downloaded and setup. Subsequent runs will be faster, but there are many tests, and some of them are slow. If you're working on a particular area of code, you can run just the tests in those directories instead, which can speed up your edit-run cycle.
Note that there are tests to verify generated documentation is correct -- if you‘re modifying the signature of a public function, these tests will likely fail and you’ll need to regenerate the api docs.
Starlark files should be formatted by buildifier. Otherwise the Buildkite CI will fail with formatting/linting violations. We suggest using a pre-commit hook to automate this. First install pre-commit, then run
pre-commit install
You can also run buildifier manually. To do this, install buildifier, and run the following command:
$ buildifier --lint=fix --warnings=native-py -warnings=all WORKSPACE
Replace the argument “WORKSPACE” with the file that you are linting.
Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution, this simply gives us permission to use and redistribute your contributions as part of the project. Head over to https://cla.developers.google.com/ to see your current agreements on file or to sign a new one.
You generally only need to submit a CLA once, so if you‘ve already submitted one (even if it was for a different project), you probably don’t need to do it again.
All submissions, including submissions by project members, require review. We use GitHub pull requests for this purpose. Consult GitHub Help for more information on using pull requests.
Some checked-in files are generated and need to be updated when a new PR is merged.
To regenerate the content under the docs/ directory, run this command:
bazel run //docs:update
This needs to be done whenever the docstrings in the corresponding .bzl files are changed; a test failure will remind you to run this command when needed.
The bulk of this repo is owned and maintained by the Bazel Python community. However, since the core Python rules (py_binary and friends) are still bundled with Bazel itself, the Bazel team retains ownership of their stubs in this repository. This will be the case at least until the Python rules are fully migrated to Starlark code.
Practically, this means that a Bazel team member should approve any PR concerning the core Python logic. This includes everything under the python/ directory except for pip.bzl and requirements.txt.
Issues should be triaged as follows:
Anything concerning the way Bazel implements the core Python rules should be filed under bazelbuild/bazel, using the label team-Rules-python.
If the issue specifically concerns the rules_python stubs, it should be filed here in this repository and use the label core-rules.
Anything else, such as feature requests not related to existing core rules functionality, should also be filed in this repository but without the core-rules label.
git commitIf you did pre-commit install, various tools are run when you do git commit. This might show as an error such as:
[INFO] Installing environment for https://github.com/psf/black. [INFO] Once installed this environment will be reused. [INFO] This may take a few minutes... An unexpected error has occurred: CalledProcessError: command: ...
To fix, you‘ll need to figure out what command is failing and why. Because these are tools that run locally, its likely you’ll need to fix something with your environment or the installation of the tools. For Python tools (e.g. black or isort), you can try using a different Python version in your shell by using tools such as pyenv.