Contributing

urllib3 is a community-maintained project and we happily accept contributions.

If you wish to add a new feature or fix a bug:

  1. Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug. There is a Contributor Friendly tag for issues that should be ideal for people who are not very familiar with the codebase yet.

  2. Fork the urllib3 repository on Github to start making your changes.

  3. Write a test which shows that the bug was fixed or that the feature works as expected.

  4. Format your changes with black using command $ nox -rs format and lint your changes using command nox -rs lint.

  5. Send a pull request and bug the maintainer until it gets merged and published. :) Make sure to add yourself to CONTRIBUTORS.txt.

Setting up your development environment

In order to setup the development environment all that you need is nox installed in your machine:

$ pip install --user --upgrade nox

Running the tests

We use some external dependencies, multiple interpreters and code coverage analysis while running test suite. Our noxfile.py handles much of this for you:

$ nox --reuse-existing-virtualenvs --sessions test-3.7 test-3.9
[ Nox will create virtualenv if needed, install the specified dependencies, and run the commands in order.]
nox > Running session test-3.7
.......
.......
nox > Session test-3.7 was successful.
.......
.......
nox > Running session test-3.9
.......
.......
nox > Session test-3.9 was successful.

There is also a nox command for running all of our tests and multiple python versions.:

$ nox --reuse-existing-virtualenvs --sessions test

Note that code coverage less than 100% is regarded as a failing run. Some platform-specific tests are skipped unless run in that platform. To make sure the code works in all of urllib3’s supported platforms, you can run our tox suite:

$ nox --reuse-existing-virtualenvs --sessions test
[ Nox will create virtualenv if needed, install the specified dependencies, and run the commands in order.]
.......
.......
nox > Session test-3.6 was successful.
nox > Session test-3.7 was successful.
nox > Session test-3.8 was successful.
nox > Session test-3.9 was successful.
nox > Session test-pypy was successful.

Our test suite runs continuously on Travis CI with every pull request.

To run specific tests or quickly re-run without nox recreating the env, do the following:

$ nox --reuse-existing-virtualenvs --sessions test-3.8 -- pyTestArgument1 pyTestArgument2 pyTestArgumentN
[ Nox will create virtualenv, install the specified dependencies, and run the commands in order.]
nox > Running session test-3.8
nox > Re-using existing virtual environment at .nox/test-3-8.
.......
.......
nox > Session test-3.8 was successful.

After the -- indicator, any arguments will be passed to pytest. To specify an exact test case the following syntax also works: test/dir/module_name.py::TestClassName::test_method_name (eg.: test/with_dummyserver/test_https.py::TestHTTPS::test_simple). The following argument is another valid example to pass to pytest: -k test_methode_name. These are useful when developing new test cases and there is no point re-running the entire test suite every iteration. It is also possible to further parameterize pytest for local testing.

For all valid arguments, check the pytest documentation.

Releases

A release candidate can be created by any contributor by creating a branch named release-x.x where x.x is the version of the proposed release.

  • Update CHANGES.rst and urllib3/__init__.py with the proper version number and commit the changes to release-x.x.

  • Open a pull request to merge the release-x.x branch into the master branch.

  • Integration tests are run against the release candidate on Travis. From here on all the steps below will be handled by a maintainer so unless you receive review comments you are done here.

  • Once the pull request is squash merged into master the merging maintainer will tag the merge commit with the version number:

    • git tag -a 1.24.1 [commit sha]

    • git push origin master --tags

  • After the commit is tagged Travis will build the tagged commit and upload the sdist and wheel to PyPI and create a draft release on GitHub for the tag. The merging maintainer will ensure that the PyPI sdist and wheel are properly uploaded.

  • The merging maintainer will mark the draft release on GitHub as an approved release.