Contribution getting started¶

Contributions are highly welcomed and appreciated. Every little help counts, so do not hesitate!

Contents

Contribution getting started

Feature requests and feedback¶

Do you like pytest? Share some love on Twitter or in your blog posts!

We’d also like to hear about your propositions and suggestions. Feel free to submit them as issues and:

Explain in detail how they should work.
Keep the scope as narrow as possible. This will make it easier to implement.

Report bugs¶

Report bugs for pytest in the issue tracker.

If you are reporting a bug, please include:

Your operating system name and version.
Any details about your local setup that might be helpful in troubleshooting, specifically the Python interpreter version, installed libraries, and pytest version.
Detailed steps to reproduce the bug.

If you can write a demonstration test that currently fails but should pass (xfail), that is a very useful commit to make as well, even if you cannot fix the bug itself.

Fix bugs¶

Look through the GitHub issues for bugs.

Talk to developers to find out how you can fix specific bugs. To indicate that you are going to work on a particular issue, add a comment to that effect on the specific issue.

Don’t forget to check the issue trackers of your favourite plugins, too!

Implement features¶

Look through the GitHub issues for enhancements.

Talk to developers to find out how you can implement specific features.

Write documentation¶

Pytest could always use more documentation. What exactly is needed?

More complementary documentation. Have you perhaps found something unclear?
Documentation translations. We currently have only English.
Docstrings. There can never be too many of them.
Blog posts, articles and such – they’re all very appreciated.

You can also edit documentation files directly in the GitHub web interface, without using a local copy. This can be convenient for small fixes.

Note

Build the documentation locally with the following command:

$ tox -e docs

The built documentation should be available in the doc/en/_build/.

Where ‘en’ refers to the documentation language.

Submitting Plugins to pytest-dev¶

Pytest development of the core, some plugins and support code happens in repositories living under the pytest-dev organisations:

All pytest-dev Contributors team members have write access to all contained repositories. Pytest core and plugins are generally developed using pull requests to respective repositories.

The objectives of the pytest-dev organisation are:

Having a central location for popular pytest plugins
Sharing some of the maintenance responsibility (in case a maintainer no longer wishes to maintain a plugin)

You can submit your plugin by subscribing to the pytest-dev mail list and writing a mail pointing to your existing pytest plugin repository which must have the following:

PyPI presence with a setup.py that contains a license, pytest- prefixed name, version number, authors, short and long description.
a tox.ini for running tests using tox.
a README.txt describing how to use the plugin and on which platforms it runs.
a LICENSE.txt file or equivalent containing the licensing information, with matching info in setup.py.
an issue tracker for bug reports and enhancement requests.
a changelog

If no contributor strongly objects and two agree, the repository can then be transferred to the pytest-dev organisation.

Here’s a rundown of how a repository transfer usually proceeds (using a repository named joedoe/pytest-xyz as example):

joedoe transfers repository ownership to pytest-dev administrator calvin.
calvin creates pytest-xyz-admin and pytest-xyz-developers teams, inviting joedoe to both as maintainer.
calvin transfers repository to pytest-dev and configures team access:
- pytest-xyz-admin admin access;
- pytest-xyz-developers write access;

The pytest-dev/Contributors team has write access to all projects, and every project administrator is in it. We recommend that each plugin has at least three people who have the right to release to PyPI.

Repository owners can rest assured that no pytest-dev administrator will ever make releases of your repository or take ownership in any way, except in rare cases where someone becomes unresponsive after months of contact attempts. As stated, the objective is to share maintenance and avoid “plugin-abandon”.

Creating a pull request¶

Note

See the GitHub Tutorial on pull requests. for an introduction on what pull requests are.

Note

flake8 (enforcing PEP 8) and black are used to ensure a consistent code style.

Fork the pytest GitHub repository. It’s fine to use pytest as your fork repository name because it will live under your user.
Clone your fork locally using git and create a branch:
```
$ git clone git@github.com:YOUR_GITHUB_USERNAME/pytest.git
$ cd pytest
# now, create your own branch off "master":

    $ git checkout -b your-bugfix-branch-name master
```
Given we have “major.minor.micro” version numbers, bug fixes will usually be released in micro releases whereas features will be released in minor releases and incompatible changes in major releases.

If you need some help with Git, follow this quick start guide: https://git.wiki.kernel.org/index.php/QuickStart
Optionally install and enable pre-commit

https://pre-commit.com/ is a framework for managing and maintaining multi-language pre-commit hooks to ensure code-style and code formatting is consistent.

Installing it will run checks whenever you commit, which slows things down however, and might cause conflicts, e.g. between black changing files in a way flake8 does not like them.

Therefore it is usually better to run it via tox -e linting manually, when you are finished with your changes.

$ pip install –user pre-commit $ pre-commit install
Install tox

Tox is used to run the tests in an isolated environment with automatically created virtualenvs:
```
$ pip install tox
```
You can also use a virtualenv directly (see below).
Run all the tests

The following example uses Python 3.7, which needs to be available on your system.

To run all tests and additional linting checks:
```
$ tox -e py37,linting
```
You can now edit your local working copy and run the tests again as necessary.

You can pass different options to tox, and especially the pytest run by tox. For example, to run tests on Python 3.8 and pass options to pytest (e.g. enter pdb on failure) to pytest you can do:
```
$ tox -e py38 -- --pdb
```
Or to only run tests in a particular test module on Python 3.7:
```
$ tox -e py37 -- testing/test_config.py
```
If instead of using tox you prefer to run the tests directly, then you can create a virtual environment and use an editable install with the testing extra:
```
$ python3 -m venv .venv
$ source .venv/bin/activate  # Linux
$ .venv/Scripts/activate.bat  # Windows
$ pip install -e ".[testing]"
```
Afterwards, you can edit the files and run pytest normally:
```
$ pytest testing/test_config.py
```
Create a new changelog entry in the changelog directory. The file should be named <issueid>.<type>.rst, where issueid is the number of the issue (or pull request) related to the change and type is one of bugfix, removal, feature, vendor, doc or trivial, e.g. changelog/2574.bugfix.rst.

You can skip creating a changelog entry if the change doesn’t affect the documented behaviour of Pytest.
Commit and push once your tests pass and you are happy with your change(s):
```
$ git commit -a -m "<commit message>"
$ git push -u
```
Consider adding yourself to the AUTHORS file in alphabetical order, unless your change is trivial.

Finally, submit a pull request through the GitHub website using this data:

head-fork: YOUR_GITHUB_USERNAME/pytest
compare: your-branch-name

base-fork: pytest-dev/pytest
base: master

Writing Tests¶

Writing tests for plugins or for pytest itself is often done using the testdir fixture, as a “black-box” test.

For example, to ensure a simple test passes you can write:

def test_true_assertion(testdir):
    testdir.makepyfile(
        """
        def test_foo():
            assert True
    """
    )
    result = testdir.runpytest()
    result.assert_outcomes(failed=0, passed=1)

Alternatively, it is possible to make checks based on the actual output of the termal using glob-like expressions:

def test_true_assertion(testdir):
    testdir.makepyfile(
        """
        def test_foo():
            assert False
    """
    )
    result = testdir.runpytest()
    result.stdout.fnmatch_lines(["*assert False*", "*1 failed*"])

When choosing a file where to write a new test, take a look at the existing files and see if there’s one file which looks like a good fit. For example, a regression test about a bug in the --lf option should go into test_cacheprovider.py, given that this option is implemented in cacheprovider.py. If in doubt, go ahead and open a PR with your best guess and we can discuss this over the code.

Joining the Development Team¶

Anyone who has successfully seen through a pull request which did not require any extra work from the development team to merge will themselves gain commit access if they so wish (if we forget to ask please send a friendly reminder). This does not mean your workflow to contribute changes, everyone goes through the same pull-request-and-review process and no-one merges their own pull requests unless already approved. It does however mean you can participate in the development process more fully since you can merge pull requests from other contributors yourself after having reviewed them.

Contribution getting started¶

Feature requests and feedback¶

Report bugs¶

Fix bugs¶

Implement features¶

Write documentation¶

Submitting Plugins to pytest-dev¶

Creating a pull request¶

Writing Tests¶

Joining the Development Team¶

Table Of Contents

Related Topics

Useful Links