Contributing

Welcome to cg635-clock-generator contributor’s guide.

This document focuses on getting any potential contributor familiarized with the development processes, but other kinds of contributions are also appreciated.

If you are new to using git or have never collaborated in a project previously, please have a look at contribution-guide.org. Other resources are also listed in the excellent guide created by FreeCodeCamp[1].

Please notice, all users and contributors are expected to be open, considerate, reasonable, and respectful. When in doubt, Python Software Foundation’s Code of Conduct is a good reference in terms of behavior guidelines.

Issue Reports

If you experience bugs or general issues with cg635-clock-generator, please have a look on the issue tracker. If you don’t see anything useful there, please feel free to fire an issue report.

Please don’t forget to include the closed issues in your search. Sometimes a solution was already reported, and the problem is considered solved.

New issue reports should include information about your programming environment (e.g., operating system, Python version) and steps to reproduce the problem. Please try also to simplify the reproduction steps to a very minimal example that still illustrates the problem you are facing. By removing other factors, you help us to identify the root cause of the issue.

Documentation Improvements

You can help improve cg635-clock-generator docs by making them more readable and coherent, or by adding missing information and correcting mistakes.

cg635-clock-generator documentation uses Sphinx as its main documentation compiler. This means that the docs are kept in the same repository as the project code, and that any documentation update is done in the same way was a code contribution.

We are using CommonMark format.

When working on documentation changes in your local machine, you can compile them using tox:

$ tox -e docs

and use Python’s built-in web server for a preview in your web browser (http://localhost:8000):

$ python3 -m http.server --directory 'docs/_build/html'

Code Contributions

Submit an issue

Before you work on any non-trivial code contribution it’s best to first create a report in the issue tracker to start a discussion on the subject. This often provides additional considerations and avoids unnecessary work.

Create an environment

Before you start coding, we recommend creating an isolated virtual environment to avoid any problems with your installed Python packages. This can easily be done via venv:

$ python3 -m venv <PATH TO VENV>
$ source <PATH TO VENV>/bin/activate

Clone the repository

  1. Clone this copy to your local disk:

    $ git clone git@gitlab.desy.de:leandro.lanzieri/cg635-clock-generator.git
$ cd cg635-clock-generator

  2. You should run:

    $ pip install -U pip setuptools -e .

    to be able to import the package under development in the Python REPL.

  3. Install pre-commit_:

    $ pip install pre-commit
$ pre-commit install

    cg635-clock-generator comes with a lot of hooks configured to automatically help the developer to check the code being written.

Implement your changes

  1. Create a branch to hold your changes (for this you need an account on gitlab.desy.de and developer rights):

    $ git checkout -b my-feature

    and start making changes. Never work on the main branch!

  2. Start your work on this branch. Don’t forget to add docstrings to new functions, modules and classes, especially if they are part of public APIs.

  3. Add yourself to the list of contributors in AUTHORS.md.

  4. When you’re done editing, record your changes in git by running:

    $ git add <MODIFIED FILES>
$ git commit

    Please make sure to see the validation messages from pre-commit_ and fix any eventual issues. This should automatically use flake8/black to check/fix the code style in a way that is compatible with the project.

    Important: Don’t forget to add unit tests and documentation in case your contribution adds an additional feature and is not just a bugfix.

    Moreover, writing a descriptive commit message is highly recommended. In case of doubt, you can check the commit history with:

    $ git log --graph --decorate --pretty=oneline --abbrev-commit --all

    to look for recurring communication patterns.

  5. Please check that your changes don’t break any unit tests with:

    $ tox

    (after having installed tox_ with pip install tox or pipx).

    You can also use tox_ to run several other pre-configured tasks in the repository. Try tox -av to see a list of the available checks.

Submit your contribution

  1. If everything works fine, push your local branch to GitHub with:

    $ git push -u origin my-feature

  2. Go to the web page of your fork and click “Create merge request” to send your changes for review.

Troubleshooting

The following tips can be used when facing problems to build or test the package:

  1. Make sure to fetch all the tags from the upstream repository. The command git describe --abbrev=0 --tags should return the version you are expecting. If you are trying to run CI scripts in a fork repository, make sure to push all the tags. You can also try to remove all the egg files or the complete egg folder, i.e., .eggs, as well as the *.egg-info folders in the src folder or potentially in the root of your project.

  2. Sometimes tox_ misses out when new dependencies are added, especially to setup.cfg and docs/requirements.txt. If you find any problems with missing dependencies when running a command with tox_, try to recreate the tox environment using the -r flag. For example, instead of:

    tox -e docs

    Try running:

    tox -r -e docs

  3. Make sure to have a reliable tox_ installation that uses the correct Python version (e.g., 3.8+). When in doubt you can run:

    tox --version
## OR
which tox

    If you have trouble and are seeing weird errors upon running tox_, you can also try to create a dedicated virtual environment with a tox_ binary freshly installed. For example:

    python3 -m venv .venv
source .venv/bin/activate
.venv/bin/pip install tox
.venv/bin/tox -e all

  4. Pytest can drop you in an interactive session in the case an error occurs. In order to do that you need to pass a --pdb option (for example by running tox -- -k <NAME OF THE FALLING TEST> --pdb). You can also setup breakpoints manually instead of using the --pdb option.