Fork and Clone the SkyPy Repository¶
You should only need to do this step once
First fork the SkyPy repository. A fork is your own remote copy of the repository on GitHub. To create a fork:
Go to the SkyPy GitHub Repository
Click the Fork button (in the top-right-hand corner)
Choose where to create the fork, typically your personal GitHub account
Next clone your fork. Cloning creates a local copy of the repository on your computer to work with. To clone your fork:
git clone https://github.com/<your-account>/skypy.git
Finally add the
skypyproject repository as a remote. This will allow you to fetch changes made to the codebase. To add the
git remote add skypyproject https://github.com/skypyproject/skypy.git
Create a branch for your new feature¶
Create a branch off the
skypyproject main branch. Working on unique branches for each new feature simplifies the development, review and merge processes by maintining logical separation. To create a feature branch:
git fetch skypyproject
git checkout -b <your-branch-name> skypyproject/main
Write the new code you would like to contribute and commit it to the feature branch on your local repository. Ideally commit small units of work often with clear and descriptive commit messages describing the changes you made. To commit changes to a file:
git add file_containing_your_contribution
git commit -m 'Your clear and descriptive commit message'
Push the contributions in your feature branch to your remote fork on GitHub:
git push origin <your-branch-name>
Note: The first time you push a feature branch you will probably need to use
--set-upstream origin to link to your remote fork:
git push --set-upstream origin <your-branch-name>
Open a Pull Request¶
When you feel that work on your new feature is complete, you should create a Pull Request. This will propose your work to be merged into the main SkyPy repository.
Go to SkyPy Pull Requests
Click the green New pull request button
Click compare across forks
Confirm that the base fork is
skypyproject/skypyand the base branch is
Confirm the head fork is
<your-account>/skypyand the compare branch is
Give your pull request a title and fill out the the template for the description
Click the green Create pull request button
A series of automated checks will be run on your pull request, some of which will be required to pass before it can be merged into the main codebase:
Tests(Required) runs the unit tests in four predefined environments;
latest supported versions,
oldest supported versions,
macOS latest supportedand
Windows latest supported. Click “Details” to view the output including any failures.
codecovreports the test coverage for your pull request; you should aim for
codecov/patch — 100.00%. Click “Details” to view coverage data.
Updating your branch¶
As you work on your feature, new commits might be made to the
skypyproject main branch. You will need to update your branch with these new commits before your pull request can be accepted. You can achieve this in a few different ways:
If your pull request has no conflicts, click Update branch
If your pull request has conflicts, click Resolve conflicts, manually resolve the conflicts and click Mark as resolved
skypyprojectmain branch from the command line:git fetch skypyproject git merge skypyproject/main
rebase your feature branch onto the
skypyprojectmain branch from the command line:git fetch skypyproject git rebase skypyproject/main
Warning: It is bad practice to rebase commits that have already been pushed to a remote such as your fork. Rebasing creates new copies of your commits that can cause the local and remote branches to diverge.
git push --force will overwrite the remote branch with your newly rebased local branch. This is strongly discouraged, particularly when working on a shared branch where you could erase a collaborators commits.
More information regarding the usage of GitHub can be found in the GitHub Guides.
Before your pull request can be merged into the codebase, it will be reviewed by one of the SkyPy developers and required to pass a number of automated checks. Below are a minimum set of guidelines for developers to follow:
For more information see the Astropy Coding Guidelines.
Pull requests will require existing unit tests to pass before they can be merged. Additionally, new unit tests should be written for all new public methods and functions. Unit tests for each submodule are contained in subdirectories called
tests and you can run them locally using
pytest. For more information see the Astropy Testing Guidelines.
If your unit tests check the statistical distribution of a random sample, the test outcome itself is a random variable, and the test will fail from time to time. Please mark such tests with the
@pytest.mark.flaky decorator, so that they will be automatically tried again on failure. To prevent non-random test failures from being run multiple times, please isolate random statistical tests and deterministic tests in their own test cases.
All public classes, methods and functions require docstrings. You can build documentation locally by installing sphinx-astropy and calling
make html in the
docs subdirectory. Docstrings should include the following sections:
For more information see the Astropy guide to Writing Documentation.