Please read the Code of Conduct which explains the minimum behavior expectations for Nelson contributors.
When opening issues or commenting on existing issues, please make sure discussions are related to concrete technical issues with Nelson.
This section will guide you through the contribution process.
Fork the project on GitHub and clone your fork locally.
For developing new features and bug fixes, the master
branch should be pulled
and built upon.
Create a branch and start hacking:
$ git checkout -b my-branch -t origin/master
Make sure git knows your name and email address:
$ git config --global user.name "J. Random User"
$ git config --global user.email "[email protected]"
Add and commit:
$ git add my/changed/files
$ git commit
The commit message should describe what changed and why.
-
The first line should:
- contain a short description of the change
- be 50 characters or less
- be entirely in lowercase with the exception of proper nouns, acronyms, and the words that refer to code, like function/variable names
- be prefixed with the name of the changed subsystem and start with an
imperative verb. Check the output of
git log --oneline files/you/changed
to find out what subsystems your changes touch.
-
Keep the second line blank.
-
Wrap all other lines at 72 columns.
-
If your patch fixes an open issue, you can add a reference to it at the end of the log. Use the
Fixes:
prefix and the full issue URL. For other references useRefs:
.
Use git rebase
(not git merge
) to synchronize your work with the main
repository.
$ git fetch upstream
$ git rebase upstream/master
Bug fixes and features should come with tests. Looking at other tests to see how they should be structured can also help.
(See the DEVELOPMENT.md for more details.)
$ git push origin my-branch
Pull requests are usually reviewed within a few days.
You will probably get feedback or requests for changes to your Pull Request. This is a big part of the submission process so don't be discouraged!
To make changes to an existing Pull Request, make the changes to your branch. When you push that branch to your fork, GitHub will automatically update the Pull Request.
You can push more commits to your branch:
$ git add my/changed/files
$ git commit
$ git push origin my-branch
Or you can rebase against master:
$ git fetch --all
$ git rebase origin/master
$ git push --force-with-lease origin my-branch
Or you can amend the last commit (for example if you want to change the commit log).
$ git add any/changed/files
$ git commit --amend
$ git push --force-with-lease origin my-branch
Important: The git push --force-with-lease
command is one of the few ways
to delete history in git. Before you use it, make sure you understand the risks.
Feel free to post a comment in the Pull Request to ping reviewers if you are awaiting an answer on something. If you encounter words or acronyms that seem unfamiliar.
Note that multiple commits often get squashed when they are landed (see the notes about commit squashing).
In order to land, a Pull Request needs to be reviewed and approved by at least one Nelson Collaborator and pass a CI (Continuous Integration) test run. After that, as long as there are no objections from a Collaborator, the Pull Request can be merged. If you find your Pull Request waiting longer than you expect, see the notes about the waiting time.
When a collaborator lands your Pull Request, they will post
a comment to the Pull Request page mentioning the commit(s) it
landed as. GitHub often shows the Pull Request as Closed
at this
point, but don't worry. If you look at the branch you raised your
Pull Request against (probably master
), you should see a commit with
your name on it. Congratulations and thanks for your contribution!
When the commits in your Pull Request land, they will be squashed into one commit per logical change. Metadata will be added to the commit message (including links to the Pull Request, links to relevant issues, and the names of the reviewers). The commit history of your Pull Request, however, will stay intact on the Pull Request page.
A Pull Request is approved either by saying LGTM, which stands for "Looks Good To Me", or by using GitHub's Approve button. GitHub's Pull Request review feature can be used during the process.
After you push new changes to your branch, you need to get approval for these new changes again, even if GitHub shows "Approved" because the reviewers have hit the buttons before.
Every Pull Request needs to be tested to make sure that it works on the platforms that Nelson supports. This is done by running the code through the CI system.
Only a Collaborator can start a CI run. Usually one of them will do it for you as approvals for the Pull Request come in. If not, you can ask a Collaborator to start a CI run.
A Pull Request needs to stay open for at least 48 hours (72 hours on a weekend) from when it is submitted, even after it gets approved and passes the CI. This is to make sure that everyone has a chance to weigh in. If the changes are trivial, collaborators may decide it doesn't need to wait. A Pull Request may well take longer to be merged in.
By making a contribution to this project, I certify that:
-
(a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or
-
(b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or
-
(c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it.
-
(d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.
-
(e) As contributor, you must agree a Contributor Licensing Agreement. This CLA allows to main author(s) to re-licensing Nelson (GPLv3, LGPL, ...) without need to ask all others contributors.