Contributing to Open-Source with Github
9 November 2011
You want to contribute to an open-source project, but are scared away by all the git-complexity involved? This small guide will help you out.
Step 1 - Fork, fork, fork
First create a fork of the original project. You can do this easily by clicking the “Fork” button on the top of the Github project page. This will give you your own copy (fork) of the entire repository.
Then, check out your fork:
git clone firstname.lastname@example.org:ariejan/repo-name.git
Step 2 - Contribute
Before you start writing code there are a few tasks you need to perform:
- Are there tests for this project? Are they all green? If not, fix this first. (using this same step, of course)
- Create a new branch:
git checkout -b fix_for_this_or_that
- Red-Green-Refactor (e.g. write code)
- Commit your changes (in your
Step 3 - Sharing your contribution
With your contribution done, don’t merge it back into
master is your way of receiving changes from the original (upstream) repo (see step 4).
First push your branch to Github, so you can share it with others.
git push origin fix_for_this_or_that
You should now see this branch in your Github project page. You’ll also notice there’s a “Pull Request” button at the top. Click it if you want the project maintainer to pull your
fix_for_this_or_that branch into the main project.
Step 4 - Keeping up-to-date
Over time the
master of your fork will start lagging behind. Because you did not merge any of your code changes into the
master of your fork, you can update it easily.
Before you can pull in changes you must add a git remote for it. You can use the Git Read-only URL for this.
git remote add upstream https://github.com/some_one/some-repo.git
Now, for raking in the changes;
git checkout master git fetch upstream git merge upstream/master
Step 4.5 - Keeping your feature branch up-to-date
If you pulled in changes from
upstream and did not yet share your feature branch, you can rebase your feature branch. This makes sure you have the latest code from
master. This also makes merging your pull request easier.
Do not rebase if you already pushed your branch to Github. Read why.
git checkout fix_for_this_or_that git rebase master
If any conflict arise, fix them. And continue your rebase:
git add conflicting_file git rebase --continue
You may also abort the rebase:
git rebase --abort
This small guide will help you to fork repositories on Github and use them to contribute code. By using the approach you lighten the task of the project maintainer who can easily checkout your specific changes and decide to include them into the main project or not.