Editing PRs as a maintainer

GitHub has this really neat feature, where contributors to a project can allow maintainers of the project to push to those branches in their forks for which a PR was submitted.

Unfortunately the UI doesn’t really give any hint for maintainers whether they can do this, and the instructions from GitHub on how to do this, are a little bit bloated, in the sense that it requires you to clone the fork.

But there is an easier way—not requiring a whole clone of the repo and 11 steps to complete—to do this within your own local copy of the code, using git commands. The only challenge being, that you have to use git in a slightly different way than usual.

So here it is, how it will work:

0. First: make sure your local copy of the repository is up to date with the upstream.

1. Fetch the branch you want to edit to a local branch:

    $ git fetch git@github.com:shreyaspapi/packit.git \
        +issue701:shreyaspapi-packit-issue701

2. Checkout and modify the local branch. In this case rebase it to master:

    $ git checkout shreyaspapi-packit-issue701
    $ git rebase master

3. Push the change back to the original branch. This is where you’ll find out if you actually have the permissions to do it :)

    $ git push --force-with-lease git@github.com:shreyaspapi/packit.git \
        +shreyaspapi-packit-issue701:issue701

While reading through the man pages in order to figure out how to do the above, I’ve learnt how <refspec> works. That’s the thing at the end of the fetch and push commands above, and this is its syntax:

    +<src>:<dest>

In the case of fetch, I’ve used <refspec> to specify which remote branch to fetch to which local branch. In the case of push, the other way around: which local branch to push to which remote branch.

I do realize that there are many more ways for doing this—that’s the beauty of git, I guess :) I will probably stick to using the commands above, because I find them explicit (less likely to make a mistake) and easy to remember.