Git and GitHub

This document describes some tips and tricks for using Git and GitHub. There are also some best practices for Git and GitHub.

Rebasing Commits

While projects vary in their opinions on whether merge commits should be avoided or not, it is generally a good idea to rebase a feature branch before submitting a pull request.

Rebasing allows you to alter a series of commits, changing the history of your repository. Typically you rebase a branch to:

  • Combine smaller commits made during development into larger, logical commits that are easier to understand and review, or split up larger commits into smaller commits for the same purpose.
  • Alter commit messages of previous commits.
  • Move a branch to be based on the latest commit of the branch you want to merge into and resolve any conflicts that occur.

These changes all make the code review process as well as the merging process easier, and are recommended for all pull requests.


Rebasing code that has already been pushed to a public or shared repository makes it very difficult for others to update their local repositories. Only rebase branches that you are absolutely sure no one else is using, such as feature branches on your personal fork.

See also

Using Git rebase
A short guide on how to use the git rebase command.

Asking for Review

When asking someone for a code review, it is recommended to add a new comment to a pull request using the @Username syntax. This notifies them via email that a review has been requested. Adding the @Username to the pull request description will not send out the notification and thus isn’t recommended.

You may also add an attachment to a bug in Bugzilla and paste in the URL for the pull request as the content. This will cause Bugzilla to link to the pull request and allow you to set the review bit on the attachment to track the state of the review in Bugzilla.

Owners and the Mozilla GitHub Organization

See the GitHub page on for information on the Mozilla organization on GitHub or anything that requires owner access for the organization.