Rebasing

Time to rewrite history

Overview

Why rewrite history?

• Git is not only a source control tool, it is also a communication tool
  • Order of commits, logical grouping, good commit messages help to communicate changes
  • Think of the person reviewing your PRs as a potential axe-murderer. Axe murderers hate fix-up commits.
• Golden rule: Never rewrite history on shared/public branches

Visualise

Rebasing and Merging are two methods that achieve the same goal - the integration of changes from one branch into another branch

Prerequisites

• Git (2.x)
• (Optional) hub - https://github.com/github/hub
• Fork the repository from https://github.com/feedhenry/git-tutorial

# Clone the forked repository
git clone git@github.com:<github_username>/git-tutorial.git

Practical

cd git-tutorial # From earlier
git fetch
git checkout rebase

# The rebase branch was branched from master a while ago
# It's out of date (master has moved on)
# And there's bad commits in our history that we're going to fixup
git log --pretty=oneline

# First, lets interactively rebase our last 4 commits
git rebase -i HEAD~4 # Note the lack of a branch

# Fix up the commits - think about re-ordering or (s)quashing
# the version bumps and (r)eword the commit messages.
# Also, delete commits that are of no value
git rebase origin/master

# Alternatively:
# We can do both a history rewrite and a rebase via:
git rebase -i origin/master