Rebasing Commits in Git

Tutorial 3 of 5

1. Introduction

1.1 Tutorial Goal

This tutorial aims to provide a thorough understanding of the concept of rebasing in Git, a powerful tool that can help keep your commit history clean and understandable.

1.2 Learning Outcomes

By the end of this tutorial, you will understand how to:
- Understand the concept of git rebasing
- Use the git rebase command
- Resolve merge conflicts during rebasing

1.3 Prerequisites

  • Basic knowledge of Git and GitHub.
  • Git installed on your local machine.

2. Step-by-Step Guide

2.1 Git Rebasing

Rebasing in Git is a process to reapply commits on top of another base tip. This is a great way to integrate changes from one branch into another. It provides an alternative to merging.

When you rebase, Git finds the base of your branch, finds all the commits between that base and HEAD, and re-applies them to the current branch one by one.

2.2 Best Practices

  • Avoid rebase of the public branch: Once pushed and shared, avoid using the rebase command on public branches.
  • Use rebase for local branch cleanup: You can make your feature branch up to date with the latest code from the master branch.

3. Code Examples

3.1 Basic Rebasing

Here's an example of how to rebase your feature branch from the master branch.

# switch to the master branch
git checkout master

# pull the latest changes
git pull

# switch to your feature branch
git checkout feature_branch

# rebase your feature branch from master
git rebase master

3.2 Resolving Conflicts

In case of conflicts, Git will pause and allow you to resolve those conflicts before continuing the rebase process. Here's how to resolve conflicts.

# when conflict occurs, git will pause rebase and give you a chance to resolve it

# after resolving conflicts, add them to the staging area
git add .

# continue the rebase process
git rebase --continue

# if you want to abort the rebase process
git rebase --abort

4. Summary

In this tutorial, we've covered the concept of rebasing in Git, the working mechanism of git rebase, and how to resolve conflicts during rebasing. The next step is to practice these concepts with different examples and scenarios.

5. Practice Exercises

5.1 Exercise 1

Create a new branch, make some commits, and then rebase it onto the master branch.

5.2 Exercise 2

Create a scenario where a rebase would cause a merge conflict. Resolve this conflict.

Solutions

Solution to Exercise 1

# create a new branch
git checkout -b new_branch

# make some commits
echo "Some text" > file.txt
git add file.txt
git commit -m "Add file.txt"

# rebase onto master
git checkout master
git pull
git checkout new_branch
git rebase master

Solution to Exercise 2

# create a new branch
git checkout -b conflict_branch

# make a commit
echo "Text A" > conflict.txt
git add conflict.txt
git commit -m "Add conflict.txt"

# switch to master, make a conflicting commit
git checkout master
echo "Text B" > conflict.txt
git add conflict.txt
git commit -m "Add conflicting conflict.txt"

# rebase conflict_branch onto master, resolve conflict
git checkout conflict_branch
git rebase master
# At this point, a conflict will occur. Edit conflict.txt to resolve it, then:
git add conflict.txt
git rebase --continue

For further practice, try varying the order and content of commits to produce different kinds of conflicts.