How to modify commits during rebase

Introduction

Git rebase is a powerful technique that allows developers to modify commit history and streamline project workflows. This tutorial explores interactive commit editing strategies, providing developers with essential skills to manipulate and refine their Git repository's commit sequence effectively.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL git(("Git")) -.-> git/BasicOperationsGroup(["Basic Operations"]) git(("Git")) -.-> git/BranchManagementGroup(["Branch Management"]) git/BasicOperationsGroup -.-> git/commit("Create Commit") git/BranchManagementGroup -.-> git/branch("Handle Branches") git/BranchManagementGroup -.-> git/log("Show Commits") git/BranchManagementGroup -.-> git/cherry_pick("Cherry Pick") git/BranchManagementGroup -.-> git/rebase("Reapply Commits") subgraph Lab Skills git/commit -.-> lab-452173{{"How to modify commits during rebase"}} git/branch -.-> lab-452173{{"How to modify commits during rebase"}} git/log -.-> lab-452173{{"How to modify commits during rebase"}} git/cherry_pick -.-> lab-452173{{"How to modify commits during rebase"}} git/rebase -.-> lab-452173{{"How to modify commits during rebase"}} end

Git Rebase Basics

What is Git Rebase?

Git rebase is a powerful technique used to modify the base of a branch, effectively reorganizing commit history. Unlike merging, which creates a new merge commit, rebasing rewrites the project history by creating new commits for each commit in the original branch.

Basic Rebase Workflow

## Basic rebase command
git checkout feature-branch
git rebase main

Types of Rebase

Simple Linear Rebase

graph LR A[Main Branch] --> B[Commit 1] B --> C[Commit 2] C --> D[Commit 3] E[Feature Branch] --> F[Feature Commit 1] F --> G[Feature Commit 2]

Interactive Rebase

Interactive rebase allows more granular control over commit history:

## Start interactive rebase
git rebase -i HEAD~3

Key Rebase Commands

Command	Description	Usage
pick	Use commit as-is	Default action
reword	Modify commit message	Change commit description
edit	Stop and modify commit	Alter commit contents
squash	Combine commits	Merge multiple commits
drop	Remove commit	Delete specific commits

When to Use Rebase

Cleaning up local branch history
Incorporating latest changes from main branch
Preparing code for code review
Maintaining a clean, linear project history

Potential Risks

Rewriting shared history can cause conflicts
Should not be used on public/shared branches
Requires careful handling to avoid losing work

Best Practices

Always backup your branch before rebasing
Use interactive rebase for complex history modifications
Communicate with team when modifying shared branches

By understanding Git rebase, developers can maintain a cleaner, more organized project history with LabEx's advanced version control techniques.

Interactive Commit Editing

Understanding Interactive Rebase

Interactive rebase provides developers with powerful tools to modify commit history precisely and efficiently. It allows you to edit, squash, reorder, or drop commits before finalizing your branch.

Starting Interactive Rebase

## Interactive rebase for last 3 commits
git rebase -i HEAD~3

Interactive Rebase Commands

Command	Action	Description
pick	Keep commit	Default action, uses commit as-is
reword	Modify message	Change commit description
edit	Stop and modify	Alter commit contents
squash	Combine commits	Merge multiple commits
drop	Remove commit	Delete specific commits

Practical Editing Scenarios

1. Modifying Commit Messages

## Start interactive rebase
git rebase -i HEAD~3

## Change 'pick' to 'reword' for desired commits
## Save and exit editor
## Modify commit messages when prompted

2. Squashing Commits

graph LR A[Original Commits] --> B[Commit 1] B --> C[Commit 2] C --> D[Commit 3] E[After Squash] --> F[Combined Commit]

3. Splitting Commits

## Use 'edit' mode to break a commit into multiple commits
git rebase -i HEAD~3
## Mark commit for editing
git reset HEAD~
git add specific_files
git commit
git rebase --continue

Advanced Editing Techniques

Reordering Commits

Simply rearrange lines in interactive rebase editor
Useful for organizing logical commit sequence

Dropping Unnecessary Commits

Remove commits that don't add value
Helps maintain clean, meaningful project history

Common Pitfalls

Issue	Solution
Modifying shared branches	Avoid rebasing public branches
Losing work	Always create backup before complex rebase
Merge conflicts	Resolve conflicts carefully

LabEx Pro Tips

Use interactive rebase to clean up local branch history
Practice in a safe environment before applying to main projects
Communicate with team about history modifications

Example Workflow

## Typical interactive rebase workflow
git checkout feature-branch
git rebase -i main
## Edit commits as needed
git push --force-with-lease

By mastering interactive commit editing, developers can create more meaningful, organized commit histories with precision and control.

Rebase Best Practices

Fundamental Guidelines

1. Local Branch Rebase Only

Never rebase shared or public branches
Limit rebase to personal feature branches

## Safe rebase workflow
git checkout feature-branch
git rebase main

2. Always Create Backups

## Create a backup branch before complex rebase
git branch feature-branch-backup
git rebase -i HEAD~3

Commit History Management

Maintaining Clean History

graph LR A[Messy Commits] --> B[Organized Commits] B --> C[Linear History]

Squashing Commits

Scenario	Recommendation
Multiple WIP commits	Squash before merging
Redundant changes	Combine similar commits

Conflict Resolution Strategies

Handling Merge Conflicts

## Interactive conflict resolution
git rebase main
## Resolve conflicts manually
git add resolved_files
git rebase --continue

Advanced Rebase Techniques

Using --force-with-lease

## Safer force push
git push --force-with-lease origin feature-branch

Common Anti-Patterns

Anti-Pattern	Consequence	Solution
Rebasing shared branches	History destruction	Avoid rebasing
Frequent rebases	Unstable history	Limit to necessary cases
Ignoring conflicts	Broken code	Carefully resolve conflicts

LabEx Recommended Workflow

Work on local feature branch
Keep branch updated with main
Clean up commits before merging
Use interactive rebase

Example Workflow

## Recommended rebase workflow
git checkout feature-branch
git pull origin main
git rebase -i main
git push --force-with-lease

Performance Considerations

Rebase Performance Tips

Use shallow rebases
Avoid rebasing large histories
Break complex rebases into smaller steps

Error Handling

Common Rebase Errors

## Abort problematic rebase

## Recover from failed rebase

Final Recommendations

Communicate with team about history changes
Practice rebase in safe environments
Use version control thoughtfully
Prioritize code quality over complex history manipulation

By following these best practices, developers can effectively use Git rebase to maintain clean, organized project histories with LabEx's advanced version control techniques.

Summary

By mastering Git rebase techniques, developers can clean up commit history, merge related changes, and maintain a more organized and readable version control workflow. Understanding interactive commit editing empowers programmers to create cleaner, more focused commit sequences that enhance project collaboration and code quality.