Rebase

Rebasing is a powerful feature in Git that allows you to integrate changes from one branch into another. This document explains how to rebase and provides visual diagrams to illustrate the process.

What is Rebase?

Rebasing involves moving or combining a sequence of commits to a new base commit. This results in a linear project history and can help simplify merge conflicts.

How Rebase Works

When you rebase a branch onto another, Git replays the commits from your current branch on top of the specified branch.

graph TD;
    A[Commit A]:::commit --> B[Commit B]:::commit
    B --> C[Commit C]:::commit
    D[Master Branch]:::branch --> E[Commit D]:::commit
    E --> F[Commit E]:::commit

    B --> G[Rebase onto Master]:::action
    G --> F[New Commit C']:::commit

    classDef commit fill:#90ee90, stroke:#000, stroke-width:2px;
    classDef branch fill:#f08080, stroke:#000, stroke-width:2px;
    classDef action fill:#ffcc00, stroke:#000, stroke-width:2px;

    linkStyle 0 stroke:#2ca02c,stroke-width:2px
    linkStyle 1 stroke:#2ca02c,stroke-width:2px
    linkStyle 2 stroke:#2ca02c,stroke-width:2px
    linkStyle 3 stroke:#2ca02c,stroke-width:2px
    linkStyle 4 stroke:#ff4500,stroke-width:2px

Example Rebase

Assume you have a feature branch dev based on master. The commits look like this:

graph TD;
    M[Master]:::branch --> A[Commit A]:::commit
    A --> B[Commit B]:::commit
    M --> C[Commit C]:::commit

    classDef commit fill:#90ee90, stroke:#000, stroke-width:2px;
    classDef branch fill:#f08080, stroke:#000, stroke-width:2px;

    linkStyle 0 stroke:#2ca02c,stroke-width:2px
    linkStyle 1 stroke:#2ca02c,stroke-width:2px
    linkStyle 2 stroke:#2ca02c,stroke-width:2px

If you want to rebase your dev branch onto master, after running git rebase master, the history would look like:

graph TD;
    M[Master]:::branch --> A[Commit A]:::commit
    A --> B[Commit B]:::commit
    C[Commit C]:::commit
    B --> D[New Commit C']:::commit

    classDef commit fill:#90ee90, stroke:#000, stroke-width:2px;
    classDef branch fill:#f08080, stroke:#000, stroke-width:2px;

    linkStyle 0 stroke:#2ca02c,stroke-width:2px
    linkStyle 1 stroke:#2ca02c,stroke-width:2px
    linkStyle 2 stroke:#2ca02c,stroke-width:2px

Commands

To perform a rebase:

# Start rebasing onto another branch
git rebase <branch>

For example:

# Rebase dev branch onto master
git rebase master

To continue the rebase after resolving conflicts:

git rebase --continue

To abort the rebase process:

git rebase --abort

Handling Conflicts

During rebasing, if you encounter conflicts, you'll need to resolve them manually. Once you've fixed the conflicts, use the commands above to continue or abort the rebase.

Summary

Rebase: Moves or combines commits to a new base commit for a linear history.
Commands: git rebase <branch>, git rebase --continue, git rebase --abort.
Conflict Resolution: Similar to merging, requires manual intervention in case of conflicts.

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