Git Merge Commands

Overview

The git merge command is used to integrate changes from one branch into another. It combines the changes made in different branches and helps in synchronizing work. This document covers the basic and advanced usage of git merge.

Basic Merge

git merge <branch>

Merges the specified branch into the current branch.

git merge <branch>

Example

git checkout main
git merge feature-branch

This command merges changes from feature-branch into the main branch.

Merge with Fast-Forward

git merge --ff <branch>

Performs a fast-forward merge if possible. This is the default behavior when the current branch is a direct ancestor of the branch being merged.

git merge --ff <branch>

Example

git checkout main
git merge --ff feature-branch

This command performs a fast-forward merge if main is a direct ancestor of feature-branch.

Merge with No Fast-Forward

git merge --no-ff <branch>

Performs a merge with a merge commit, even if a fast-forward merge is possible. This is useful for preserving the history of the branch being merged.

git merge --no-ff <branch>

Example

git checkout main
git merge --no-ff feature-branch

This command creates a merge commit even if the feature-branch can be fast-forwarded into main.

Merge with Commit Message

git merge --no-commit <branch>

Merges the specified branch into the current branch but does not automatically create a commit. This allows you to review changes before committing.

git merge --no-commit <branch>

Example

git checkout main
git merge --no-commit feature-branch

This command merges feature-branch into main without committing the merge, allowing you to review and modify changes before committing.

Merge with Strategy

git merge -s <strategy> <branch>

Uses a specific merge strategy to combine changes. Common strategies include recursive, ours, and theirs.

git merge -s <strategy> <branch>

Example

git checkout main
git merge -s ours feature-branch

This command uses the ours strategy to merge feature-branch into main, favoring the current branch's changes.

Merge with Message

git merge -m "<message>" <branch>

Merges the specified branch and includes a custom commit message for the merge commit.

git merge -m "<message>" <branch>

Example

git checkout main
git merge -m "Merge feature-branch into main" feature-branch

This command merges feature-branch into main with the specified commit message.

Resolve Merge Conflicts

Handling Conflicts

If conflicts arise during a merge, Git will pause the merge process and mark the conflicting files. You need to manually resolve these conflicts and then complete the merge.

Example

git merge feature-branch
# Resolve conflicts in the files
git add <resolved-file>
git commit

This process involves resolving conflicts in files marked by Git, staging the resolved files, and then committing the merge.

Summary

The git merge command is a key tool for integrating changes from one branch into another. It provides options for fast-forward merges, preserving history, and using specific merge strategies. Handling merge conflicts is a common part of the merging process, requiring manual resolution before finalizing the merge. For more detailed information on each command, refer to the official Git documentation.