2290 Merge B08e9e10

Merge Workflow

Merge branches together safely.

Prerequisites

• Git repository initialized
• Branches to merge exist
• Clean working directory recommended

Basic Merge

Standard Merge (with commit)

# Ensure you're on target branch
git checkout main

# Merge source branch
git merge feature/my-feature

This creates a merge commit preserving branch history.

Fast-Forward Merge

# When target hasn't diverged
git merge --ff-only feature/my-feature

This moves the pointer forward without a merge commit.

No Fast-Forward (Force Merge Commit)

# Always create merge commit
git merge --no-ff feature/my-feature

Useful for maintaining clear feature boundaries in history.

Merge Workflow Steps

Step 1: Prepare for Merge

# Check current status
git status

# Ensure working directory is clean
# If not, commit or stash changes

# Switch to target branch
git checkout main

# Update target branch
git pull origin main

Step 2: Preview Merge

# See what will be merged
git log main..feature/branch --oneline

# See file changes
git diff main...feature/branch --stat

# Dry run (check for conflicts without merging)
git merge --no-commit --no-ff feature/branch
git merge --abort  # Cancel preview

Step 3: Execute Merge

# Merge the branch
git merge feature/my-feature -m "Merge feature/my-feature into main"

Step 4: Verify Merge

# Check status
git status

# View merge commit
git log -1

# Verify changes
git diff HEAD~1

Step 5: Push Merged Result

git push origin main

Handling Merge Conflicts

When Conflicts Occur

# Git will report conflicting files
git status

# Files with conflicts shown as:
# both modified: <filename>

Resolve Conflicts

1. Open conflicting files - Look for conflict markers:

   <<<<<<< HEAD
   your changes
   =======
   incoming changes
   >>>>>>> feature/branch
   

2. Edit to resolve - Keep desired code, remove markers

3. Mark as resolved:

   git add <resolved-file>
   

4. Complete merge:

   git commit
   

Abort Merge

# Cancel merge and return to pre-merge state
git merge --abort

Use Merge Tool

# Open configured merge tool
git mergetool

# Common tools: vimdiff, meld, kdiff3, vscode

Merge Strategies

Recursive (Default)

git merge -s recursive feature/branch

Best for most merges, handles renames well.

Ours (Keep Target)

git merge -s ours feature/branch

Keeps all changes from current branch, discards source changes. Use case: Marking a branch as merged without taking changes.

Theirs (Keep Source)

git merge -X theirs feature/branch

Prefers changes from source branch in conflicts.

Octopus (Multi-branch)

git merge branch1 branch2 branch3

Merge multiple branches at once (no conflict resolution).

Squash Merge

Combine all commits into one:

# Squash merge (no commit yet)
git merge --squash feature/branch

# Commit the squashed changes
git commit -m "feat: add feature (squashed)"

Pros: Clean history, single commit Cons: Loses individual commit details

Common Merge Scenarios

Merge Main into Feature (Update Feature)

# On feature branch
git checkout feature/my-feature

# Merge main
git merge main

# Resolve any conflicts
# Push updated feature branch
git push origin feature/my-feature

Merge Feature into Main (Complete Feature)

# On main branch
git checkout main
git pull origin main

# Merge feature
git merge --no-ff feature/my-feature

# Push
git push origin main

# Delete feature branch (optional)
git branch -d feature/my-feature
git push origin --delete feature/my-feature

Merge Release Branch

# Merge to main
git checkout main
git merge --no-ff release/v1.0 -m "Release v1.0"
git tag -a v1.0 -m "Version 1.0"
git push origin main --tags

# Merge back to develop
git checkout develop
git merge --no-ff release/v1.0
git push origin develop

Safety Rules

1. Always update target branch first - Pull before merge
2. Check for uncommitted work - Clean working directory
3. Preview before merging - Know what's coming
4. Don't force push after merge - Others may have pulled
5. Test after merge - Ensure nothing broke
6. Use --no-ff for features - Maintain clear history

Error Handling

Merge Conflict

CONFLICT (content): Merge conflict in <file>
Automatic merge failed.

Resolution:
1. Edit conflicting files
2. git add <resolved-files>
3. git commit

Cannot Fast-Forward

Error: Not possible to fast-forward.

Options:
1. Allow merge commit: git merge <branch>
2. Rebase instead: git rebase <branch>
3. Force FF (loses commits): Not recommended

Nothing to Merge

Already up to date.

The branches are identical - no merge needed.