Sync Branch

Merge one branch into another, handling conflicts and preserving work in progress.

Preferences

_Read ~/.claude/skills/sync-branch/preferences.md using the Read tool. If not found, no preferences are set._

Context

_On startup, use Bash to detect: current git branch, git status, and remote URL (git remote get-url origin). Skip any that fail._

Command routing

Check $ARGUMENTS:

• `help` → display help then stop
• `config` → interactive setup then stop
• `reset` → delete ~/.claude/skills/sync-branch/preferences.md, confirm, stop
• anything else → sync branches

Flags

Parse from $ARGUMENTS:

• `--no-push` — merge locally, don't push
• `--dry-run` — show what would happen without executing
• Positional args: $0 = source branch, $1 = target branch

Help

Sync Branch — Merge one branch into another

Usage:
  /sync-branch                          Merge default source into current branch
  /sync-branch <source>                 Merge source into current branch
  /sync-branch <source> <target>        Merge source into target
  /sync-branch --no-push <source>       Merge without pushing
  /sync-branch --dry-run <source>       Preview without executing
  /sync-branch config                   Set defaults
  /sync-branch reset                    Clear preferences
  /sync-branch help                     This help

Examples:
  /sync-branch main
  /sync-branch main all-demos
  /sync-branch --dry-run main feature/auth
  /sync-branch --no-push develop

How it works:
  1. Stashes uncommitted work (if any)
  2. Updates source and target branches from remote
  3. Merges source into target
  4. Resolves conflicts (preserving both sides)
  5. Pushes target (unless --no-push)
  6. Restores original branch and stash

Current preferences:
  (shown above under Preferences)

Config

Use `AskUserQuestion`:

Q1 — "Default source branch?" (main (default), develop, custom) Q2 — "Auto-push after merge?" (Yes (default), No) Q3 — "Conflict resolution style?" (preserve-both (default) — keep changes from both sides, ask-each — show each conflict and ask, prefer-source — favor source branch, prefer-target — favor target branch)

Save to ~/.claude/skills/sync-branch/preferences.md.

First-time detection

If no preferences file exists, show: "First time using /sync-branch? Run /sync-branch config to set defaults, or continue — I'll merge main into your current branch."

Then proceed.

Steps

1. Resolve branches

• Source: $0 if provided, else saved default, else main
• Target: $1 if provided, else current branch
• Direction: Always source → target

If source == target, error and stop.

2. Dry run check

If --dry-run:

git fetch origin
git log {target}..origin/{source} --oneline

Show what commits would be merged, then stop.

3. Stash uncommitted work

If working tree is dirty:

git stash --include-untracked

Record that a stash was created.

Record which branch the user was on originally.

4. Update source

git checkout {source}
git pull origin {source}

If pull fails → restore state, report error, stop.

5. Update and merge into target

git checkout {target}
git pull origin {target}
git merge {source} --no-edit

6. Handle conflicts

If merge reports conflicts:

1. List conflicts: git diff --name-only --diff-filter=U
2. Based on conflict resolution preference:

• preserve-both: Read each file, resolve keeping both sides
• ask-each: Show conflict to user via AskUserQuestion, let them decide
• prefer-source/target: Auto-resolve favoring chosen side

1. git add each resolved file
2. git commit --no-edit

7. Push

Unless --no-push or preference says no:

git push origin {target}

8. Restore state

1. Checkout original branch (if different from target)
2. If stash was created: git stash pop

9. Report

Synced {source} → {target}

  {source}:  {short sha} {subject}
  {target}:  {short sha} {subject}
  Conflicts: {count} ({file list} or "none")
  Pushed:    {yes/no}

10. Learn

If user changes source branch, save preference. If user changes conflict style, save preference.