Prune Merged Branches

Safely identify and remove git branches that have been merged into the base branch.

SAFETY: Dry-run by default. Use --execute to actually delete branches.

Integration

Can be run standalone or as part of repository maintenance. Related: /cleanup, /rollback

Options

• --execute - Actually delete branches (default is dry-run)
• --local-only - Only prune local branches
• --remote-only - Only prune remote branches
• --exclude <pattern> - Additional branch patterns to protect

Workflow

Step 1: Fetch Latest State

git fetch --prune

Step 2: Detect Base Branch

Auto-detect the default branch (main or master):

BASE=$(git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's@^refs/remotes/origin/@@')
if [ -z "$BASE" ]; then
  # Fallback: check which exists
  if git show-ref --verify --quiet refs/heads/main; then
    BASE="main"
  else
    BASE="master"
  fi
fi

Step 3: Identify Merged Branches

Protected branches (never delete):

• main, master, dev, develop, staging, production
• Current branch (the one you're on)
• Any branch matching user-provided --exclude pattern

Find merged local branches:

git branch --merged $BASE | grep -vE '^\*|^\s*(main|master|dev|develop|staging|production)\s*$'

Find merged remote branches:

git branch -r --merged origin/$BASE | grep -vE 'origin/(main|master|dev|develop|staging|production|HEAD)'

Step 3.5: Verify Release Branches

IMPORTANT: Before suggesting release branches for deletion, verify they have been properly released.

For each branch matching release/* or release-* pattern:

1. Extract version from branch name (e.g., release/v1.2.0 → v1.2.0)

2. Check for corresponding tag:

   git tag -l "v1.2.0" "1.2.0"  # Check both with and without 'v' prefix
   

3. Check for GitHub release (if gh CLI available):

   gh release view v1.2.0 --json tagName 2>/dev/null
   

4. Classification:

   • ✅ Safe to prune: Tag exists AND GitHub release exists
   • ⚠️ Warning: Tag exists but no GitHub release (may be intentional)
   • ❌ Protected: No tag found - do NOT suggest for deletion

Display release branch status:

### Release Branch Verification

| Branch         | Tag        | Release     | Status               |
| -------------- | ---------- | ----------- | -------------------- |
| release/v1.2.0 | ✅ v1.2.0  | ✅ Released | Safe to prune        |
| release/v1.3.0 | ✅ v1.3.0  | ❌ Missing  | ⚠️ Warn before prune |
| release/v1.4.0 | ❌ Missing | ❌ Missing  | 🛡️ Protected         |

Automatic protection: Release branches without a corresponding tag are automatically excluded from the prune candidates and added to the protected list.

Step 4: Display Candidates

Show all branches that would be deleted:

## Branches to Prune

### Local Branches

- feature/old-feature
- fix/completed-bugfix

### Remote Branches

- origin/feature/old-feature
- origin/fix/completed-bugfix

Total: X local, Y remote branches

Step 5: Execute (if --execute flag)

If --execute was NOT provided:

• Display the candidates only
• Remind user to run with --execute to delete

If --execute WAS provided:

• Confirm with user before proceeding
• Delete local branches: git branch -d <branch>
• Delete remote branches: git push origin --delete <branch>
• Report results

Step 6: Report

## Prune Results

### Deleted

- Local: X branches
- Remote: Y branches

### Skipped (protected)

- main, develop, etc.

### Release Branches Protected (no tag/release)

- release/v1.4.0 - No tag found

### Errors (if any)

- [branch]: [error message]

Safety Protocols

1. Dry-run default - Shows candidates without deleting unless --execute is used
2. Protected branches - main, master, dev, develop, staging, production are never deleted
3. Current branch - Never deletes the branch you're currently on
4. Merge verification - Only deletes branches confirmed merged via git branch --merged
5. Release branch verification - Release branches require a corresponding tag before pruning; branches without tags are automatically protected
6. Confirmation - Asks for confirmation before deleting when using --execute