cascade-rebase

name	cascade-rebase
description	Rebase a chain of stacked/dependent branches when main is updated.

Context

• Current branch: !git branch --show-current 2>/dev/null

Cascade Rebase

Rebase a chain of compound feature branches when the base (main) is updated.

Usage

• /cascade-rebase <branch1> <branch2> ... - Rebase branches in order
• /cascade-rebase - Will prompt for branch chain

Instructions

1. Get branch chain:

   • If $ARGUMENTS provided, parse as space-separated branch names
   • Otherwise, ask: "List your branches in order from closest to main to furthest (e.g., feature/phase1 feature/phase2 feature/phase3)"

2. Fetch and validate:

   git fetch origin main <all-branches>
   

   Verify all branches exist.

3. Record current commit hashes (needed for --onto):

   git rev-parse origin/<branch>
   

   Store as old_hash_<branch> for each branch.

4. Rebase first branch onto main:

   git checkout <branch1>
   git rebase origin/main
   

   Record new hash: new_hash_<branch1>=$(git rev-parse HEAD)

5. Cascade to subsequent branches: For each remaining branch:

   git checkout <branchN>
   git rebase --onto <new_hash_prev> <old_hash_prev> <branchN>
   

   Record: new_hash_<branchN>=$(git rev-parse HEAD)

   The --onto syntax:

   • <new_hash_prev>: Where to attach (tip of rebased previous branch)
   • <old_hash_prev>: Old parent to detach from
   • <branchN>: Current branch being rebased

6. Handle conflicts:

   • If rebase conflicts occur, pause and help resolve
   • After resolution: git rebase --continue
   • User can abort: git rebase --abort

7. Push all branches: Ask the operator: "Rebase complete. Push all branches with --force-with-lease?"

   git push origin <branch1> --force-with-lease
   git push origin <branch2> --force-with-lease
   # ... etc
   

8. Summary: Show old → new commit hashes for each branch.

Example

Cascade rebase: main → feature/phase1 → feature/phase2 → feature/phase3

Step 1: Rebasing feature/phase1 onto main...
  Done: abc123 → def456

Step 2: Rebasing feature/phase2 onto feature/phase1...
  Done: 111aaa → 222bbb

Step 3: Rebasing feature/phase3 onto feature/phase2...
  Done: 333ccc → 444ddd

All branches rebased. Ready to push.

Reference Files (conditional — read only when needed)

• rebase-patterns.md - Common rebase patterns and troubleshooting

Important Notes

• This rewrites history - ensure no one else is working on these branches
• Always use --force-with-lease (not --force) for safety
• If conflicts occur mid-chain, resolve before continuing