pr-split

PR Split Command

Split a multi-feature pull request into smaller, focused PRs.

IMPORTANT: This command ALWAYS uses squash merge to discard try-and-error history and create clean, meaningful commits. Never use cherry-pick.

Process

1. Analyze Current PR

• Check current branch and commits
• Use gh pr view for PR details
• CRITICAL: Extract EXACT base branch using gh pr view --json baseRefName
• Extract original issue reference
• Run git log origin/<BASE>..HEAD (not main!)
• Identify distinct features/fixes

2. Determine if Split is Needed

• Check if PR contains multiple independent features
• If single feature, inform user split not needed
• If beneficial, explain what will be split

3. Plan the Split

• Use the EXACT base branch from step 1
• List distinct features/fixes to split
• Present plan for user approval

4. Execute Split

For each split feature:

a. Create new branch from base

git fetch origin
git checkout -b feature/split-name origin/<base-branch>

b. Apply changes using squash merge

git merge --squash original-branch

• Review staged changes

• Unstage files not related to this feature

• Create clean, logical commits

  CRITICAL - NO COMMIT ALTERATION:

• NEVER use git commit --amend

• NEVER use git rebase

c. Push and create PR

• Use gh pr create --base <base-branch>
• Include original issue reference FIRST
• Include old PR reference LAST

5. Handle Original PR

• Add [outdated] prefix to title
• Update description with references to new PRs
• Close with comment listing new PRs

Important Notes

• CRITICAL: ALWAYS use the original PR's base branch for ALL new PRs
• CRITICAL: Compare against the correct BASE branch
• CRITICAL: Never alter commits (no amend, no rebase, no force push)
• CRITICAL: Mark original PR as outdated
• All PR titles must be in Japanese (project requirement)
• Always use squash merge to create clean commits
• Ask for confirmation before executing