Git Rebase

Git rebase and PR branch hygiene

Keep PR history clean. Treat rebases, non-fast-forward push rejections, and branch rewrites as topology problems, not file-content problems.

Required repo rules

• Read and follow root AGENTS.md and any nested AGENTS.md before changing files.
• Never use --force, --no-verify, or hook-bypass flags without explicit user approval.
• Prefer git push --force-with-lease over git push --force; still ask first.
• If hooks/checks fail, diagnose and fix or ask; do not bypass silently.
• Run pnpm format before committing. For verification, prefer targeted checks; avoid full pnpm typecheck by default because it is slow.
• For migration conflicts: never hand-write or hand-edit generated migration SQL, snapshots, or journal entries. Delete branch-local generated migration artifacts, rerun pnpm drizzle generate, then re-append intentional backfill SQL after generated DDL using --> statement-breakpoint separators.

Start every rebase/branch-cleanup task

git status --short --branch
branch=$(git branch --show-current)
git fetch origin main
git fetch origin "$branch" || true
git rev-list --count origin/main..HEAD
git log --oneline --decorate origin/main..HEAD
git log --oneline --left-right --graph HEAD...origin/$branch || true

Then state:

• current branch;
• whether the worktree is clean;
• local-only commit count and subjects;
• remote-only commits, if any;
• expected reviewable commit count, if known;
• whether the remote branch appears authoritative, stale, or uncertain.

Do not start a rebase with an unexplained dirty worktree. If on main or another protected/base branch, stop and ask.

If the user approves stashing dirty work, use a named stash and restore it after the rebase:

git stash push -u -m "pre-rebase-$branch-$(date +%Y%m%d%H%M%S)"
git stash list -1

After the rebase and verification, run git stash pop, report restored tracked/untracked files, and leave them unstaged unless the user asked otherwise.

Before rewriting local history

Create a backup branch unless the user explicitly declines:

backup="backup/${branch}-pre-rebase-$(date +%Y%m%d%H%M%S)"
git branch "$backup" HEAD

Use git rebase origin/main for normal base refreshes. Use interactive rebase only when the user asked to reorder/squash/edit commits or when you first explain the intended rewrite.

If post-rebase cleanup creates files that belong in an earlier logical commit, state the intended local rewrite before using git commit --fixup plus git rebase -i --autosquash or git commit --amend. Rerun final topology verification afterward.

After the rebase, verify topology and content:

git status --short --branch
git rev-list --count origin/main..HEAD
git log --oneline --decorate origin/main..HEAD
git diff --stat origin/main...HEAD
git range-diff origin/main...$backup origin/main...HEAD || true

After resolving conflicts, check resolved files for conflict markers and whitespace errors before final reporting:

rg -n '^<<<<<<<|^=======$|^>>>>>>>' <resolved-files> || true
git diff --check

If final content must match a backup/bad-history branch exactly:

git diff --quiet HEAD "$backup"
echo $?

Exit code 0 means file trees match.

Migration conflict procedure

When rebase conflicts touch packages/db/src/migrations/:

1. Identify branch-local generated migration artifacts. During an interrupted rebase, prefer the pre-rebase backup branch if HEAD no longer contains all branch commits:

   git diff --name-only --diff-filter=A origin/main...$backup -- packages/db/src/migrations
   git diff --name-only --diff-filter=A origin/main...HEAD -- packages/db/src/migrations
   

2. Do not manually resolve generated migration SQL, snapshots, or journal JSON.

3. Remove branch-local generated migration SQL, snapshot, and journal entries involved in the conflict.

4. If generated snapshot or journal conflicts block git rebase --continue, stage the current/base migration metadata as a temporary conflict resolution, then continue the rebase.

5. After the rebase reaches the target branch tip, rerun generation from the rebased schema:

   pnpm drizzle generate
   

6. Re-append any intentional backfill SQL after generated DDL with --> statement-breakpoint separators.

7. If regenerated migration files belong in an earlier logical commit, use the post-rebase cleanup guidance above.

8. Prefer a single regenerated migration per feature branch when it has not shipped.

Non-fast-forward push rejection

If git push is rejected as non-fast-forward, stop. Do not run git pull, git merge origin/$branch, or git merge reflexively.

Inspect divergence:

git fetch origin "$branch"
git log --oneline --left-right --graph HEAD...origin/$branch
git rev-list --count origin/main..HEAD
git rev-list --count origin/main..origin/$branch

Interpretation:

• < = local-only commits.
• > = remote-only commits.

Classify before acting:

• Remote is stale: remote-only commits are old/duplicate PR lineage and local branch is the cleaned intended history. Ask for approval to replace the remote with force-with-lease.
• Remote has real work: remote-only commits contain collaborator or authoritative changes. Ask whether to merge, rebase, or cherry-pick them.
• Uncertain: stop and ask.

After a base refresh, git log --left-right HEAD...origin/$branch may show new origin/main commits as local-only noise. Use range-diff and commit-subject comparison to classify the remote branch:

git range-diff origin/main...origin/$branch origin/main...HEAD || true

If range-diff shows the same PR commits rewritten onto the new base and no collaborator work, treat the remote as stale.

Use this approval prompt for stale remote history:

The remote PR branch appears stale. To keep the PR clean, I need to replace it with the local branch using git push --force-with-lease. Approve?

Only after approval:

expected=$(git rev-parse origin/$branch)
git branch "backup/${branch}-remote-before-rewrite-$(date +%Y%m%d%H%M%S)" "origin/$branch"
git push --force-with-lease=refs/heads/$branch:$expected origin HEAD:$branch

Then verify the remote:

git fetch origin "$branch"
git rev-list --count origin/main..origin/$branch
git log --oneline --decorate origin/main..origin/$branch

Clean-branch recovery for polluted PR history

Use when a PR branch has correct final content but duplicate/stale commits or merge pollution.

branch=$(git branch --show-current)
git branch "backup/${branch}-bad-history" HEAD
git fetch origin main
git switch -c "${branch}-clean" origin/main
git diff --no-ext-diff --binary origin/main "backup/${branch}-bad-history" > "/tmp/${branch}-clean.patch"
git apply "/tmp/${branch}-clean.patch"

Recreate logical commits manually in reviewable groups:

git add <paths>
git commit -m "type(scope): summary"

Before replacing the PR branch:

git rev-list --count origin/main..HEAD
git log --oneline --decorate origin/main..HEAD
git diff --quiet HEAD "backup/${branch}-bad-history"
echo $?

If the tree matches and the commit count is expected, ask for approval, then push with explicit lease.

Output contract

For rebase/push decisions, report:

Branch: <name>
Worktree: clean|dirty (<summary>)
Local commits vs origin/main: <count>
Remote divergence: none|stale|real-work|uncertain
Recommended action: <rebase|normal push|force-with-lease after approval|ask user|recover clean branch>
Approval needed: yes|no (<why>)
Verification: <commands run / commands still needed>