Rebase PR Chain

Rebase a chain of dependent PRs so they are all up-to-date and mergeable.

1. Identify the Chain

Accept PR numbers from the user, or detect the chain automatically:

gh pr list --state open --json number,baseRefName,headRefName

Build the dependency graph: each PR's baseRefName points to the branch of the PR it depends on. Sort topologically (base branch first).

If the user provides explicit PR numbers (e.g. "33, 34, 35, 36, 37"), use that order directly.

2. Rebase Each PR

For each PR in the chain (starting from the one closest to the trunk):

a. Fetch and checkout

git fetch origin <baseRefName> <headRefName>
git checkout <headRefName>

Verify the working tree is clean.

b. Rebase

git rebase origin/<baseRefName>

If the rebase completes cleanly, skip to step (d).

c. Resolve Conflicts

Follow the same conflict resolution strategy as fix-pr-conflict:

1. List conflicting files: git diff --name-only --diff-filter=U
2. For each file, understand both sides and classify:
   • Mechanical: independent changes to nearby lines. Keep both.
   • Semantic: incompatible changes to the same logic. Resolve if the outcome is clear.
   • Ambiguous: design decisions or unclear intent. Abort the rebase (git rebase --abort) and escalate to the user with a description of the conflict.
3. After resolving: git add <file> then git rebase --continue
4. Repeat until the rebase completes or escalation is needed.

d. Verify

Run verification per verify-when-complete. Fix any issues from bad conflict resolution. If errors are unrelated, note them.

e. Force push

git push --force-with-lease

3. Verify Chain Mergeability

After all PRs are rebased, verify each is mergeable:

gh pr view <number> --json mergeable,mergeStateStatus

If GitHub still reports conflicts (recomputation delay), wait a few seconds and re-check once.

4. Report

Present a summary table:

PR	Branch	Status
#33	feature-a	Mergeable
#34	feature-b	Mergeable
#35	feature-c	Conflict (escalated)