merge-queue-readiness git:20260709.c95f063A

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---
name: merge-queue-readiness
description: Pre-queue merge-group CI simulation. Triggered before adding a PR to a GitHub merge queue. Prevents merge-queue kick-outs from integration test failures.
---

# Merge Queue Readiness

## Trigger
Before adding the PR to the merge queue (or before the final push if the repo uses a merge queue).

## Protocol
1. **Fetch latest main:** `git fetch origin main`
2. **Run the simulation command (preferred):**
   ```
   /swarm ci-simulate --base origin/main --head <pr-branch>
   ```
   By default this runs fixed local CI gates: `bun run typecheck`,
   `bun run lint:ci`, `bun run build`, `bun run test:unit:ci`,
   integration/security/smoke tests, and `bun run drift:check`.
   `test:unit:ci` runs unit tests per file with the repo's quarantine filters
   and retry budget, matching CI's mock-isolation semantics. The command creates
   a temporary detached worktree under `.swarm/ci-simulate`, merges the PR branch
   or current worktree commit, runs the gate sequence, removes the worktree, and
   prunes metadata. It does not accept arbitrary shell commands.
3. **Manual fallback:** If the command is unavailable, create a temporary simulation worktree (do NOT mutate the PR branch). Use a project-relative path UNDER the swarm worktree base so the path is portable across OSes and its later removal is permitted by the worktree guardrail (paths outside `.swarm-worktrees/` are blocked). Do NOT hardcode `/tmp` — it does not exist on Windows.
   ```
   git worktree add .swarm-worktrees/merge-sim origin/main
   cd .swarm-worktrees/merge-sim
   git merge <pr-branch> --no-edit
   ```
4. **Run integration + unit tests against the merged result:**
   ```
   bun test tests/integration --timeout 120000
   bun test tests/unit --timeout 120000
   ```
   (Use per-file loops for hot modules per AGENTS.md invariant 6)
5. **If failures:** Fix on the PR branch, re-push, re-simulate. Always run the cleanup step (6) before re-simulating or on any exit path — do not leave the simulation worktree behind.
6. **Cleanup for manual fallback (run on EVERY exit path, including failure):** `git worktree remove --force .swarm-worktrees/merge-sim`. If the remove is guardrail-blocked or fails, delete the directory directly and run `git worktree prune`.
7. **Only after simulation passes,** add PR to the merge queue.

## Why this matters
PR-branch CI and merge-group CI test DIFFERENT things:
- PR-branch: tests the PR head commit in isolation
- Merge-group: tests a temporary merge of PR head + latest main

Integration tests that pass on the PR branch may fail in merge-group context due to test interactions exposed by the merged result.

## Automation
`/swarm ci-simulate` automates the merge-result worktree, merge, command run,
worktree removal, and metadata prune. Use the manual protocol only when the
command is unavailable or the repo needs bespoke setup.