diff --git a/__tests__/bundle/shortBackoffPreload.cjs b/__tests__/bundle/shortBackoffPreload.cjs
new file mode 100644
index 00000000..a1c87acc
--- /dev/null
+++ b/__tests__/bundle/shortBackoffPreload.cjs
@@ -0,0 +1,15 @@
+// Preloaded into the bundle child with `NODE_OPTIONS=--require` by the tide e2e tests.
+// Shortens the `setTimeout` waits whose delays are listed (in ms, comma-separated) in
+// SHORT_BACKOFF_MS to SHORT_BACKOFF_TO_MS, so tide's 1s+2s+4s mergeability backoff runs
+// in milliseconds without changing what the bundle logs. Every other timer is untouched.
+'use strict'
+
+const shortened = new Set((process.env.SHORT_BACKOFF_MS ?? '').split(',').filter(Boolean).map(Number))
+const to = Number(process.env.SHORT_BACKOFF_TO_MS ?? '10')
+const realSetTimeout = globalThis.setTimeout
+
+function shortSetTimeout(callback, delay, ...args) {
+  return realSetTimeout(callback, shortened.has(delay) ? to : delay, ...args)
+}
+shortSetTimeout.__promisify__ = realSetTimeout.__promisify__
+globalThis.setTimeout = shortSetTimeout
diff --git a/__tests__/bundle/tideVerdictArms.test.ts b/__tests__/bundle/tideVerdictArms.test.ts
new file mode 100644
index 00000000..31cfc2e1
--- /dev/null
+++ b/__tests__/bundle/tideVerdictArms.test.ts
@@ -0,0 +1,280 @@
+import type { FakeGithub } from './fakeGithub'
+import path from 'node:path'
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import checkSuiteCompletedEvent from '../fixtures/pullReq/checkSuiteCompletedEvent.json'
+import pullReqListPulls from '../fixtures/pullReq/pullReqListPulls.json'
+import { prCommentEvent } from '../utils/ownersFixtures'
+import { start } from './fakeGithub'
+import { configReads, helpersFor, ownersProbe, queueRead, repo, token } from './helpers'
+import { runBundle } from './runBundle'
+
+vi.setConfig({ testTimeout: 30_000 })
+
+// shortens tide's 1s+2s+4s mergeability backoff inside the child; the logged delays are unchanged
+const preload = path.resolve(__dirname, 'shortBackoffPreload.cjs')
+const shortBackoff = { NODE_OPTIONS: `--require "${preload}"`, SHORT_BACKOFF_MS: '1000,2000,4000' }
+
+// the verdicts of tide's evaluateMerge that bundle.test.ts and mergeQueueArms.test.ts never reach — a pull
+// request GitHub reports as merged or locked, a mergeability that stays `unknown` through every
+// retry, a head that moves while it is computed, a merge refused because a sibling event landed first or
+// because the base moved under it, and a refused merge whose re-read fails too — plus tideOnComment's
+// closed pull request and tideOnCheckSuite's missing-sha and nothing-to-evaluate arms, all driven through
+// dist/index.js. `check_suite` is the vehicle: tide is its only handler, so the recorded traffic is tide's
+describe('dist/index.js tide verdicts', () => {
+  let gh: FakeGithub
+  const { expectRequests } = helpersFor(() => gh)
+
+  const pullRead = `GET ${repo}/pulls/1`
+  const merge = `PUT ${repo}/pulls/1/merge`
+  const head = checkSuiteCompletedEvent.check_suite.head_sha
+  const bindingRead = `GET ${repo}/commits/${head}/status?per_page=100`
+  const bound = [{ context: 'prow/lgtm', state: 'success' }]
+
+  beforeAll(async () => {
+    gh = await start()
+  })
+  beforeEach(() => gh.mergeQueueFallback({ pullRequestId: 'PR_none', headOid: head, enabled: false }))
+  afterEach(() => gh.reset())
+  afterAll(() => gh.close())
+
+  function pr(state: string, overrides: Record<string, unknown> = {}) {
+    const base = structuredClone(pullReqListPulls[0])
+    return {
+      ...base,
+      number: 1,
+      labels: [{ name: 'lgtm' }],
+      mergeable: state === 'unknown' ? null : true,
+      mergeable_state: state,
+      head: { sha: head },
+      ...overrides,
+    }
+  }
+
+  function checkSuite(pullRequests: { number: number }[] = [{ number: 1 }]) {
+    return runBundle({
+      eventName: 'check_suite',
+      payload: { ...checkSuiteCompletedEvent, check_suite: { ...checkSuiteCompletedEvent.check_suite, pull_requests: pullRequests } },
+      inputs: token,
+      apiUrl: gh.url,
+      env: shortBackoff,
+    })
+  }
+
+  describe('a pull request GitHub reports as', () => {
+    it.each([
+      ['merged', { merged: true }, 'already merged'],
+      ['locked', { locked: true }, 'locked'],
+    ])('%s is skipped before its lgtm binding or mergeability is read', async (_, overrides, reason) => {
+      gh.route('GET', `${repo}/pulls/1`, { status: 200, body: pr('clean', overrides) })
+
+      const result = await checkSuite()
+
+      expect(result.status, result.stdout).toBe(0)
+      expect(result.errors).toEqual([])
+      expect(result.stdout).toContain(`skipping pr #1: ${reason}`)
+      expect(gh.requestsMatching('PUT', /./)).toEqual([])
+      // the gate failed on an event, so tide asks the queue once whether its own entry must be dequeued
+      expectRequests(configReads(), [pullRead, ownersProbe, queueRead])
+    })
+  })
+
+  it('a mergeability still unknown after every retry is skipped as not mergeable (unknown)', async () => {
+    gh.commitStatuses(repo, head, bound)
+    gh.route('GET', `${repo}/pulls/1`, { status: 200, body: pr('unknown') })
+
+    const result = await checkSuite()
+
+    expect(result.status, result.stdout).toBe(0)
+    expect(result.errors).toEqual([])
+    for (const delay of [1000, 2000, 4000]) {
+      expect(result.stdout).toContain(`mergeability of pr #1 is not computed yet, retrying in ${delay}ms`)
+    }
+    expect(result.stdout).toContain('mergeability of pr #1 is still unknown after 3 retries')
+    expect(result.stdout).toContain('skipping pr #1: not mergeable (unknown)')
+    expect(gh.requestsMatching('PUT', /./)).toEqual([])
+    // the first read, then one re-read per retry
+    expectRequests(configReads(), [pullRead, ownersProbe, bindingRead, queueRead, pullRead, pullRead, pullRead])
+  })
+
+  it('a head that moves while mergeability is computed is skipped, not merged', async () => {
+    gh.commitStatuses(repo, head, bound)
+    gh.routeSequence('GET', `${repo}/pulls/1`, [
+      { status: 200, body: pr('unknown') },
+      { status: 200, body: pr('clean', { head: { sha: 'movedsha' } }) },
+    ])
+
+    const result = await checkSuite()
+
+    expect(result.status, result.stdout).toBe(0)
+    expect(result.errors).toEqual([])
+    expect(result.stdout).toContain('skipping pr #1: head moved during evaluation')
+    expect(gh.requestsMatching('PUT', /./)).toEqual([])
+    expectRequests(configReads(), [pullRead, ownersProbe, bindingRead, queueRead, pullRead])
+  })
+
+  describe('a merge GitHub refuses', () => {
+    it('with 405 once a concurrent event merged it is reported as merged concurrently, exit 0', async () => {
+      gh.commitStatuses(repo, head, bound)
+      gh.routeSequence('GET', `${repo}/pulls/1`, [
+        { status: 200, body: pr('clean') },
+        { status: 200, body: pr('clean', { merged: true, state: 'closed' }) },
+      ])
+      gh.route('PUT', `${repo}/pulls/1/merge`, { status: 405, body: { message: 'Pull Request is not mergeable' } })
+
+      const result = await checkSuite()
+
+      expect(result.status, result.stdout).toBe(0)
+      expect(result.errors).toEqual([])
+      expect(result.stdout).toContain('pr #1 was merged concurrently')
+      expect(result.stdout).not.toContain('could not merge pr #1')
+      expect(gh.requestsMatching('PUT', /./)[0].body).toEqual({ merge_method: 'merge', sha: head })
+      // the refused merge is followed by one re-read that finds the pull request merged
+      expectRequests(configReads(), [pullRead, ownersProbe, bindingRead, queueRead, merge, pullRead])
+    })
+
+    it.each([
+      ['Base branch was modified. Review and try the merge again.', 'base branch moved'],
+      ['Head branch was modified. Review and try the merge again.', 'head moved'],
+    ])('with 409 "%s" is skipped as %s, exit 0', async (message, reason) => {
+      gh.commitStatuses(repo, head, bound)
+      gh.route('GET', `${repo}/pulls/1`, { status: 200, body: pr('clean') })
+      gh.route('PUT', `${repo}/pulls/1/merge`, { status: 409, body: { message } })
+
+      const result = await checkSuite()
+
+      expect(result.status, result.stdout).toBe(0)
+      expect(result.errors).toEqual([])
+      expect(result.stdout).toContain(`skipping pr #1: ${reason}`)
+      expect(result.stdout).not.toContain('could not merge pr #1')
+      expectRequests(configReads(), [pullRead, ownersProbe, bindingRead, queueRead, merge, pullRead])
+    })
+
+    it('whose re-read fails too is reported with GitHub\'s message and fails the run', async () => {
+      gh.commitStatuses(repo, head, bound)
+      gh.routeSequence('GET', `${repo}/pulls/1`, [
+        { status: 200, body: pr('clean') },
+        { status: 500, body: { message: 'boom' } },
+      ])
+      gh.route('PUT', `${repo}/pulls/1/merge`, { status: 500, body: { message: 'merge exploded' } })
+
+      const result = await checkSuite()
+
+      expect(result.status, result.stdout).toBe(1)
+      expect(result.errors).toHaveLength(2)
+      expect(result.errors.some(e => e.includes('merge exploded'))).toBe(true)
+      expect(result.errors.some(e => e.includes('could not merge pull request(s) #1'))).toBe(true)
+      expectRequests(configReads(), [pullRead, ownersProbe, bindingRead, queueRead, merge, pullRead])
+    })
+  })
+
+  describe('check_suite', () => {
+    it('without a head sha fails the run naming the payload', async () => {
+      const result = await runBundle({
+        eventName: 'check_suite',
+        payload: { action: 'completed', check_suite: { conclusion: 'success' }, repository: checkSuiteCompletedEvent.repository },
+        inputs: token,
+        apiUrl: gh.url,
+      })
+
+      expect(result.status, result.stdout).toBe(1)
+      expect(result.errors).toHaveLength(1)
+      expect(result.errors[0]).toContain('error handling check_suite event: github context payload missing head sha: {"action":"completed","check_suite":{"conclusion":"success"}')
+      expect(gh.requests).toEqual([])
+    })
+
+    it('naming no pull request, for a commit no open pull request has as its head, evaluates nothing', async () => {
+      gh.route('GET', new RegExp(`^${repo}/pulls\\?`), (req) => {
+        const page = new URL(req.path, gh.url).searchParams.get('page')
+        return { status: 200, body: page === '1' ? [{ number: 2, head: { sha: 'other' } }] : [] }
+      })
+
+      const result = await checkSuite([])
+
+      expect(result.status, result.stdout).toBe(0)
+      expect(result.errors).toEqual([])
+      expect(result.stdout).toContain('tide: no open pull request to evaluate')
+      expectRequests(configReads(), [
+        `GET ${repo}/pulls?state=open&per_page=100&page=1`,
+        `GET ${repo}/pulls?state=open&per_page=100&page=2`,
+      ])
+    })
+  })
+
+  it('issue_comment /hold on a closed pull request applies the label; tide skips the closed pull request without reading it', async () => {
+    gh.route('GET', `${repo}/labels`, { status: 200, body: [{ name: 'do-not-merge/hold' }] })
+    gh.route('POST', `${repo}/issues/1/labels`, { status: 200, body: [] })
+    const payload = prCommentEvent('/hold')
+
+    const result = await runBundle({
+      eventName: 'issue_comment',
+      payload: { ...payload, issue: { ...payload.issue, state: 'closed' } },
+      inputs: { ...token, 'prow-commands': '/hold' },
+      apiUrl: gh.url,
+    })
+
+    expect(result.status, result.stdout).toBe(0)
+    expect(result.errors).toEqual([])
+    expect(result.stdout).toContain('tide: pull request #1 is closed')
+    expect(gh.requestsMatching('POST', /\/issues\/1\/labels$/)[0].body).toEqual({ labels: ['do-not-merge/hold'] })
+    expect(gh.requestsMatching('GET', /\/pulls\/1$/)).toEqual([])
+  })
+})
+
+// the scheduled `sweep` and `lgtm` jobs overlap: both list the open pull requests and both reach the merge
+// path, so tide evaluates each pull request once per run — the second job to arrive is skipped, not merged twice
+describe('dist/index.js schedule with both the sweep and the lgtm jobs', () => {
+  let gh: FakeGithub
+
+  const head = pullReqListPulls[0].head.sha
+
+  beforeAll(async () => {
+    gh = await start()
+  })
+  beforeEach(() => gh.mergeQueueFallback({ pullRequestId: 'PR_none', headOid: head, enabled: false }))
+  afterEach(() => gh.reset())
+  afterAll(() => gh.close())
+
+  it('evaluates a pull request both jobs list once: one merge, the other job skips it as already evaluated', async () => {
+    const stamp = new Date().toISOString()
+    const pr = {
+      ...structuredClone(pullReqListPulls[0]),
+      number: 1,
+      labels: [{ name: 'lgtm' }],
+      created_at: stamp,
+      updated_at: stamp,
+      requested_reviewers: [],
+      assignees: [],
+      draft: false,
+      mergeable: true,
+      mergeable_state: 'clean',
+      head: { sha: head, repo: { full_name: 'Codertocat/Hello-World' } },
+      base: { ref: 'master', sha: 'basesha' },
+    }
+    gh.route('GET', repo, { status: 200, body: { default_branch: 'master' } })
+    gh.route('GET', new RegExp(`^${repo}/pulls\\?`), (req) => {
+      const page = new URL(req.path, gh.url).searchParams.get('page')
+      return { status: 200, body: page === '1' ? [pr] : [] }
+    })
+    gh.route('GET', `${repo}/pulls/1`, { status: 200, body: pr })
+    gh.commitStatuses(repo, head, [{ context: 'prow/lgtm', state: 'success' }])
+    gh.route('PUT', `${repo}/pulls/1/merge`, { status: 200, body: { merged: true } })
+
+    const result = await runBundle({
+      eventName: 'schedule',
+      payload: {},
+      inputs: { ...token, jobs: 'sweep lgtm' },
+      apiUrl: gh.url,
+    })
+
+    expect(result.status, result.stdout).toBe(0)
+    expect(result.errors).toEqual([])
+    expect(result.stdout).toContain('merged pr #1')
+    expect(result.stdout).toContain('skipping pr #1: already evaluated in this run')
+    expect(gh.requestsMatching('PUT', /./)).toHaveLength(1)
+    expect(gh.requestsMatching('PUT', /./)[0].body).toEqual({ merge_method: 'merge', sha: head })
+    // the jobs run concurrently, so only the listings' presence is fixed, not their order
+    expect(gh.requestsMatching('GET', /\/pulls\?state=open&sort=updated&direction=desc&per_page=100&page=1$/)).toHaveLength(1)
+    expect(gh.requestsMatching('GET', /\/pulls\?state=open&page=1$/)).toHaveLength(1)
+  })
+})