test(bundle): fold the sweep memo case into sweepArms, drop the root OWNERS approver case

__tests__/bundle/authorizationPolicyArms.test.ts

@@ -97,24 +97,6 @@ describe('dist/index.js authorization policy arms', () => {
       expectRequests(configReads({ repo: '.github/prow.yaml' }), [...membershipReads('rita'), rootOwnersRead, labelsRead, labelPost])
     })
 
-    it('under labels: trusted, by a root OWNERS approver who is not a reviewer: admitted by the approvers list', async () => {
-      routeConfig(triageConfig('trusted'))
-      gh.route('GET', '/orgs/Codertocat/members/alice', notFound)
-      gh.route('GET', `${repo}/collaborators/alice`, notFound)
-      gh.route('GET', `${repo}/contents/OWNERS`, {
-        status: 200,
-        body: { type: 'file', encoding: 'base64', content: Buffer.from('reviewers:\n- rita\napprovers:\n- Alice\n').toString('base64') },
-      })
-      routeLabelWrite()
-
-      const result = await triage('alice')
-
-      expect(result.status, result.stdout).toBe(0)
-      expect(result.errors).toEqual([])
-      expect(gh.requestsMatching('POST', /\/issues\/1\/labels$/)[0].body).toEqual({ labels: ['triage/accepted'] })
-      expectRequests(configReads({ repo: '.github/prow.yaml' }), [...membershipReads('alice'), rootOwnersRead, labelsRead, labelPost])
-    })
-
     it('under labels: collaborators, with no commenter login in the payload: refused before any read', async () => {
       routeConfig(triageConfig('collaborators'))
       const payload = comment('/triage accepted') as Record<string, any>

__tests__/bundle/sweepArms.test.ts

@@ -1,16 +1,19 @@
 import type { FakeGithub } from './fakeGithub'
+import { Buffer } from 'node:buffer'
 import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from 'vitest'
 
+import labelFileContents from '../fixtures/labels/labelFileContentsResp.json'
 import pullReqListPulls from '../fixtures/pullReq/pullReqListPulls.json'
-import { blobSha } from '../utils/ownersData'
+import { blobSha, pullBody } from '../utils/ownersData'
 import { start } from './fakeGithub'
 import { configReads, helpersFor, repo, token } from './helpers'
 import { runBundle } from './runBundle'
 
 vi.setConfig({ testTimeout: 30_000 })
 
-// the arms of the sweep cron itself — an empty window, a failed listing, and blunderbuss's freshness guards on a
-// repository with OWNERS files — driven through dist/index.js like the merge paths in bundle.test.ts
+// the arms of the sweep cron itself — an empty window, a failed listing, blunderbuss's freshness guards on a
+// repository with OWNERS files, and the memos shared between pull requests — driven through dist/index.js like the
+// merge paths in bundle.test.ts
 describe('dist/index.js schedule sweep job arms', () => {
   let gh: FakeGithub
   const { expectRequests, routeOwners } = helpersFor(() => gh)
@@ -151,4 +154,59 @@ describe('dist/index.js schedule sweep job arms', () => {
       expect(requestedReviewers()).toEqual([])
     })
   })
+
+  // the token's identity (approveReview.ts tokenIdentity, read for `approve.github_review`) and the tip of the base
+  // branch (pullRequestOwners.ts baseBranchTip) are memoized per process, and a single event asks for each only once:
+  // the memo-hit arms are reachable only from a sweep over two pull requests sharing a base branch
+  describe('shared memos across pull requests', () => {
+    const ownersFiles: Record<string, string> = { 'sdk/OWNERS': 'approvers:\n- bob\n' }
+    const approveComment = { id: 1, body: '/approve', user: { login: 'bob', type: 'User' }, created_at: '2024-01-01T00:00:01Z' }
+
+    // two pull requests on master, opened before the window so blunderbuss has nothing to do, with
+    // `approve.github_review` on and GET /user answering for the token
+    function routeSweep() {
+      const opened = '2011-01-26T19:01:12Z'
+      const first = forkPr({ created_at: opened })
+      const second = forkPr({ number: 2, head: { sha: 'sha2', repo: { full_name: 'dave/Hello-World' } }, created_at: opened })
+      const config = structuredClone(labelFileContents)
+      config.content = Buffer.from('approve:\n  github_review: true\n').toString('base64')
+      gh.route('GET', `${repo}/contents/.github%2Fprow.yaml`, { status: 200, body: config })
+      gh.route('GET', '/user', { status: 200, body: { login: 'prow-bot' } })
+      routeList([first, second])
+      gh.route('GET', `${repo}/git/trees/master`, { status: 200, body: { sha: 'master', truncated: false, tree: Object.keys(ownersFiles).map(path => ({ path, type: 'blob', sha: blobSha(path) })) } })
+      routeOwners(ownersFiles, ['sdk/x.go'], first)
+      gh.route('GET', `${repo}/pulls/2`, { status: 200, body: { ...pullBody, ...second } })
+      gh.route('GET', `${repo}/pulls/2/files`, { status: 200, body: [{ filename: 'sdk/x.go', status: 'modified' }] })
+      gh.route('GET', new RegExp(`^${repo}/issues/\\d+$`), { status: 200, body: { labels: [] } })
+      gh.route('GET', `${repo}/labels`, { status: 200, body: [{ name: 'approved' }, { name: 'lgtm' }] })
+      gh.route('POST', new RegExp(`^${repo}/issues/\\d+/labels$`), { status: 200, body: [] })
+      gh.route('GET', new RegExp(`^${repo}/issues/\\d+/comments`), { status: 200, body: [approveComment] })
+      gh.route('POST', new RegExp(`^${repo}/issues/\\d+/comments$`), { status: 201, body: {} })
+      gh.route('GET', new RegExp(`^${repo}/pulls/\\d+/reviews`), { status: 200, body: [] })
+      gh.route('POST', new RegExp(`^${repo}/pulls/\\d+/reviews$`), { status: 200, body: { id: 9 } })
+      gh.route('GET', '/repos/Codertocat/.project/contents/prow.yaml', { status: 404, body: { message: 'Not Found' } })
+    }
+
+    function reads(pathRegex: RegExp) {
+      return gh.requestsMatching('GET', pathRegex).map(r => `GET ${r.path}`)
+    }
+
+    it('two pull requests on one base branch: GET /user and the branch tip are each read once, and both are approved', async () => {
+      routeSweep()
+
+      const result = await runSweep()
+
+      expect(result.status, result.stdout).toBe(0)
+      expect(result.errors).toEqual([])
+      expect(result.stdout).toContain('sweep: 2 candidates updated since')
+      expect(result.stdout).toContain('sweep: #1 evaluated')
+      expect(result.stdout).toContain('sweep: #2 evaluated')
+      // each pull request read its own changed files; the identity and the tip were shared
+      expect(reads(/\/pulls\/\d+\/files/).sort()).toEqual([`GET ${repo}/pulls/1/files?per_page=100`, `GET ${repo}/pulls/2/files?per_page=100`])
+      expect(reads(/^\/user$/)).toEqual(['GET /user'])
+      expect(reads(/\/branches\/master$/)).toEqual([`GET ${repo}/branches/master`])
+      expect(gh.requestsMatching('POST', /\/issues\/\d+\/labels$/).map(r => r.body)).toEqual([{ labels: ['approved'] }, { labels: ['approved'] }])
+      expect(gh.requestsMatching('POST', /\/pulls\/\d+\/reviews$/)).toHaveLength(2)
+    })
+  })
 })