test(bundle): drive the lgtm cron's listing-500, closed-pr and evaluation-throw arms through dist/index.js

__tests__/bundle/cronLgtmFailureArms.test.ts

@@ -0,0 +1,97 @@
+import type { FakeGithub } from './fakeGithub'
+import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from 'vitest'
+
+import pullReqListPulls from '../fixtures/pullReq/pullReqListPulls.json'
+import { start } from './fakeGithub'
+import { configReads, helpersFor, ownersProbe, queueRead, repo, token } from './helpers'
+import { runBundle } from './runBundle'
+
+vi.setConfig({ testTimeout: 30_000 })
+
+// the arms of src/cronJobs/lgtm.ts that the schedule lgtm job cases in bundle.test.ts do not reach: a listing
+// that cannot be read, a closed pull request in the page, and a pull request whose evaluation throws
+describe('dist/index.js schedule lgtm job failure arms', () => {
+  const page1 = `GET ${repo}/pulls?state=open&page=1`
+  const page2 = `GET ${repo}/pulls?state=open&page=2`
+  const head = pullReqListPulls[0].head.sha
+  let gh: FakeGithub
+  const { expectRequests } = helpersFor(() => gh)
+
+  beforeAll(async () => {
+    gh = await start()
+  })
+  afterEach(() => gh.reset())
+  afterAll(() => gh.close())
+
+  function openPr(labels: string[], overrides: Record<string, unknown> = {}) {
+    const pr = structuredClone(pullReqListPulls[0])
+    return { ...pr, labels: labels.map(name => ({ name })), ...overrides }
+  }
+
+  function routePage(prs: Record<string, unknown>[]) {
+    gh.route('GET', new RegExp(`^${repo}/pulls\\?`), (req) => {
+      const page = new URL(req.path, gh.url).searchParams.get('page')
+      return { status: 200, body: page === '1' ? prs : [] }
+    })
+  }
+
+  function runCron() {
+    return runBundle({
+      eventName: 'schedule',
+      payload: {},
+      inputs: { ...token, 'jobs': 'lgtm', 'merge-method': 'squash' },
+      apiUrl: gh.url,
+    })
+  }
+
+  it('fails the run when the open pull request listing cannot be read, before any other call', async () => {
+    gh.route('GET', new RegExp(`^${repo}/pulls\\?`), { status: 500, body: { message: 'Internal Server Error' } })
+
+    const result = await runCron()
+
+    expect(result.status, result.stdout).toBe(1)
+    expect(result.errors.some(e => e.includes('error handling cron job: Error: could not get PRs: HttpError: Internal Server Error'))).toBe(true)
+    expect(gh.requestsMatching('PUT', /./)).toEqual([])
+    expectRequests(configReads(), [page1])
+  })
+
+  it('skips a closed pull request in the listing without reading it, and still merges its open sibling', async () => {
+    routePage([openPr(['lgtm'], { number: 3, state: 'closed' }), openPr(['lgtm'])])
+    gh.route('GET', `${repo}/pulls/2`, { status: 200, body: { ...openPr(['lgtm']), mergeable: true, mergeable_state: 'clean' } })
+    gh.commitStatuses(repo, head, [{ context: 'prow/lgtm', state: 'success' }])
+    gh.route('PUT', `${repo}/pulls/2/merge`, { status: 200, body: { merged: true } })
+
+    const result = await runCron()
+
+    expect(result.status, result.stdout).toBe(0)
+    expect(result.errors).toEqual([])
+    expect(result.stdout).toContain('processing pr: 3')
+    expect(result.stdout).toContain('merged pr #2')
+    expect(gh.requestsMatching('GET', /\/pulls\/3/)).toEqual([])
+    const merges = gh.requestsMatching('PUT', /\/pulls\/\d+\/merge$/)
+    expect(merges).toHaveLength(1)
+    expect(merges[0].body).toEqual({ merge_method: 'squash', sha: head })
+    // the closed pr is dropped before its base's gate is resolved: the tree is probed for #2 only
+    expectRequests(configReads(), [
+      page1,
+      ownersProbe,
+      `GET ${repo}/pulls/2`,
+      `GET ${repo}/commits/${head}/status?per_page=100`,
+      queueRead,
+      `PUT ${repo}/pulls/2/merge`,
+      page2,
+    ])
+  })
+
+  it('fails the run when a listed pull request cannot be re-read for evaluation, and stops paging', async () => {
+    routePage([openPr(['lgtm'])])
+    gh.route('GET', `${repo}/pulls/2`, { status: 500, body: { message: 'Internal Server Error' } })
+
+    const result = await runCron()
+
+    expect(result.status, result.stdout).toBe(1)
+    expect(result.errors.some(e => e.includes('error handling cron job: TypeError: error processing pr: HttpError: Internal Server Error'))).toBe(true)
+    expect(gh.requestsMatching('PUT', /./)).toEqual([])
+    expectRequests(configReads(), [page1, ownersProbe, `GET ${repo}/pulls/2`])
+  })
+})