From 7f4232cbdb60a4475c565e5d262b25182e47baf4 Mon Sep 17 00:00:00 2001
From: Oscar Bazaldua <511911+oscb@users.noreply.github.com>
Date: Tue, 12 Sep 2023 11:56:40 -0700
Subject: [PATCH] feat: support custom global analytics key (#928)

---
 .changeset/mean-apricots-hammer.md            |  6 +++
 .../with-next-js/pages/partytown/index.tsx    |  2 +-
 .../analytics-pre-init.integration.test.ts    | 25 +++++++++
 .../browser/src/browser/__tests__/cdn.test.ts |  4 +-
 .../src/browser/__tests__/integration.test.ts | 54 ++++++++++++++++++-
 .../__tests__/standalone-analytics.test.ts    |  9 ++--
 .../src/browser/__tests__/standalone.test.ts  |  7 +--
 packages/browser/src/browser/index.ts         |  3 ++
 .../src/browser/standalone-analytics.ts       | 36 +++++--------
 .../src/browser/standalone-interface.ts       | 11 ++++
 packages/browser/src/core/analytics/index.ts  |  8 ++-
 packages/browser/src/core/buffer/snippet.ts   |  9 ++--
 packages/browser/src/index.ts                 |  3 +-
 .../src/lib/__tests__/parse-cdn.test.ts       |  2 +
 .../src/lib/global-analytics-helper.ts        | 31 +++++++++++
 packages/browser/src/lib/parse-cdn.ts         | 10 ++--
 packages/browser/src/tester/ajs-tester.ts     | 14 ++---
 .../src/task/__tests__/task-group.test.ts     | 26 +++++++++
 18 files changed, 210 insertions(+), 50 deletions(-)
 create mode 100644 .changeset/mean-apricots-hammer.md
 create mode 100644 packages/browser/src/browser/standalone-interface.ts
 create mode 100644 packages/browser/src/lib/global-analytics-helper.ts
 create mode 100644 packages/core/src/task/__tests__/task-group.test.ts

diff --git a/.changeset/mean-apricots-hammer.md b/.changeset/mean-apricots-hammer.md
new file mode 100644
index 000000000..76b8b9065
--- /dev/null
+++ b/.changeset/mean-apricots-hammer.md
@@ -0,0 +1,6 @@
+---
+'@segment/analytics-next': minor
+'@segment/analytics-core': minor
+---
+
+Adds `globalAnalyticsKey` option for setting custom global window buffers
diff --git a/examples/with-next-js/pages/partytown/index.tsx b/examples/with-next-js/pages/partytown/index.tsx
index 26b0a5287..e9493162a 100644
--- a/examples/with-next-js/pages/partytown/index.tsx
+++ b/examples/with-next-js/pages/partytown/index.tsx
@@ -44,7 +44,7 @@ const WebWorker: React.FC = () => {
           }}
           value="Track!"
           onClick={() => {
-            void window.analytics.track(
+            void (window as any).analytics.track(
               'Party Town Click',
               { myProp: 'hello' },
               { traits: { age: 8 } }
diff --git a/packages/browser/src/browser/__tests__/analytics-pre-init.integration.test.ts b/packages/browser/src/browser/__tests__/analytics-pre-init.integration.test.ts
index 7fd14c276..10384fca6 100644
--- a/packages/browser/src/browser/__tests__/analytics-pre-init.integration.test.ts
+++ b/packages/browser/src/browser/__tests__/analytics-pre-init.integration.test.ts
@@ -278,6 +278,31 @@ describe('Pre-initialization', () => {
       expect(onTrackCb).toBeCalledWith('foo', {}, undefined)
       expect(onTrackCb).toBeCalledWith('bar', {}, undefined)
     })
+    test('events can be buffered under a custom window key', async () => {
+      const onTrackCb = jest.fn()
+      const onTrack = ['on', 'track', onTrackCb]
+      const track = ['track', 'foo']
+      const track2 = ['track', 'bar']
+      const identify = ['identify']
+
+      ;(window as any).segment = [onTrack, track, track2, identify]
+
+      await AnalyticsBrowser.standalone(writeKey, {
+        globalAnalyticsKey: 'segment',
+      })
+
+      await sleep(100) // the snippet does not return a promise (pre-initialization) ... it sometimes has a callback as the third argument.
+      expect(trackSpy).toBeCalledWith('foo')
+      expect(trackSpy).toBeCalledWith('bar')
+      expect(trackSpy).toBeCalledTimes(2)
+
+      expect(identifySpy).toBeCalledTimes(1)
+
+      expect(getOnSpyCalls('track').length).toBe(1)
+      expect(onTrackCb).toBeCalledTimes(2) // gets called once for each track event
+      expect(onTrackCb).toBeCalledWith('foo', {}, undefined)
+      expect(onTrackCb).toBeCalledWith('bar', {}, undefined)
+    })
   })
 
   describe('Emitter methods', () => {
diff --git a/packages/browser/src/browser/__tests__/cdn.test.ts b/packages/browser/src/browser/__tests__/cdn.test.ts
index 76b15b694..a1d0e3ddc 100644
--- a/packages/browser/src/browser/__tests__/cdn.test.ts
+++ b/packages/browser/src/browser/__tests__/cdn.test.ts
@@ -1,4 +1,4 @@
-import { AnalyticsBrowser } from '../..'
+import { AnalyticsBrowser, getGlobalAnalytics } from '../..'
 import unfetch from 'unfetch'
 import { createSuccess } from '../../test-helpers/factories'
 import { setGlobalCDNUrl } from '../../lib/parse-cdn'
@@ -45,5 +45,5 @@ it('if CDN is overridden, sets the overridden CDN global variable', async () =>
     writeKey,
     cdnURL: mockCdn,
   })
-  expect(window.analytics._cdn).toBe(mockCdn)
+  expect(getGlobalAnalytics()?._cdn).toBe(mockCdn)
 })
diff --git a/packages/browser/src/browser/__tests__/integration.test.ts b/packages/browser/src/browser/__tests__/integration.test.ts
index e9b751902..f66471157 100644
--- a/packages/browser/src/browser/__tests__/integration.test.ts
+++ b/packages/browser/src/browser/__tests__/integration.test.ts
@@ -23,6 +23,7 @@ import {
   highEntropyTestData,
   lowEntropyTestData,
 } from '../../test-helpers/fixtures/client-hints'
+import { getGlobalAnalytics } from '../..'
 
 let fetchCalls: ReturnType<typeof parseFetchCall>[] = []
 
@@ -200,7 +201,7 @@ describe('Initialization', () => {
           {
             ...xt,
             load: async () => {
-              expect(window.analytics).toBeUndefined()
+              expect(getGlobalAnalytics()).toBeUndefined()
               expect(getCDN()).toContain(overriddenCDNUrl)
             },
           },
@@ -212,6 +213,57 @@ describe('Initialization', () => {
     })
   })
 
+  describe('globalAnalyticsKey', () => {
+    const overrideKey = 'myKey'
+    const buffer = {
+      foo: 'bar',
+    }
+
+    beforeEach(() => {
+      ;(window as any)[overrideKey] = buffer
+    })
+    afterEach(() => {
+      delete (window as any)[overrideKey]
+    })
+    it('should default to window.analytics', async () => {
+      const defaultObj = { original: 'default' }
+      ;(window as any)['analytics'] = defaultObj
+
+      await AnalyticsBrowser.load({
+        writeKey,
+        plugins: [
+          {
+            ...xt,
+            load: async () => {
+              expect(getGlobalAnalytics()).toBe(defaultObj)
+            },
+          },
+        ],
+      })
+      expect.assertions(1)
+    })
+
+    it('should set the global window key for the analytics buffer with the setting option', async () => {
+      await AnalyticsBrowser.load(
+        {
+          writeKey,
+          plugins: [
+            {
+              ...xt,
+              load: async () => {
+                expect(getGlobalAnalytics()).toBe(buffer)
+              },
+            },
+          ],
+        },
+        {
+          globalAnalyticsKey: overrideKey,
+        }
+      )
+      expect.assertions(1)
+    })
+  })
+
   describe('Load options', () => {
     it('gets high entropy client hints if set', async () => {
       ;(window.navigator as any).userAgentData = {
diff --git a/packages/browser/src/browser/__tests__/standalone-analytics.test.ts b/packages/browser/src/browser/__tests__/standalone-analytics.test.ts
index ede23fc4b..c13c5f426 100644
--- a/packages/browser/src/browser/__tests__/standalone-analytics.test.ts
+++ b/packages/browser/src/browser/__tests__/standalone-analytics.test.ts
@@ -1,13 +1,14 @@
 import jsdom, { JSDOM } from 'jsdom'
-import { InitOptions } from '../../'
+import { InitOptions, getGlobalAnalytics } from '../../'
 import { AnalyticsBrowser, loadLegacySettings } from '../../browser'
 import { snippet } from '../../tester/__fixtures__/segment-snippet'
-import { install, AnalyticsStandalone } from '../standalone-analytics'
+import { install } from '../standalone-analytics'
 import unfetch from 'unfetch'
 import { PersistedPriorityQueue } from '../../lib/priority-queue/persisted'
 import { sleep } from '../../lib/sleep'
 import * as Factory from '../../test-helpers/factories'
 import { EventQueue } from '../../core/queue/event-queue'
+import { AnalyticsStandalone } from '../standalone-interface'
 
 const track = jest.fn()
 const identify = jest.fn()
@@ -142,7 +143,7 @@ describe('standalone bundle', () => {
       .mockImplementation((): Promise<Response> => fetchSettings)
     const mockCdn = 'http://my-overridden-cdn.com'
 
-    window.analytics._cdn = mockCdn
+    getGlobalAnalytics()!._cdn = mockCdn
     await loadLegacySettings(segmentDotCom)
 
     expect(unfetch).toHaveBeenCalledWith(expect.stringContaining(mockCdn))
@@ -262,7 +263,7 @@ describe('standalone bundle', () => {
 
     // register is called after flushPreBuffer in `loadAnalytics`
     register.mockImplementationOnce(() =>
-      window.analytics.track('race conditions', { foo: 'bar' })
+      getGlobalAnalytics()?.track('race conditions', { foo: 'bar' })
     )
 
     await install()
diff --git a/packages/browser/src/browser/__tests__/standalone.test.ts b/packages/browser/src/browser/__tests__/standalone.test.ts
index a163ad8fb..0f2780b5e 100644
--- a/packages/browser/src/browser/__tests__/standalone.test.ts
+++ b/packages/browser/src/browser/__tests__/standalone.test.ts
@@ -4,6 +4,7 @@ import { LegacySettings } from '..'
 import { pWhile } from '../../lib/p-while'
 import { snippet } from '../../tester/__fixtures__/segment-snippet'
 import * as Factory from '../../test-helpers/factories'
+import { getGlobalAnalytics } from '../..'
 
 const cdnResponse: LegacySettings = {
   integrations: {
@@ -86,11 +87,11 @@ describe('standalone bundle', () => {
     await import('../standalone')
 
     await pWhile(
-      () => window.analytics?.initialized !== true,
+      () => getGlobalAnalytics()?.initialized !== true,
       () => {}
     )
 
-    expect(window.analytics).not.toBeUndefined()
-    expect(window.analytics.initialized).toBe(true)
+    expect(getGlobalAnalytics()).not.toBeUndefined()
+    expect(getGlobalAnalytics()?.initialized).toBe(true)
   })
 })
diff --git a/packages/browser/src/browser/index.ts b/packages/browser/src/browser/index.ts
index 095b8ae99..1c59af549 100644
--- a/packages/browser/src/browser/index.ts
+++ b/packages/browser/src/browser/index.ts
@@ -30,6 +30,7 @@ import { popSnippetWindowBuffer } from '../core/buffer/snippet'
 import { ClassicIntegrationSource } from '../plugins/ajs-destination/types'
 import { attachInspector } from '../core/inspector'
 import { Stats } from '../core/stats'
+import { setGlobalAnalyticsKey } from '../lib/global-analytics-helper'
 
 export interface LegacyIntegrationConfiguration {
   /* @deprecated - This does not indicate browser types anymore */
@@ -303,6 +304,8 @@ async function loadAnalytics(
   options: InitOptions = {},
   preInitBuffer: PreInitMethodCallBuffer
 ): Promise<[Analytics, Context]> {
+  if (options.globalAnalyticsKey)
+    setGlobalAnalyticsKey(options.globalAnalyticsKey)
   // this is an ugly side-effect, but it's for the benefits of the plugins that get their cdn via getCDN()
   if (settings.cdnURL) setGlobalCDNUrl(settings.cdnURL)
 
diff --git a/packages/browser/src/browser/standalone-analytics.ts b/packages/browser/src/browser/standalone-analytics.ts
index b89488006..b4f52c9c1 100644
--- a/packages/browser/src/browser/standalone-analytics.ts
+++ b/packages/browser/src/browser/standalone-analytics.ts
@@ -1,30 +1,19 @@
-import { Analytics, InitOptions } from '../core/analytics'
 import { AnalyticsBrowser } from '.'
 import { embeddedWriteKey } from '../lib/embedded-write-key'
-
-export interface AnalyticsSnippet extends AnalyticsStandalone {
-  load: (writeKey: string, options?: InitOptions) => void
-}
-
-export interface AnalyticsStandalone extends Analytics {
-  _loadOptions?: InitOptions
-  _writeKey?: string
-  _cdn?: string
-}
-
-declare global {
-  interface Window {
-    analytics: AnalyticsSnippet
-  }
-}
+import { AnalyticsSnippet } from './standalone-interface'
+import {
+  getGlobalAnalytics,
+  setGlobalAnalytics,
+} from '../lib/global-analytics-helper'
 
 function getWriteKey(): string | undefined {
   if (embeddedWriteKey()) {
     return embeddedWriteKey()
   }
 
-  if (window.analytics._writeKey) {
-    return window.analytics._writeKey
+  const analytics = getGlobalAnalytics()
+  if (analytics?._writeKey) {
+    return analytics._writeKey
   }
 
   const regex = /http.*\/analytics\.js\/v1\/([^/]*)(\/platform)?\/analytics.*/
@@ -59,7 +48,7 @@ function getWriteKey(): string | undefined {
 
 export async function install(): Promise<void> {
   const writeKey = getWriteKey()
-  const options = window.analytics?._loadOptions ?? {}
+  const options = getGlobalAnalytics()?._loadOptions ?? {}
   if (!writeKey) {
     console.error(
       'Failed to load Write Key. Make sure to use the latest version of the Segment snippet, which can be found in your source settings.'
@@ -67,8 +56,7 @@ export async function install(): Promise<void> {
     return
   }
 
-  window.analytics = (await AnalyticsBrowser.standalone(
-    writeKey,
-    options
-  )) as AnalyticsSnippet
+  setGlobalAnalytics(
+    (await AnalyticsBrowser.standalone(writeKey, options)) as AnalyticsSnippet
+  )
 }
diff --git a/packages/browser/src/browser/standalone-interface.ts b/packages/browser/src/browser/standalone-interface.ts
new file mode 100644
index 000000000..3288399ab
--- /dev/null
+++ b/packages/browser/src/browser/standalone-interface.ts
@@ -0,0 +1,11 @@
+import { Analytics, InitOptions } from '../core/analytics'
+
+export interface AnalyticsSnippet extends AnalyticsStandalone {
+  load: (writeKey: string, options?: InitOptions) => void
+}
+
+export interface AnalyticsStandalone extends Analytics {
+  _loadOptions?: InitOptions
+  _writeKey?: string
+  _cdn?: string
+}
diff --git a/packages/browser/src/core/analytics/index.ts b/packages/browser/src/core/analytics/index.ts
index 767e7338e..8b88630c8 100644
--- a/packages/browser/src/core/analytics/index.ts
+++ b/packages/browser/src/core/analytics/index.ts
@@ -53,6 +53,7 @@ import {
   isArrayOfStoreType,
 } from '../storage'
 import { PluginFactory } from '../../plugins/remote-loader'
+import { setGlobalAnalytics } from '../../lib/global-analytics-helper'
 
 const deprecationWarning =
   'This is being deprecated and will be not be available in future releases of Analytics JS'
@@ -121,6 +122,11 @@ export interface InitOptions {
    * Array of high entropy Client Hints to request. These may be rejected by the user agent - only required hints should be requested.
    */
   highEntropyValuesClientHints?: HighEntropyHint[]
+  /**
+   * When using the snippet, this is the key that points to the global analytics instance (e.g. window.analytics).
+   * default: analytics
+   */
+  globalAnalyticsKey?: string
 }
 
 /* analytics-classic stubs */
@@ -536,7 +542,7 @@ export class Analytics
 
   noConflict(): Analytics {
     console.warn(deprecationWarning)
-    window.analytics = _analytics ?? this
+    setGlobalAnalytics(_analytics ?? this)
     return this
   }
 
diff --git a/packages/browser/src/core/buffer/snippet.ts b/packages/browser/src/core/buffer/snippet.ts
index 3015dd144..73612b3f6 100644
--- a/packages/browser/src/core/buffer/snippet.ts
+++ b/packages/browser/src/core/buffer/snippet.ts
@@ -3,6 +3,7 @@ import type {
   PreInitMethodName,
   PreInitMethodParams,
 } from '.'
+import { getGlobalAnalytics } from '../../lib/global-analytics-helper'
 
 export function transformSnippetCall([
   methodName,
@@ -29,14 +30,16 @@ type SnippetWindowBufferedMethodCall<
  * A list of the method calls before initialization for snippet users
  * For example, [["track", "foo", {bar: 123}], ["page"], ["on", "ready", function(){..}]
  */
-type SnippetBuffer = SnippetWindowBufferedMethodCall[]
+export type SnippetBuffer = SnippetWindowBufferedMethodCall[]
 
 /**
  * Fetch the buffered method calls from the window object and normalize them.
  * This removes existing buffered calls from the window object.
  */
-export const popSnippetWindowBuffer = (): PreInitMethodCall[] => {
-  const wa = window.analytics
+export const popSnippetWindowBuffer = (
+  buffer: unknown = getGlobalAnalytics()
+): PreInitMethodCall[] => {
+  const wa = buffer
   if (!Array.isArray(wa)) return []
   const buffered = wa.splice(0, wa.length)
   return normalizeSnippetBuffer(buffered)
diff --git a/packages/browser/src/index.ts b/packages/browser/src/index.ts
index abe33d652..625d8e91a 100644
--- a/packages/browser/src/index.ts
+++ b/packages/browser/src/index.ts
@@ -7,5 +7,6 @@ export * from './core/events'
 export * from './core/plugin'
 export * from './core/user'
 
-export type { AnalyticsSnippet } from './browser/standalone-analytics'
+export type { AnalyticsSnippet } from './browser/standalone-interface'
 export type { MiddlewareFunction } from './plugins/middleware'
+export { getGlobalAnalytics } from './lib/global-analytics-helper'
diff --git a/packages/browser/src/lib/__tests__/parse-cdn.test.ts b/packages/browser/src/lib/__tests__/parse-cdn.test.ts
index 2ba92a124..78d449286 100644
--- a/packages/browser/src/lib/__tests__/parse-cdn.test.ts
+++ b/packages/browser/src/lib/__tests__/parse-cdn.test.ts
@@ -51,6 +51,7 @@ it('should return the overridden cdn if window.analytics._cdn is mutated', () =>
   withTag(`
   <script src="https://cdn.segment.com/analytics.js/v1/gA5MBlJXrtZaB5sMMZvCF6czfBcfzNO6/analytics.min.js" />
   `)
+  // @ts-ignore
   ;(window.analytics as any) = {
     _cdn: 'http://foo.cdn.com',
   }
@@ -59,6 +60,7 @@ it('should return the overridden cdn if window.analytics._cdn is mutated', () =>
 
 it('if analytics is not loaded yet, should still return cdn', () => {
   // is this an impossible state?
+  // @ts-ignore
   window.analytics = undefined as any
   withTag(`
   <script src="https://cdn.segment.com/analytics.js/v1/gA5MBlJXrtZaB5sMMZvCF6czfBcfzNO6/analytics.min.js" />
diff --git a/packages/browser/src/lib/global-analytics-helper.ts b/packages/browser/src/lib/global-analytics-helper.ts
new file mode 100644
index 000000000..6ea1be085
--- /dev/null
+++ b/packages/browser/src/lib/global-analytics-helper.ts
@@ -0,0 +1,31 @@
+import { AnalyticsSnippet } from '../browser/standalone-interface'
+
+/**
+ * Stores the global window analytics key
+ */
+let _globalAnalyticsKey = 'analytics'
+
+/**
+ * Gets the global analytics/buffer
+ * @param key name of the window property where the buffer is stored (default: analytics)
+ * @returns AnalyticsSnippet
+ */
+export function getGlobalAnalytics(): AnalyticsSnippet | undefined {
+  return (window as any)[_globalAnalyticsKey]
+}
+
+/**
+ * Replaces the global window key for the analytics/buffer object
+ * @param key key name
+ */
+export function setGlobalAnalyticsKey(key: string) {
+  _globalAnalyticsKey = key
+}
+
+/**
+ * Sets the global analytics object
+ * @param analytics analytics snippet
+ */
+export function setGlobalAnalytics(analytics: AnalyticsSnippet): void {
+  ;(window as any)[_globalAnalyticsKey] = analytics
+}
diff --git a/packages/browser/src/lib/parse-cdn.ts b/packages/browser/src/lib/parse-cdn.ts
index 07ae62bb3..7c9531fca 100644
--- a/packages/browser/src/lib/parse-cdn.ts
+++ b/packages/browser/src/lib/parse-cdn.ts
@@ -1,3 +1,4 @@
+import { getGlobalAnalytics } from './global-analytics-helper'
 import { embeddedWriteKey } from './embedded-write-key'
 
 const analyticsScriptRegex =
@@ -20,13 +21,14 @@ const getCDNUrlFromScriptTag = (): string | undefined => {
 
 let _globalCDN: string | undefined // set globalCDN as in-memory singleton
 const getGlobalCDNUrl = (): string | undefined => {
-  const result = _globalCDN ?? window.analytics?._cdn
+  const result = _globalCDN ?? getGlobalAnalytics()?._cdn
   return result
 }
 
 export const setGlobalCDNUrl = (cdn: string) => {
-  if (window.analytics) {
-    window.analytics._cdn = cdn
+  const globalAnalytics = getGlobalAnalytics()
+  if (globalAnalytics) {
+    globalAnalytics._cdn = cdn
   }
   _globalCDN = cdn
 }
@@ -60,7 +62,7 @@ export const getNextIntegrationsURL = () => {
  * @returns the path to Analytics JS 1.0
  **/
 export function getLegacyAJSPath(): string {
-  const writeKey = embeddedWriteKey() ?? window.analytics._writeKey
+  const writeKey = embeddedWriteKey() ?? getGlobalAnalytics()?._writeKey
 
   const scripts = Array.prototype.slice.call(
     document.querySelectorAll('script')
diff --git a/packages/browser/src/tester/ajs-tester.ts b/packages/browser/src/tester/ajs-tester.ts
index b8d034484..ea317feba 100644
--- a/packages/browser/src/tester/ajs-tester.ts
+++ b/packages/browser/src/tester/ajs-tester.ts
@@ -12,11 +12,13 @@ function makeStub(page: playwright.Page) {
       ...args: Parameters<Analytics['register']>
     ): Promise<SerializedContext> {
       return await page.evaluate((innerArgs) => {
-        // @ts-ignore
-        return window.analytics
-          .register(...innerArgs)
-          .then((ctx) => ctx.toJSON())
-        // @ts-ignore
+        return (
+          // @ts-ignore
+          window.analytics
+            .register(...innerArgs)
+            // @ts-ignore
+            .then((ctx) => ctx.toJSON())
+        )
       }, args)
     },
     async track(
@@ -36,7 +38,7 @@ function makeStub(page: playwright.Page) {
     async page(
       ...args: Parameters<Analytics['page']>
     ): Promise<SerializedContext> {
-      const ctx = await page.evaluate(async (innerArgs) => {
+      const ctx = await page.evaluate((innerArgs) => {
         // @ts-ignore
         return window.analytics.page(...innerArgs).then((ctx) => {
           return ctx.toJSON()
diff --git a/packages/core/src/task/__tests__/task-group.test.ts b/packages/core/src/task/__tests__/task-group.test.ts
new file mode 100644
index 000000000..e484b95ef
--- /dev/null
+++ b/packages/core/src/task/__tests__/task-group.test.ts
@@ -0,0 +1,26 @@
+import { createTaskGroup } from '../task-group'
+
+function sleep(ms: number) {
+  return new Promise((resolve) => setTimeout(resolve, ms))
+}
+
+describe('TaskGroup', () => {
+  it('works with concurrent operations', async () => {
+    const group = createTaskGroup()
+    const a = jest.fn()
+    const b = jest.fn()
+
+    void group.run(async () => {
+      await sleep(100)
+      a()
+    })
+    void group.run(async () => {
+      await sleep(1000)
+      b()
+    })
+
+    await group.done()
+    expect(a).toBeCalled()
+    expect(b).toBeCalled()
+  })
+})