fix: Improve Big Sur browser detection performance (#17807)

circle.yml

@@ -8,7 +8,7 @@ macBuildFilters: &macBuildFilters
     branches:
       only:
         - develop
-        - tgriesser/fix/mac-build
+        - issue-17773-slow-browser-detection
 
 defaults: &defaults
   parallelism: 1
@@ -1489,7 +1489,7 @@ jobs:
       - run:
           name: Check current branch to persist artifacts
           command: |
-            if [[ "$CIRCLE_BRANCH" != "develop" ]]; then
+            if [[ "$CIRCLE_BRANCH" != "develop" && "$CIRCLE_BRANCH" != "issue-17773-slow-browser-detection" ]]; then
               echo "Not uploading artifacts or posting install comment for this branch."
               circleci-agent step halt
             fi

packages/launcher/lib/darwin/detection-workaround.js

@@ -0,0 +1,6 @@
+const { detect } = require('../detect')
+
+detect(undefined, false).then((browsers) => {
+  // eslint-disable-next-line no-console
+  console.log(JSON.stringify(browsers, null, 2))
+})

packages/launcher/lib/darwin/util.ts

@@ -2,9 +2,13 @@ import { log } from '../log'
 import { notInstalledErr } from '../errors'
 import { prop, tap } from 'ramda'
 import { utils } from '../utils'
-import fs from 'fs-extra'
+import * as fs from 'fs-extra'
+import * as os from 'os'
 import * as path from 'path'
 import * as plist from 'plist'
+import * as semver from 'semver'
+import { FoundBrowser } from '../types'
+import * as findSystemNode from '@packages/server/lib/util/find_system_node'
 
 /** parses Info.plist file from given application and returns a property */
 export function parsePlist (p: string, property: string): Promise<string> {
@@ -96,3 +100,20 @@ export function findApp ({ appName, executable, appId, versionProperty }: FindAp
 
   return tryMdFind().catch(tryFullApplicationFind)
 }
+
+export function needsDarwinWorkaround (): boolean {
+  return os.platform() === 'darwin' && semver.gte(os.release(), '20.0.0')
+}
+
+export async function darwinDetectionWorkaround (): Promise<FoundBrowser[]> {
+  const nodePath = await findSystemNode.findNodeInFullPath()
+  let args = ['./detection-workaround.js']
+
+  if (process.env.CYPRESS_INTERNAL_ENV === 'development') {
+    args = ['-r', '@packages/ts/register.js'].concat(args)
+  }
+
+  const { stdout } = await utils.execa(nodePath, args, { cwd: __dirname })
+
+  return JSON.parse(stdout)
+}

packages/launcher/lib/detect.ts

@@ -4,6 +4,7 @@ import os from 'os'
 import { flatten, merge, pick, props, tap, uniqBy } from 'ramda'
 import { browsers } from './browsers'
 import * as darwinHelper from './darwin'
+import { needsDarwinWorkaround, darwinDetectionWorkaround } from './darwin/util'
 import { notDetectedAtPathErr } from './errors'
 import * as linuxHelper from './linux'
 import { log } from './log'
@@ -137,13 +138,44 @@ function checkOneBrowser (browser: Browser): Promise<boolean | FoundBrowser> {
 }
 
 /** returns list of detected browsers */
-export const detect = (goalBrowsers?: Browser[]): Bluebird<FoundBrowser[]> => {
+export const detect = (goalBrowsers?: Browser[], useDarwinWorkaround = true): Bluebird<FoundBrowser[]> => {
   // we can detect same browser under different aliases
   // tell them apart by the name and the version property
   if (!goalBrowsers) {
     goalBrowsers = browsers
   }
 
+  // BigSur (darwin 20.x) and Electron 12+ cause huge performance issues when
+  // spawning child processes, which is the way we find browsers via execa.
+  // The performance cost is multiplied by the number of binary variants of
+  // each browser plus any fallback lookups we do.
+  // The workaround gets around this by breaking out of the bundled Electron
+  // Node.js and using the user's Node.js if possible. It only pays the cost
+  // of spawning a single child process instead of multiple. If this fails,
+  // we fall back to to the slower, default method
+  // https://github.com/cypress-io/cypress/issues/17773
+  if (useDarwinWorkaround && needsDarwinWorkaround()) {
+    log('using darwin detection workaround')
+    if (log.enabled) {
+      // eslint-disable-next-line no-console
+      console.time('time taken detecting browsers (darwin workaround)')
+    }
+
+    return Bluebird.resolve(darwinDetectionWorkaround())
+    .catch((err) => {
+      log('darwin workaround failed, falling back to normal detection')
+      log(err.stack)
+
+      return detect(goalBrowsers, false)
+    })
+    .finally(() => {
+      if (log.enabled) {
+        // eslint-disable-next-line no-console
+        console.timeEnd('time taken detecting browsers (darwin workaround)')
+      }
+    })
+  }
+
   const removeDuplicates = uniqBy((browser: FoundBrowser) => {
     return props(['name', 'version'], browser)
   })

packages/launcher/lib/windows/index.ts

@@ -1,4 +1,4 @@
-import fse from 'fs-extra'
+import * as fse from 'fs-extra'
 import os from 'os'
 import { join, normalize, win32 } from 'path'
 import { tap, trim, prop } from 'ramda'

packages/launcher/package.json

@@ -19,7 +19,8 @@
     "fs-extra": "8.1.0",
     "lodash": "4.17.21",
     "plist": "3.0.1",
-    "ramda": "0.27.1"
+    "ramda": "0.27.1",
+    "semver": "7.3.5"
   },
   "devDependencies": {
     "@packages/ts": "0.0.0-development",
@@ -36,4 +37,4 @@
     "lib"
   ],
   "types": "index.ts"
-}
+}

packages/launcher/test/unit/detect_spec.ts

@@ -4,9 +4,10 @@ import { goalBrowsers } from '../fixtures'
 import { expect } from 'chai'
 import { utils } from '../../lib/utils'
 import sinon, { SinonStub } from 'sinon'
-const os = require('os')
+import os from 'os'
 import { log } from '../log'
 import { project } from 'ramda'
+import * as darwinUtil from '../../lib/darwin/util'
 
 const isWindows = () => {
   return os.platform() === 'win32'
@@ -168,4 +169,25 @@ describe('browser detection', () => {
       .and.contain('Firefox newer than or equal to 86')
     })
   })
+
+  // https://github.com/cypress-io/cypress/issues/17773
+  context('darwin performance workaround', () => {
+    let browsers
+
+    beforeEach(() => {
+      sinon.stub(os, 'platform').returns('darwin')
+      sinon.stub(os, 'release').returns('20.0.0')
+
+      browsers = []
+
+      sinon.stub(darwinUtil, 'darwinDetectionWorkaround').resolves(browsers)
+    })
+
+    it('uses workaround when on darwin 20.0.0+', async () => {
+      const result = await detect()
+
+      expect(darwinUtil.darwinDetectionWorkaround).to.be.called
+      expect(result).to.equal(browsers)
+    })
+  })
 })

packages/launcher/test/unit/linux_spec.ts

@@ -18,6 +18,9 @@ describe('linux browser detection', () => {
     sinon.restore()
     execa = sinon.stub(utils, 'getOutput')
 
+    sinon.stub(os, 'platform').returns('linux')
+    sinon.stub(os, 'release').returns('1.0.0')
+
     execa.withArgs('test-browser', ['--version'])
     .resolves({ stdout: 'test-browser v100.1.2.3' })
 
@@ -50,7 +53,6 @@ describe('linux browser detection', () => {
     execa.withArgs('chromium', ['--version'])
     .resolves({ stdout: 'Chromium 64.2.3 snap' })
 
-    sinon.stub(os, 'platform').returns('linux')
     sinon.stub(os, 'homedir').returns('/home/foo')
 
     const checkBrowser = ([browser]) => {

packages/server/lib/util/find_system_node.js

@@ -79,5 +79,6 @@ function findNodePathAndVersion () {
 }
 
 module.exports = {
+  findNodeInFullPath,
   findNodePathAndVersion,
 }

yarn.lock

@@ -34688,7 +34688,7 @@ semver@7.3.4:
   dependencies:
     lru-cache "^6.0.0"
 
-semver@^7.0.0, semver@^7.1.1, semver@^7.1.2, semver@^7.2.1, semver@^7.3.2, semver@^7.3.4, semver@^7.3.5:
+semver@7.3.5, semver@^7.0.0, semver@^7.1.1, semver@^7.1.2, semver@^7.2.1, semver@^7.3.2, semver@^7.3.4, semver@^7.3.5:
   version "7.3.5"
   resolved "https://registry.yarnpkg.com/semver/-/semver-7.3.5.tgz#0b621c879348d8998e4b0e4be94b3f12e6018ef7"
   integrity sha512-PoeGJYh8HK4BTO/a9Tf6ZG3veo/A7ZVsYrSA6J8ny9nb3B1VrpkuN+z9OE5wfE5p6H4LchYZsegiQgbJD94ZFQ==