From 65606c093ae1271a3638dab6825ec84d98e4e629 Mon Sep 17 00:00:00 2001
From: Dmitry Gozman <dgozman@gmail.com>
Date: Fri, 9 Jul 2021 16:10:23 -0700
Subject: [PATCH] chore: simplify Registry api (#7451)

---
 src/cli/cli.ts                           |   8 +-
 src/server/browser.ts                    |   2 -
 src/server/browserType.ts                |  16 ++-
 src/server/chromium/chromium.ts          |   5 +-
 src/server/chromium/crPage.ts            |   3 +-
 src/server/firefox/firefox.ts            |   3 +-
 src/server/playwright.ts                 |   3 -
 src/server/trace/viewer/traceViewer.ts   |   3 +-
 src/server/webkit/wkPage.ts              |  11 +-
 src/utils/browserFetcher.ts              |   2 +-
 src/utils/registry.ts                    | 125 ++++++++---------------
 src/utils/utils.ts                       |  36 +++++++
 tests/playwright-test/playwright.spec.ts |   3 +-
 tests/video.spec.ts                      |   3 +-
 14 files changed, 106 insertions(+), 117 deletions(-)

diff --git a/src/cli/cli.ts b/src/cli/cli.ts
index 2ea219f12b..70d4efb8ba 100755
--- a/src/cli/cli.ts
+++ b/src/cli/cli.ts
@@ -31,7 +31,7 @@ import { Page } from '../client/page';
 import { BrowserType } from '../client/browserType';
 import { BrowserContextOptions, LaunchOptions } from '../client/types';
 import { spawn } from 'child_process';
-import { allBrowserNames, BrowserName, Registry } from '../utils/registry';
+import { allBrowserNames, BrowserName, registry } from '../utils/registry';
 import * as utils from '../utils/utils';
 
 const SCRIPTS_DIRECTORY = path.join(__dirname, '..', '..', 'bin');
@@ -126,7 +126,7 @@ program
       try {
         // Install default browsers when invoked without arguments.
         if (!args.length) {
-          await Registry.currentPackageRegistry().installBinaries();
+          await registry.installBinaries();
           return;
         }
         const browserNames: Set<BrowserName> = new Set(args.filter((browser: any) => allBrowserNames.has(browser)));
@@ -139,7 +139,7 @@ program
         if (browserNames.has('chromium') || browserChannels.has('chrome-beta') || browserChannels.has('chrome') || browserChannels.has('msedge') || browserChannels.has('msedge-beta'))
           browserNames.add('ffmpeg');
         if (browserNames.size)
-          await Registry.currentPackageRegistry().installBinaries([...browserNames]);
+          await registry.installBinaries([...browserNames]);
         for (const browserChannel of browserChannels)
           await installBrowserChannel(browserChannel);
       } catch (e) {
@@ -191,7 +191,7 @@ program
     .action(async function(browserTypes) {
       try {
         // TODO: verify the list and print supported browserTypes in the error message.
-        await Registry.currentPackageRegistry().installDeps(browserTypes);
+        await registry.installDeps(browserTypes);
       } catch (e) {
         console.log(`Failed to install browser dependencies\n${e}`);
         process.exit(1);
diff --git a/src/server/browser.ts b/src/server/browser.ts
index 7686762aa7..3472a796cb 100644
--- a/src/server/browser.ts
+++ b/src/server/browser.ts
@@ -21,7 +21,6 @@ import { Download } from './download';
 import { ProxySettings } from './types';
 import { ChildProcess } from 'child_process';
 import { RecentLogsCollector } from '../utils/debugLogger';
-import * as registry from '../utils/registry';
 import { SdkObject } from './instrumentation';
 import { Artifact } from './artifact';
 import { Selectors } from './selectors';
@@ -34,7 +33,6 @@ export interface BrowserProcess {
 }
 
 export type PlaywrightOptions = {
-  registry: registry.Registry,
   rootSdkObject: SdkObject,
   selectors: Selectors,
   loopbackProxyOverride?: () => string,
diff --git a/src/server/browserType.ts b/src/server/browserType.ts
index 6d4c2792fe..f065c43f0d 100644
--- a/src/server/browserType.ts
+++ b/src/server/browserType.ts
@@ -18,7 +18,7 @@ import fs from 'fs';
 import * as os from 'os';
 import path from 'path';
 import { BrowserContext, normalizeProxySettings, validateBrowserContextOptions } from './browserContext';
-import * as registry from '../utils/registry';
+import { registry, BrowserName } from '../utils/registry';
 import { ConnectionTransport, WebSocketTransport } from './transport';
 import { BrowserOptions, Browser, BrowserProcess, PlaywrightOptions } from './browser';
 import { launchProcess, Env, envArrayToObject } from '../utils/processLauncher';
@@ -34,20 +34,18 @@ import { CallMetadata, SdkObject } from './instrumentation';
 const ARTIFACTS_FOLDER = path.join(os.tmpdir(), 'playwright-artifacts-');
 
 export abstract class BrowserType extends SdkObject {
-  private _name: registry.BrowserName;
-  readonly _registry: registry.Registry;
+  private _name: BrowserName;
   readonly _playwrightOptions: PlaywrightOptions;
 
-  constructor(browserName: registry.BrowserName, playwrightOptions: PlaywrightOptions) {
+  constructor(browserName: BrowserName, playwrightOptions: PlaywrightOptions) {
     super(playwrightOptions.rootSdkObject, 'browser-type');
     this.attribution.browserType = this;
     this._playwrightOptions = playwrightOptions;
     this._name = browserName;
-    this._registry = playwrightOptions.registry;
   }
 
   executablePath(channel?: string): string {
-    return this._registry.executablePath(this._name) || '';
+    return registry.executablePath(this._name) || '';
   }
 
   name(): string {
@@ -170,9 +168,9 @@ export abstract class BrowserType extends SdkObject {
     }
 
     // Only validate dependencies for downloadable browsers.
-    const browserName: registry.BrowserName = (options.channel || this._name) as registry.BrowserName;
-    if (!executablePath && this._registry.isSupportedBrowser(browserName))
-      await this._registry.validateHostRequirements(browserName);
+    const browserName: BrowserName = (options.channel || this._name) as BrowserName;
+    if (!executablePath && registry.isSupportedBrowser(browserName))
+      await registry.validateHostRequirements(browserName);
 
     let wsEndpointCallback: ((wsEndpoint: string) => void) | undefined;
     const shouldWaitForWSListening = options.useWebSocket || options.args?.some(a => a.startsWith('--remote-debugging-port'));
diff --git a/src/server/chromium/chromium.ts b/src/server/chromium/chromium.ts
index f32645d3f7..44429c1750 100644
--- a/src/server/chromium/chromium.ts
+++ b/src/server/chromium/chromium.ts
@@ -35,6 +35,7 @@ import { helper } from '../helper';
 import { CallMetadata } from '../instrumentation';
 import { findChromiumChannel } from './findChromiumChannel';
 import http from 'http';
+import { registry } from '../../utils/registry';
 
 const ARTIFACTS_FOLDER = path.join(os.tmpdir(), 'playwright-artifacts-');
 
@@ -52,7 +53,7 @@ export class Chromium extends BrowserType {
     if (channel) {
       let executablePath = undefined;
       if ((channel as any) === 'chromium-with-symbols')
-        executablePath = this._registry.executablePath('chromium-with-symbols');
+        executablePath = registry.executablePath('chromium-with-symbols');
       else
         executablePath = findChromiumChannel(channel);
       assert(executablePath, `unsupported chromium channel "${channel}"`);
@@ -102,7 +103,7 @@ export class Chromium extends BrowserType {
   }
 
   private _createDevTools() {
-    return new CRDevTools(path.join(this._registry.browserDirectory('chromium'), 'devtools-preferences.json'));
+    return new CRDevTools(path.join(registry.browserDirectory('chromium'), 'devtools-preferences.json'));
   }
 
   async _connectToTransport(transport: ConnectionTransport, options: BrowserOptions): Promise<CRBrowser> {
diff --git a/src/server/chromium/crPage.ts b/src/server/chromium/crPage.ts
index 9eb076a707..d669f30000 100644
--- a/src/server/chromium/crPage.ts
+++ b/src/server/chromium/crPage.ts
@@ -40,6 +40,7 @@ import { assert, headersArrayToObject, createGuid, canAccessFile } from '../../u
 import { VideoRecorder } from './videoRecorder';
 import { Progress } from '../progress';
 import { DragManager } from './crDragDrop';
+import { registry } from '../../utils/registry';
 
 
 const UTILITY_WORLD_NAME = '__playwright_utility_world__';
@@ -844,7 +845,7 @@ class FrameSession {
 
   async _createVideoRecorder(screencastId: string, options: types.PageScreencastOptions): Promise<void> {
     assert(!this._screencastId);
-    const ffmpegPath = this._crPage._browserContext._browser.options.registry.executablePath('ffmpeg');
+    const ffmpegPath = registry.executablePath('ffmpeg');
     if (!ffmpegPath)
       throw new Error('ffmpeg executable was not found');
     if (!canAccessFile(ffmpegPath)) {
diff --git a/src/server/firefox/firefox.ts b/src/server/firefox/firefox.ts
index 3a9cf96f5f..933c3ff02c 100644
--- a/src/server/firefox/firefox.ts
+++ b/src/server/firefox/firefox.ts
@@ -26,6 +26,7 @@ import { Env } from '../../utils/processLauncher';
 import { ConnectionTransport } from '../transport';
 import { BrowserOptions, PlaywrightOptions } from '../browser';
 import * as types from '../types';
+import { registry } from '../../utils/registry';
 
 export class Firefox extends BrowserType {
   constructor(playwrightOptions: PlaywrightOptions) {
@@ -36,7 +37,7 @@ export class Firefox extends BrowserType {
     if (channel) {
       let executablePath = undefined;
       if ((channel as any) === 'firefox-beta')
-        executablePath = this._registry.executablePath('firefox-beta');
+        executablePath = registry.executablePath('firefox-beta');
       assert(executablePath, `unsupported firefox channel "${channel}"`);
       assert(fs.existsSync(executablePath), `"${channel}" channel is not installed. Try running 'npx playwright install ${channel}'`);
       return executablePath;
diff --git a/src/server/playwright.ts b/src/server/playwright.ts
index ec0c23264e..d2d6e42a94 100644
--- a/src/server/playwright.ts
+++ b/src/server/playwright.ts
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import path from 'path';
 import { Android } from './android/android';
 import { AdbBackend } from './android/backendAdb';
 import { PlaywrightOptions } from './browser';
@@ -23,7 +22,6 @@ import { Electron } from './electron/electron';
 import { Firefox } from './firefox/firefox';
 import { Selectors } from './selectors';
 import { WebKit } from './webkit/webkit';
-import { Registry } from '../utils/registry';
 import { CallMetadata, createInstrumentation, SdkObject } from './instrumentation';
 import { debugLogger } from '../utils/debugLogger';
 import { PortForwardingServer } from './socksSocket';
@@ -48,7 +46,6 @@ export class Playwright extends SdkObject {
       }
     });
     this.options = {
-      registry: new Registry(path.join(__dirname, '..', '..')),
       rootSdkObject: this,
       selectors: new Selectors(),
     };
diff --git a/src/server/trace/viewer/traceViewer.ts b/src/server/trace/viewer/traceViewer.ts
index c12119f1d1..efbd6df3a3 100644
--- a/src/server/trace/viewer/traceViewer.ts
+++ b/src/server/trace/viewer/traceViewer.ts
@@ -29,7 +29,7 @@ import { canAccessFile, isUnderTest } from '../../../utils/utils';
 import { internalCallMetadata } from '../../instrumentation';
 import { ProgressController } from '../../progress';
 import { BrowserContext } from '../../browserContext';
-import { Registry } from '../../../utils/registry';
+import { registry } from '../../../utils/registry';
 import { findChromiumChannel } from '../../chromium/findChromiumChannel';
 import { installAppIcon } from '../../chromium/crApp';
 
@@ -140,7 +140,6 @@ export class TraceViewer {
     // Null means no installation and no channels found.
     let channel = null;
     if (traceViewerBrowser === 'chromium') {
-      const registry = Registry.currentPackageRegistry();
       if (canAccessFile(registry.executablePath('chromium')!)) {
         // This means we have a browser downloaded.
         channel = undefined;
diff --git a/src/server/webkit/wkPage.ts b/src/server/webkit/wkPage.ts
index 7373307fab..15771b6011 100644
--- a/src/server/webkit/wkPage.ts
+++ b/src/server/webkit/wkPage.ts
@@ -19,8 +19,7 @@ import * as jpeg from 'jpeg-js';
 import path from 'path';
 import * as png from 'pngjs';
 import { splitErrorMessage } from '../../utils/stackTrace';
-import { hostPlatform } from '../../utils/registry';
-import { assert, createGuid, debugAssert, headersArrayToObject, headersObjectToArray } from '../../utils/utils';
+import { assert, createGuid, debugAssert, headersArrayToObject, headersObjectToArray, hostPlatform } from '../../utils/utils';
 import * as accessibility from '../accessibility';
 import * as dialog from '../dialog';
 import * as dom from '../dom';
@@ -769,14 +768,13 @@ export class WKPage implements PageDelegate {
 
   private _toolbarHeight(): number {
     if (this._page._browserContext._browser?.options.headful)
-      return hostPlatform.startsWith('10.15') ? 55 : 59;
+      return hostPlatform === 'mac10.15' ? 55 : 59;
     return 0;
   }
 
   private async _startVideo(options: types.PageScreencastOptions): Promise<void> {
     assert(!this._recordingVideoFile);
-    const START_VIDEO_PROTOCOL_COMMAND = hostPlatform === 'mac10.14' ? 'Screencast.start' : 'Screencast.startVideo';
-    const { screencastId } = await this._pageProxySession.send(START_VIDEO_PROTOCOL_COMMAND as any, {
+    const { screencastId } = await this._pageProxySession.send('Screencast.startVideo', {
       file: options.outputFile,
       width: options.width,
       height: options.height,
@@ -789,8 +787,7 @@ export class WKPage implements PageDelegate {
   private async _stopVideo(): Promise<void> {
     if (!this._recordingVideoFile)
       return;
-    const STOP_VIDEO_PROTOCOL_COMMAND = hostPlatform === 'mac10.14' ? 'Screencast.stop' : 'Screencast.stopVideo';
-    await this._pageProxySession.sendMayFail(STOP_VIDEO_PROTOCOL_COMMAND as any);
+    await this._pageProxySession.sendMayFail('Screencast.stopVideo');
     this._recordingVideoFile = null;
   }
 
diff --git a/src/utils/browserFetcher.ts b/src/utils/browserFetcher.ts
index 8b2fc4b211..254f5d486f 100644
--- a/src/utils/browserFetcher.ts
+++ b/src/utils/browserFetcher.ts
@@ -51,7 +51,7 @@ export async function downloadBrowserWithProgressBar(title: string, browserDirec
   }
 
   const url = downloadURL;
-  const zipPath = path.join(os.tmpdir(), `${downloadFileName}.zip`);
+  const zipPath = path.join(os.tmpdir(), downloadFileName);
   try {
     for (let attempt = 1, N = 3; attempt <= N; ++attempt) {
       debugLogger.log('install', `downloading ${progressBarName} - attempt #${attempt}`);
diff --git a/src/utils/registry.ts b/src/utils/registry.ts
index 61bfb7f95a..606867955f 100644
--- a/src/utils/registry.ts
+++ b/src/utils/registry.ts
@@ -20,8 +20,8 @@ import path from 'path';
 import * as util from 'util';
 import * as fs from 'fs';
 import lockfile from 'proper-lockfile';
-import { getUbuntuVersion, getUbuntuVersionSync } from './ubuntuVersion';
-import { assert, getFromENV, getAsBooleanFromENV, calculateSha1, removeFolders, existsAsync } from './utils';
+import { getUbuntuVersion } from './ubuntuVersion';
+import { assert, getFromENV, getAsBooleanFromENV, calculateSha1, removeFolders, existsAsync, hostPlatform } from './utils';
 import { installDependenciesLinux, installDependenciesWindows, validateDependenciesLinux, validateDependenciesWindows } from './dependencies';
 import { downloadBrowserWithProgressBar, logPolitely } from './browserFetcher';
 
@@ -30,14 +30,6 @@ export const allBrowserNames: Set<BrowserName> = new Set(['chromium', 'chromium-
 
 const PACKAGE_PATH = path.join(__dirname, '..', '..');
 
-type BrowserPlatform = 'win32'|'win64'|'mac10.13'|'mac10.14'|'mac10.15'|'mac11'|'mac11-arm64'|'ubuntu18.04'|'ubuntu20.04';
-type BrowserDescriptor = {
-  name: BrowserName,
-  revision: string,
-  installByDefault: boolean,
-  browserDirectory: string,
-};
-
 const EXECUTABLE_PATHS = {
   'chromium': {
     'ubuntu18.04': ['chrome-linux', 'chrome'],
@@ -176,41 +168,7 @@ const DOWNLOAD_URLS = {
   },
 };
 
-export const hostPlatform = ((): BrowserPlatform => {
-  const platform = os.platform();
-  if (platform === 'darwin') {
-    const ver = os.release().split('.').map((a: string) => parseInt(a, 10));
-    let macVersion = '';
-    if (ver[0] < 18) {
-      // Everything before 10.14 is considered 10.13.
-      macVersion = 'mac10.13';
-    } else if (ver[0] === 18) {
-      macVersion = 'mac10.14';
-    } else if (ver[0] === 19) {
-      macVersion = 'mac10.15';
-    } else {
-      // ver[0] >= 20
-      const LAST_STABLE_MAC_MAJOR_VERSION = 11;
-      // Best-effort support for MacOS beta versions.
-      macVersion = 'mac' + Math.min(ver[0] - 9, LAST_STABLE_MAC_MAJOR_VERSION);
-      // BigSur is the first version that might run on Apple Silicon.
-      if (os.cpus().some(cpu => cpu.model.includes('Apple')))
-        macVersion += '-arm64';
-    }
-    return macVersion as BrowserPlatform;
-  }
-  if (platform === 'linux') {
-    const ubuntuVersion = getUbuntuVersionSync();
-    if (parseInt(ubuntuVersion, 10) <= 19)
-      return 'ubuntu18.04';
-    return 'ubuntu20.04';
-  }
-  if (platform === 'win32')
-    return os.arch() === 'x64' ? 'win64' : 'win32';
-  return platform as BrowserPlatform;
-})();
-
-export const registryDirectory = (() => {
+const registryDirectory = (() => {
   let result: string;
 
   const envDefined = getFromENV('PLAYWRIGHT_BROWSERS_PATH');
@@ -242,7 +200,7 @@ export const registryDirectory = (() => {
   return result;
 })();
 
-export function isBrowserDirectory(browserDirectory: string): boolean {
+function isBrowserDirectory(browserDirectory: string): boolean {
   const baseName = path.basename(browserDirectory);
   for (const browserName of allBrowserNames) {
     if (baseName.startsWith(browserName + '-'))
@@ -251,38 +209,40 @@ export function isBrowserDirectory(browserDirectory: string): boolean {
   return false;
 }
 
-let currentPackageRegistry: Registry | undefined = undefined;
+type BrowserDescriptor = {
+  name: BrowserName,
+  revision: string,
+  installByDefault: boolean,
+  browserDirectory: string,
+};
+
+function readDescriptors(packagePath: string) {
+  const browsersJSON = require(path.join(packagePath, 'browsers.json'));
+  return (browsersJSON['browsers'] as any[]).map(obj => {
+    const name = obj.name;
+    const revisionOverride = (obj.revisionOverrides || {})[hostPlatform];
+    const revision = revisionOverride || obj.revision;
+    const browserDirectoryPrefix = revisionOverride ? `${name}_${hostPlatform}_special` : `${name}`;
+    const descriptor: BrowserDescriptor = {
+      name,
+      revision,
+      installByDefault: !!obj.installByDefault,
+      // Method `isBrowserDirectory` determines directory to be browser iff
+      // it starts with some browser name followed by '-'. Some browser names
+      // are prefixes of others, e.g. 'webkit' is a prefix of `webkit-technology-preview`.
+      // To avoid older registries erroneously removing 'webkit-technology-preview', we have to
+      // ensure that browser folders to never include dashes inside.
+      browserDirectory: browserDirectoryPrefix.replace(/-/g, '_') + '-' + revision,
+    };
+    return descriptor;
+  });
+}
 
 export class Registry {
   private _descriptors: BrowserDescriptor[];
 
-  static currentPackageRegistry() {
-    if (!currentPackageRegistry)
-      currentPackageRegistry = new Registry(PACKAGE_PATH);
-    return currentPackageRegistry;
-  }
-
   constructor(packagePath: string) {
-    // require() needs to be used there otherwise it breaks on Vercel serverless
-    // functions. See https://github.com/microsoft/playwright/pull/6186
-    const browsersJSON = require(path.join(packagePath, 'browsers.json'));
-    this._descriptors = browsersJSON['browsers'].map((obj: any) => {
-      const name = obj.name;
-      const revisionOverride = (obj.revisionOverrides || {})[hostPlatform];
-      const revision = revisionOverride || obj.revision;
-      const browserDirectoryPrefix = revisionOverride ? `${name}_${hostPlatform}_special` : `${name}`;
-      return {
-        name,
-        revision,
-        installByDefault: !!obj.installByDefault,
-        // Method `isBrowserDirectory` determines directory to be browser iff
-        // it starts with some browser name followed by '-'. Some browser names
-        // are prefixes of others, e.g. 'webkit' is a prefix of `webkit-technology-preview`.
-        // To avoid older registries erroneously removing 'webkit-technology-preview', we have to
-        // ensure that browser folders to never include dashes inside.
-        browserDirectory: browserDirectoryPrefix.replace(/-/g, '_') + '-' + revision,
-      };
-    });
+    this._descriptors = readDescriptors(packagePath);
   }
 
   browserDirectory(browserName: BrowserName): string {
@@ -291,10 +251,10 @@ export class Registry {
     return path.join(registryDirectory, browser.browserDirectory);
   }
 
-  private _revision(browserName: BrowserName): number {
+  private _revision(browserName: BrowserName): string {
     const browser = this._descriptors.find(browser => browser.name === browserName);
     assert(browser, `ERROR: Playwright does not support ${browserName}`);
-    return parseInt(browser.revision, 10);
+    return browser.revision;
   }
 
   executablePath(browserName: BrowserName): string | undefined {
@@ -430,7 +390,7 @@ export class Registry {
         const revision = this._revision(browserName);
         const browserDirectory = this.browserDirectory(browserName);
         const title = `${browserName} v${revision}`;
-        const downloadFileName = `playwright-download-${browserName}-${hostPlatform}-${revision}`;
+        const downloadFileName = `playwright-download-${browserName}-${hostPlatform}-${revision}.zip`;
         await downloadBrowserWithProgressBar(title, browserDirectory, this.executablePath(browserName)!, this._downloadURL(browserName), downloadFileName).catch(e => {
           throw new Error(`Failed to download ${title}, caused by\n${e.stack}`);
         });
@@ -449,12 +409,13 @@ export class Registry {
       let linkTarget = '';
       try {
         linkTarget = (await fs.promises.readFile(linkPath)).toString();
-        const linkRegistry = new Registry(linkTarget);
+        const descriptors = readDescriptors(linkTarget);
         for (const browserName of allBrowserNames) {
-          if (!linkRegistry.isSupportedBrowser(browserName))
+          const descriptor = descriptors.find(d => d.name === browserName);
+          if (!descriptor)
             continue;
-          const usedBrowserPath = linkRegistry.browserDirectory(browserName);
-          const browserRevision = linkRegistry._revision(browserName);
+          const usedBrowserPath = path.join(registryDirectory, descriptor.browserDirectory);
+          const browserRevision = parseInt(descriptor.revision, 10);
           // Old browser installations don't have marker file.
           const shouldHaveMarkerFile = (browserName === 'chromium' && browserRevision >= 786218) ||
               (browserName === 'firefox' && browserRevision >= 1128) ||
@@ -493,5 +454,7 @@ export async function installDefaultBrowsersForNpmInstall() {
     logPolitely('Skipping browsers download because `PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD` env variable is set');
     return false;
   }
-  await Registry.currentPackageRegistry().installBinaries();
+  await registry.installBinaries();
 }
+
+export const registry = new Registry(PACKAGE_PATH);
diff --git a/src/utils/utils.ts b/src/utils/utils.ts
index ae0eb6c1f1..c9d24ef403 100644
--- a/src/utils/utils.ts
+++ b/src/utils/utils.ts
@@ -22,6 +22,7 @@ import os from 'os';
 import { spawn } from 'child_process';
 import { getProxyForUrl } from 'proxy-from-env';
 import * as URL from 'url';
+import { getUbuntuVersionSync } from './ubuntuVersion';
 
 // `https-proxy-agent` v5 is written in TypeScript and exposes generated types.
 // However, as of June 2020, its types are generated with tsconfig that enables
@@ -321,3 +322,38 @@ export function constructURLBasedOnBaseURL(baseURL: string | undefined, givenURL
     return givenURL;
   }
 }
+
+export type HostPlatform = 'win32'|'win64'|'mac10.13'|'mac10.14'|'mac10.15'|'mac11'|'mac11-arm64'|'ubuntu18.04'|'ubuntu20.04';
+export const hostPlatform = ((): HostPlatform => {
+  const platform = os.platform();
+  if (platform === 'darwin') {
+    const ver = os.release().split('.').map((a: string) => parseInt(a, 10));
+    let macVersion = '';
+    if (ver[0] < 18) {
+      // Everything before 10.14 is considered 10.13.
+      macVersion = 'mac10.13';
+    } else if (ver[0] === 18) {
+      macVersion = 'mac10.14';
+    } else if (ver[0] === 19) {
+      macVersion = 'mac10.15';
+    } else {
+      // ver[0] >= 20
+      const LAST_STABLE_MAC_MAJOR_VERSION = 11;
+      // Best-effort support for MacOS beta versions.
+      macVersion = 'mac' + Math.min(ver[0] - 9, LAST_STABLE_MAC_MAJOR_VERSION);
+      // BigSur is the first version that might run on Apple Silicon.
+      if (os.cpus().some(cpu => cpu.model.includes('Apple')))
+        macVersion += '-arm64';
+    }
+    return macVersion as HostPlatform;
+  }
+  if (platform === 'linux') {
+    const ubuntuVersion = getUbuntuVersionSync();
+    if (parseInt(ubuntuVersion, 10) <= 19)
+      return 'ubuntu18.04';
+    return 'ubuntu20.04';
+  }
+  if (platform === 'win32')
+    return os.arch() === 'x64' ? 'win64' : 'win32';
+  return platform as HostPlatform;
+})();
diff --git a/tests/playwright-test/playwright.spec.ts b/tests/playwright-test/playwright.spec.ts
index aaea69915c..9e63e7b236 100644
--- a/tests/playwright-test/playwright.spec.ts
+++ b/tests/playwright-test/playwright.spec.ts
@@ -18,9 +18,8 @@ import { test, expect, stripAscii } from './playwright-test-fixtures';
 import fs from 'fs';
 import path from 'path';
 import { spawnSync } from 'child_process';
-import { Registry } from '../../src/utils/registry';
+import { registry } from '../../src/utils/registry';
 
-const registry = new Registry(path.join(__dirname, '..', '..'));
 const ffmpeg = registry.executablePath('ffmpeg') || '';
 
 export class VideoPlayer {
diff --git a/tests/video.spec.ts b/tests/video.spec.ts
index 22a967b5b5..892cf512be 100644
--- a/tests/video.spec.ts
+++ b/tests/video.spec.ts
@@ -19,9 +19,8 @@ import fs from 'fs';
 import path from 'path';
 import { spawnSync } from 'child_process';
 import { PNG } from 'pngjs';
-import { Registry } from '../src/utils/registry';
+import { registry } from '../src/utils/registry';
 
-const registry = new Registry(path.join(__dirname, '..'));
 const ffmpeg = registry.executablePath('ffmpeg') || '';
 
 export class VideoPlayer {