chore: introduce manual promise race (#21358)

Fixes https://github.com/microsoft/playwright/issues/21345

packages/playwright-core/src/client/browserContext.ts

@@ -149,7 +149,7 @@ export class BrowserContext extends ChannelOwner<channels.BrowserContextChannel>
     if (page)
       page.emit(Events.Page.RequestFinished, request);
     if (response)
-      response._finishedPromise.resolve();
+      response._finishedPromise.resolve(null);
   }
 
   async _onRoute(route: network.Route) {

packages/playwright-core/src/client/network.ts

@@ -23,7 +23,7 @@ import type { Headers, RemoteAddr, SecurityDetails, WaitForEventOptions } from '
 import fs from 'fs';
 import { mime } from '../utilsBundle';
 import { assert, isString, headersObjectToArray, isRegExp } from '../utils';
-import { ManualPromise } from '../utils/manualPromise';
+import { ManualPromise, ScopedRace } from '../utils/manualPromise';
 import { Events } from './events';
 import type { Page } from './page';
 import { Waiter } from './waiter';
@@ -33,7 +33,6 @@ import { urlMatches } from '../utils/network';
 import { MultiMap } from '../utils/multimap';
 import { APIResponse } from './fetch';
 import type { Serializable } from '../../types/structs';
-import { kBrowserOrContextClosedError } from '../common/errors';
 
 export type NetworkCookie = {
   name: string,
@@ -271,8 +270,8 @@ export class Request extends ChannelOwner<channels.RequestChannel> implements ap
     return this._fallbackOverrides;
   }
 
-  _targetClosedPromise(): Promise<void> {
-    return this.serviceWorker()?._closedPromise || this.frame()._page?._closedOrCrashedPromise || new Promise(() => {});
+  _targetClosedRace(): ScopedRace {
+    return this.serviceWorker()?._closedRace || this.frame()._page?._closedOrCrashedRace || new ScopedRace();
   }
 }
 
@@ -295,10 +294,7 @@ export class Route extends ChannelOwner<channels.RouteChannel> implements api.Ro
     // When page closes or crashes, we catch any potential rejects from this Route.
     // Note that page could be missing when routing popup's initial request that
     // does not have a Page initialized just yet.
-    return Promise.race([
-      promise,
-      this.request()._targetClosedPromise(),
-    ]);
+    return this.request()._targetClosedRace().safeRace(promise);
   }
 
   _startHandling(): Promise<boolean> {
@@ -452,7 +448,7 @@ export class Response extends ChannelOwner<channels.ResponseChannel> implements
   private _provisionalHeaders: RawHeaders;
   private _actualHeadersPromise: Promise<RawHeaders> | undefined;
   private _request: Request;
-  readonly _finishedPromise = new ManualPromise<void>();
+  readonly _finishedPromise = new ManualPromise<null>();
 
   static from(response: channels.ResponseChannel): Response {
     return (response as any)._object;
@@ -523,12 +519,7 @@ export class Response extends ChannelOwner<channels.ResponseChannel> implements
   }
 
   async finished(): Promise<null> {
-    return Promise.race([
-      this._finishedPromise.then(() => null),
-      this.request()._targetClosedPromise().then(() => {
-        throw new Error(kBrowserOrContextClosedError);
-      }),
-    ]);
+    return this.request()._targetClosedRace().race(this._finishedPromise);
   }
 
   async body(): Promise<Buffer> {

packages/playwright-core/src/client/page.ts

@@ -19,12 +19,12 @@ import fs from 'fs';
 import path from 'path';
 import type * as structs from '../../types/structs';
 import type * as api from '../../types/types';
-import { isSafeCloseError } from '../common/errors';
+import { isSafeCloseError, kBrowserOrContextClosedError } from '../common/errors';
 import { urlMatches } from '../utils/network';
 import { TimeoutSettings } from '../common/timeoutSettings';
 import type * as channels from '@protocol/channels';
 import { parseError, serializeError } from '../protocol/serializers';
-import { assert, headersObjectToArray, isObject, isRegExp, isString } from '../utils';
+import { assert, headersObjectToArray, isObject, isRegExp, isString, ScopedRace } from '../utils';
 import { mkdirIfNeeded } from '../utils/fileUtils';
 import { Accessibility } from './accessibility';
 import { Artifact } from './artifact';
@@ -80,7 +80,7 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
   private _frames = new Set<Frame>();
   _workers = new Set<Worker>();
   private _closed = false;
-  _closedOrCrashedPromise: Promise<void>;
+  readonly _closedOrCrashedRace = new ScopedRace();
   private _viewportSize: Size | null;
   private _routes: RouteHandler[] = [];
 
@@ -153,10 +153,8 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
 
     this.coverage = new Coverage(this._channel);
 
-    this._closedOrCrashedPromise = Promise.race([
-      new Promise<void>(f => this.once(Events.Page.Close, f)),
-      new Promise<void>(f => this.once(Events.Page.Crash, f)),
-    ]);
+    this.once(Events.Page.Close, () => this._closedOrCrashedRace.scopeClosed(new Error(kBrowserOrContextClosedError)));
+    this.once(Events.Page.Crash, () => this._closedOrCrashedRace.scopeClosed(new Error(kBrowserOrContextClosedError)));
 
     this._setEventToSubscriptionMapping(new Map<string, channels.PageUpdateSubscriptionParams['event']>([
       [Events.Page.Request, 'request'],
@@ -693,10 +691,7 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
   async pause() {
     if (require('inspector').url())
       return;
-    await Promise.race([
-      this.context()._channel.pause(),
-      this._closedOrCrashedPromise
-    ]);
+    await this._closedOrCrashedRace.safeRace(this.context()._channel.pause());
   }
 
   async pdf(options: PDFOptions = {}): Promise<Buffer> {

packages/playwright-core/src/client/video.ts

@@ -18,22 +18,20 @@ import type { Page } from './page';
 import type * as api from '../../types/types';
 import type { Artifact } from './artifact';
 import type { Connection } from './connection';
+import { ManualPromise } from '../utils';
 
 export class Video implements api.Video {
   private _artifact: Promise<Artifact | null> | null = null;
-  private _artifactCallback = (artifact: Artifact) => {};
+  private _artifactReadyPromise = new ManualPromise<Artifact>();
   private _isRemote = false;
 
   constructor(page: Page, connection: Connection) {
     this._isRemote = connection.isRemote();
-    this._artifact = Promise.race([
-      new Promise<Artifact>(f => this._artifactCallback = f),
-      page._closedOrCrashedPromise.then(() => null),
-    ]);
+    this._artifact = page._closedOrCrashedRace.safeRace(this._artifactReadyPromise);
   }
 
   _artifactReady(artifact: Artifact) {
-    this._artifactCallback(artifact);
+    this._artifactReadyPromise.resolve(artifact);
   }
 
   async path(): Promise<string> {

packages/playwright-core/src/client/worker.ts

@@ -22,11 +22,13 @@ import type { Page } from './page';
 import type { BrowserContext } from './browserContext';
 import type * as api from '../../types/types';
 import type * as structs from '../../types/structs';
+import { ScopedRace } from '../utils';
+import { kBrowserOrContextClosedError } from '../common/errors';
 
 export class Worker extends ChannelOwner<channels.WorkerChannel> implements api.Worker {
   _page: Page | undefined;  // Set for web workers.
   _context: BrowserContext | undefined;  // Set for service workers.
-  _closedPromise: Promise<void>;
+  readonly _closedRace = new ScopedRace();
 
   static from(worker: channels.WorkerChannel): Worker {
     return (worker as any)._object;
@@ -41,7 +43,7 @@ export class Worker extends ChannelOwner<channels.WorkerChannel> implements api.
         this._context._serviceWorkers.delete(this);
       this.emit(Events.Worker.Close, this);
     });
-    this._closedPromise = new Promise(f => this.once(Events.Worker.Close, f));
+    this.once(Events.Worker.Close, () => this._closedRace.scopeClosed(new Error(kBrowserOrContextClosedError)));
   }
 
   url(): string {

packages/playwright-core/src/server/javascript.ts

@@ -19,7 +19,7 @@ import * as utilityScriptSource from '../generated/utilityScriptSource';
 import { serializeAsCallArgument } from './isomorphic/utilityScriptSerializers';
 import { type UtilityScript } from './injected/utilityScript';
 import { SdkObject } from './instrumentation';
-import { ManualPromise } from '../utils/manualPromise';
+import { ScopedRace } from '../utils/manualPromise';
 
 export type ObjectId = string;
 export type RemoteObject = {
@@ -62,7 +62,7 @@ export interface ExecutionContextDelegate {
 export class ExecutionContext extends SdkObject {
   private _delegate: ExecutionContextDelegate;
   private _utilityScriptPromise: Promise<JSHandle> | undefined;
-  private _destroyedPromise = new ManualPromise<Error>();
+  private _contextDestroyedRace = new ScopedRace();
 
   constructor(parent: SdkObject, delegate: ExecutionContextDelegate) {
     super(parent, 'execution-context');
@@ -70,14 +70,11 @@ export class ExecutionContext extends SdkObject {
   }
 
   contextDestroyed(error: Error) {
-    this._destroyedPromise.resolve(error);
+    this._contextDestroyedRace.scopeClosed(error);
   }
 
-  _raceAgainstContextDestroyed<T>(promise: Promise<T>): Promise<T> {
-    return Promise.race([
-      this._destroyedPromise.then(e => { throw e; }),
-      promise,
-    ]);
+  async _raceAgainstContextDestroyed<T>(promise: Promise<T>): Promise<T> {
+    return this._contextDestroyedRace.race(promise);
   }
 
   rawEvaluateJSON(expression: string): Promise<any> {

packages/playwright-core/src/utils/manualPromise.ts

@@ -53,3 +53,37 @@ export class ManualPromise<T = void> extends Promise<T> {
     return 'ManualPromise';
   }
 }
+
+export class ScopedRace {
+  private _terminateError: Error | undefined;
+  private _terminatePromises = new Set<ManualPromise<Error>>();
+
+  scopeClosed(error: Error) {
+    this._terminateError = error;
+    for (const p of this._terminatePromises)
+      p.resolve(error);
+  }
+
+  async race<T>(promise: Promise<T>): Promise<T> {
+    return this._race([promise], false) as Promise<T>;
+  }
+
+  async safeRace<T>(promise: Promise<T>, defaultValue?: T): Promise<T> {
+    return this._race([promise], true, defaultValue);
+  }
+
+  private async _race(promises: Promise<any>[], safe: boolean, defaultValue?: any): Promise<any> {
+    const terminatePromise = new ManualPromise<Error>();
+    if (this._terminateError)
+      terminatePromise.resolve(this._terminateError);
+    this._terminatePromises.add(terminatePromise);
+    try {
+      return await Promise.race([
+        terminatePromise.then(e => safe ? defaultValue : Promise.reject(e)),
+        ...promises
+      ]);
+    } finally {
+      this._terminatePromises.delete(terminatePromise);
+    }
+  }
+}