chore: conditionally dispatch network events (#18687)

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

@@ -96,6 +96,13 @@ export class BrowserContext extends ChannelOwner<channels.BrowserContextChannel>
     this._channel.on('requestFinished', params => this._onRequestFinished(params));
     this._channel.on('response', ({ response, page }) => this._onResponse(network.Response.from(response), Page.fromNullable(page)));
     this._closedPromise = new Promise(f => this.once(Events.BrowserContext.Close, f));
+
+    this._setEventToSubscriptionMapping(new Map<string, channels.BrowserContextUpdateSubscriptionParams['event']>([
+      [Events.BrowserContext.Request, 'request'],
+      [Events.BrowserContext.Response, 'response'],
+      [Events.BrowserContext.RequestFinished, 'requestFinished'],
+      [Events.BrowserContext.RequestFailed, 'requestFailed'],
+    ]));
   }
 
   _setBrowserType(browserType: BrowserType) {

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

@@ -26,6 +26,8 @@ import type { ClientInstrumentation } from './clientInstrumentation';
 import type { Connection } from './connection';
 import type { Logger } from './types';
 
+type Listener = (...args: any[]) => void;
+
 export abstract class ChannelOwner<T extends channels.Channel = channels.Channel> extends EventEmitter {
   readonly _connection: Connection;
   private _parent: ChannelOwner | undefined;
@@ -37,6 +39,7 @@ export abstract class ChannelOwner<T extends channels.Channel = channels.Channel
   readonly _initializer: channels.InitializerTraits<T>;
   _logger: Logger | undefined;
   _instrumentation: ClientInstrumentation | undefined;
+  private _eventToSubscriptionMapping: Map<string, string> = new Map();
 
   constructor(parent: ChannelOwner | Connection, type: string, guid: string, initializer: channels.InitializerTraits<T>, instrumentation?: ClientInstrumentation) {
     super();
@@ -57,6 +60,51 @@ export abstract class ChannelOwner<T extends channels.Channel = channels.Channel
     this._initializer = initializer;
   }
 
+  _setEventToSubscriptionMapping(mapping: Map<string, string>) {
+    this._eventToSubscriptionMapping = mapping;
+  }
+
+  private _updateSubscription(event: string | symbol, enabled: boolean) {
+    const protocolEvent = this._eventToSubscriptionMapping.get(String(event));
+    if (protocolEvent)
+      (this._channel as any).updateSubscription({ event: protocolEvent, enabled }).catch(() => {});
+  }
+
+  override on(event: string | symbol, listener: Listener): this {
+    if (!this.listenerCount(event))
+      this._updateSubscription(event, true);
+    super.on(event, listener);
+    return this;
+  }
+
+  override addListener(event: string | symbol, listener: Listener): this {
+    if (!this.listenerCount(event))
+      this._updateSubscription(event, true);
+    super.addListener(event, listener);
+    return this;
+  }
+
+  override prependListener(event: string | symbol, listener: Listener): this {
+    if (!this.listenerCount(event))
+      this._updateSubscription(event, true);
+    super.prependListener(event, listener);
+    return this;
+  }
+
+  override off(event: string | symbol, listener: Listener): this {
+    super.off(event, listener);
+    if (!this.listenerCount(event))
+      this._updateSubscription(event, false);
+    return this;
+  }
+
+  override removeListener(event: string | symbol, listener: Listener): this {
+    super.removeListener(event, listener);
+    if (!this.listenerCount(event))
+      this._updateSubscription(event, false);
+    return this;
+  }
+
   _adopt(child: ChannelOwner<any>) {
     child._parent!._objects.delete(child._guid);
     this._objects.set(child._guid, child);

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

@@ -66,7 +66,6 @@ type PDFOptions = Omit<channels.PagePdfParams, 'width' | 'height' | 'margin'> &
   },
   path?: string,
 };
-type Listener = (...args: any[]) => void;
 
 type ExpectScreenshotOptions = Omit<channels.PageExpectScreenshotOptions, 'screenshotOptions' | 'locator' | 'expected'> & {
   expected?: Buffer,
@@ -161,6 +160,14 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
       new Promise<void>(f => this.once(Events.Page.Close, f)),
       new Promise<void>(f => this.once(Events.Page.Crash, f)),
     ]);
+
+    this._setEventToSubscriptionMapping(new Map<string, channels.PageUpdateSubscriptionParams['event']>([
+      [Events.Page.Request, 'request'],
+      [Events.Page.Response, 'response'],
+      [Events.Page.RequestFinished, 'requestFinished'],
+      [Events.Page.RequestFailed, 'requestFailed'],
+      [Events.Page.FileChooser, 'fileChooser'],
+    ]));
   }
 
   private _onFrameAttached(frame: Frame) {
@@ -693,41 +700,6 @@ export class Page extends ChannelOwner<channels.PageChannel> implements api.Page
     return [...this._workers];
   }
 
-  override on(event: string | symbol, listener: Listener): this {
-    if (event === Events.Page.FileChooser && !this.listenerCount(event))
-      this._channel.setFileChooserInterceptedNoReply({ intercepted: true });
-    super.on(event, listener);
-    return this;
-  }
-
-  override addListener(event: string | symbol, listener: Listener): this {
-    if (event === Events.Page.FileChooser && !this.listenerCount(event))
-      this._channel.setFileChooserInterceptedNoReply({ intercepted: true });
-    super.addListener(event, listener);
-    return this;
-  }
-
-  override prependListener(event: string | symbol, listener: Listener): this {
-    if (event === Events.Page.FileChooser && !this.listenerCount(event))
-      this._channel.setFileChooserInterceptedNoReply({ intercepted: true });
-    super.prependListener(event, listener);
-    return this;
-  }
-
-  override off(event: string | symbol, listener: Listener): this {
-    super.off(event, listener);
-    if (event === Events.Page.FileChooser && !this.listenerCount(event))
-      this._channel.setFileChooserInterceptedNoReply({ intercepted: false });
-    return this;
-  }
-
-  override removeListener(event: string | symbol, listener: Listener): this {
-    super.removeListener(event, listener);
-    if (event === Events.Page.FileChooser && !this.listenerCount(event))
-      this._channel.setFileChooserInterceptedNoReply({ intercepted: false });
-    return this;
-  }
-
   async pause() {
     if (!require('inspector').url())
       await this.context()._channel.pause();

packages/playwright-core/src/protocol/validator.ts

@@ -869,6 +869,11 @@ scheme.BrowserContextCreateTempFileParams = tObject({
 scheme.BrowserContextCreateTempFileResult = tObject({
   writableStream: tChannel(['WritableStream']),
 });
+scheme.BrowserContextUpdateSubscriptionParams = tObject({
+  event: tEnum(['request', 'response', 'requestFinished', 'requestFailed']),
+  enabled: tBoolean,
+});
+scheme.BrowserContextUpdateSubscriptionResult = tOptional(tObject({}));
 scheme.PageInitializer = tObject({
   mainFrame: tChannel(['Frame']),
   viewportSize: tOptional(tObject({
@@ -927,10 +932,6 @@ scheme.PageSetDefaultTimeoutNoReplyParams = tObject({
   timeout: tOptional(tNumber),
 });
 scheme.PageSetDefaultTimeoutNoReplyResult = tOptional(tObject({}));
-scheme.PageSetFileChooserInterceptedNoReplyParams = tObject({
-  intercepted: tBoolean,
-});
-scheme.PageSetFileChooserInterceptedNoReplyResult = tOptional(tObject({}));
 scheme.PageAddInitScriptParams = tObject({
   source: tString,
 });
@@ -1162,6 +1163,11 @@ scheme.PageStopCSSCoverageResult = tObject({
 });
 scheme.PageBringToFrontParams = tOptional(tObject({}));
 scheme.PageBringToFrontResult = tOptional(tObject({}));
+scheme.PageUpdateSubscriptionParams = tObject({
+  event: tEnum(['fileChooser', 'request', 'response', 'requestFinished', 'requestFailed']),
+  enabled: tBoolean,
+});
+scheme.PageUpdateSubscriptionResult = tOptional(tObject({}));
 scheme.FrameInitializer = tObject({
   url: tString,
   name: tString,

packages/playwright-core/src/server/dispatchers/artifactDispatcher.ts

@@ -15,7 +15,7 @@
  */
 
 import type * as channels from '@protocol/channels';
-import { Dispatcher } from './dispatcher';
+import { Dispatcher, existingDispatcher } from './dispatcher';
 import type { DispatcherScope } from './dispatcher';
 import { StreamDispatcher } from './streamDispatcher';
 import fs from 'fs';
@@ -24,7 +24,19 @@ import type { Artifact } from '../artifact';
 
 export class ArtifactDispatcher extends Dispatcher<Artifact, channels.ArtifactChannel, DispatcherScope> implements channels.ArtifactChannel {
   _type_Artifact = true;
-  constructor(scope: DispatcherScope, artifact: Artifact) {
+
+  static from(parentScope: DispatcherScope, artifact: Artifact): ArtifactDispatcher {
+    return ArtifactDispatcher.fromNullable(parentScope, artifact)!;
+  }
+
+  static fromNullable(parentScope: DispatcherScope, artifact: Artifact): ArtifactDispatcher | undefined {
+    if (!artifact)
+      return undefined;
+    const result = existingDispatcher<ArtifactDispatcher>(artifact);
+    return result || new ArtifactDispatcher(parentScope, artifact);
+  }
+
+  private constructor(scope: DispatcherScope, artifact: Artifact) {
     super(scope, artifact, 'Artifact', {
       absolutePath: artifact.localPath(),
     });

packages/playwright-core/src/server/dispatchers/browserContextDispatcher.ts

@@ -15,7 +15,7 @@
  */
 
 import { BrowserContext } from '../browserContext';
-import { Dispatcher, lookupDispatcher } from './dispatcher';
+import { Dispatcher, existingDispatcher } from './dispatcher';
 import type { DispatcherScope } from './dispatcher';
 import { PageDispatcher, BindingCallDispatcher, WorkerDispatcher } from './pageDispatcher';
 import type { FrameDispatcher } from './frameDispatcher';
@@ -38,6 +38,7 @@ export class BrowserContextDispatcher extends Dispatcher<BrowserContext, channel
   _type_EventTarget = true;
   _type_BrowserContext = true;
   private _context: BrowserContext;
+  private _subscriptions = new Set<channels.BrowserContextUpdateSubscriptionParams['event']>();
 
   constructor(parentScope: DispatcherScope, context: BrowserContext) {
     // We will reparent these to the context below.
@@ -60,7 +61,7 @@ export class BrowserContextDispatcher extends Dispatcher<BrowserContext, channel
     const onVideo = (artifact: Artifact) => {
       // Note: Video must outlive Page and BrowserContext, so that client can saveAs it
       // after closing the context. We use |scope| for it.
-      const artifactDispatcher = new ArtifactDispatcher(parentScope, artifact);
+      const artifactDispatcher = ArtifactDispatcher.from(parentScope, artifact);
       this._dispatchEvent('video', { artifact: artifactDispatcher });
     };
     this.addObjectListener(BrowserContext.Events.VideoStarted, onVideo);
@@ -88,27 +89,56 @@ export class BrowserContextDispatcher extends Dispatcher<BrowserContext, channel
       this.addObjectListener(CRBrowserContext.CREvents.ServiceWorker, serviceWorker => this._dispatchEvent('serviceWorker', { worker: new WorkerDispatcher(this, serviceWorker) }));
     }
     this.addObjectListener(BrowserContext.Events.Request, (request: Request) =>  {
-      return this._dispatchEvent('request', {
-        request: RequestDispatcher.from(this, request),
+      const redirectFromDispatcher = request.redirectedFrom() && existingDispatcher(request.redirectedFrom());
+      if (!redirectFromDispatcher && !this._shouldDispatchNetworkEvent(request, 'request'))
+        return;
+      const requestDispatcher = RequestDispatcher.from(this, request);
+      this._dispatchEvent('request', {
+        request: requestDispatcher,
         page: PageDispatcher.fromNullable(this, request.frame()?._page.initializedOrUndefined())
       });
     });
-    this.addObjectListener(BrowserContext.Events.Response, (response: Response) => this._dispatchEvent('response', {
-      response: ResponseDispatcher.from(this, response),
-      page: PageDispatcher.fromNullable(this, response.frame()?._page.initializedOrUndefined())
-    }));
-    this.addObjectListener(BrowserContext.Events.RequestFailed, (request: Request) => this._dispatchEvent('requestFailed', {
-      request: RequestDispatcher.from(this, request),
-      failureText: request._failureText || undefined,
-      responseEndTiming: request._responseEndTiming,
-      page: PageDispatcher.fromNullable(this, request.frame()?._page.initializedOrUndefined())
-    }));
-    this.addObjectListener(BrowserContext.Events.RequestFinished, ({ request, response }: { request: Request, response: Response | null }) => this._dispatchEvent('requestFinished', {
-      request: RequestDispatcher.from(this, request),
-      response: ResponseDispatcher.fromNullable(this, response),
-      responseEndTiming: request._responseEndTiming,
-      page: PageDispatcher.fromNullable(this, request.frame()?._page.initializedOrUndefined()),
-    }));
+    this.addObjectListener(BrowserContext.Events.Response, (response: Response) => {
+      const requestDispatcher = existingDispatcher<RequestDispatcher>(response.request());
+      if (!requestDispatcher && !this._shouldDispatchNetworkEvent(response.request(), 'response'))
+        return;
+      this._dispatchEvent('response', {
+        response: ResponseDispatcher.from(this, response),
+        page: PageDispatcher.fromNullable(this, response.frame()?._page.initializedOrUndefined())
+      });
+    });
+    this.addObjectListener(BrowserContext.Events.RequestFailed, (request: Request) => {
+      const requestDispatcher = existingDispatcher<RequestDispatcher>(request);
+      if (!requestDispatcher && !this._shouldDispatchNetworkEvent(request, 'requestFailed'))
+        return;
+      this._dispatchEvent('requestFailed', {
+        request: RequestDispatcher.from(this, request),
+        failureText: request._failureText || undefined,
+        responseEndTiming: request._responseEndTiming,
+        page: PageDispatcher.fromNullable(this, request.frame()?._page.initializedOrUndefined())
+      });
+    });
+    this.addObjectListener(BrowserContext.Events.RequestFinished, ({ request, response }: { request: Request, response: Response | null }) => {
+      const requestDispatcher = existingDispatcher<RequestDispatcher>(request);
+      if (!requestDispatcher && !this._shouldDispatchNetworkEvent(request, 'requestFinished'))
+        return;
+      this._dispatchEvent('requestFinished', {
+        request: RequestDispatcher.from(this, request),
+        response: ResponseDispatcher.fromNullable(this, response),
+        responseEndTiming: request._responseEndTiming,
+        page: PageDispatcher.fromNullable(this, request.frame()?._page.initializedOrUndefined()),
+      });
+    });
+  }
+
+  private _shouldDispatchNetworkEvent(request: Request, event: channels.BrowserContextUpdateSubscriptionParams['event'] & channels.PageUpdateSubscriptionParams['event']): boolean {
+    if (this._subscriptions.has(event))
+      return true;
+    const page = request.frame()?._page?.initializedOrUndefined();
+    const pageDispatcher = page ? existingDispatcher<PageDispatcher>(page) : undefined;
+    if (pageDispatcher?._subscriptions.has(event))
+      return true;
+    return false;
   }
 
   async createTempFile(params: channels.BrowserContextCreateTempFileParams, metadata?: channels.Metadata): Promise<channels.BrowserContextCreateTempFileResult> {
@@ -138,7 +168,7 @@ export class BrowserContextDispatcher extends Dispatcher<BrowserContext, channel
   }
 
   async newPage(params: channels.BrowserContextNewPageParams, metadata: CallMetadata): Promise<channels.BrowserContextNewPageResult> {
-    return { page: lookupDispatcher<PageDispatcher>(await this._context.newPage(metadata)) };
+    return { page: PageDispatcher.from(this, await this._context.newPage(metadata)) };
   }
 
   async cookies(params: channels.BrowserContextCookiesParams): Promise<channels.BrowserContextCookiesResult> {
@@ -225,7 +255,14 @@ export class BrowserContextDispatcher extends Dispatcher<BrowserContext, channel
     const artifact = await this._context._harExport(params.harId);
     if (!artifact)
       throw new Error('No HAR artifact. Ensure record.harPath is set.');
-    return { artifact: new ArtifactDispatcher(this, artifact) };
+    return { artifact: ArtifactDispatcher.from(this, artifact) };
+  }
+
+  async updateSubscription(params: channels.BrowserContextUpdateSubscriptionParams, metadata?: channels.Metadata | undefined): Promise<void> {
+    if (params.enabled)
+      this._subscriptions.add(params.event);
+    else
+      this._subscriptions.delete(params.event);
   }
 
   override _dispose() {

packages/playwright-core/src/server/dispatchers/dispatcher.ts

@@ -18,7 +18,7 @@ import { EventEmitter } from 'events';
 import type * as channels from '@protocol/channels';
 import { serializeError } from '../../protocol/serializers';
 import { findValidator, ValidationError, createMetadataValidator, type ValidatorContext } from '../../protocol/validator';
-import { assert, debugAssert, isUnderTest, monotonicTime } from '../../utils';
+import { assert, isUnderTest, monotonicTime } from '../../utils';
 import { kBrowserOrContextClosedError } from '../../common/errors';
 import type { CallMetadata } from '../instrumentation';
 import { SdkObject } from '../instrumentation';
@@ -30,20 +30,10 @@ import type { RegisteredListener } from '../..//utils/eventsHelper';
 export const dispatcherSymbol = Symbol('dispatcher');
 const metadataValidator = createMetadataValidator();
 
-export function lookupDispatcher<DispatcherType>(object: any): DispatcherType {
-  const result = object[dispatcherSymbol];
-  debugAssert(result);
-  return result;
-}
-
-export function existingDispatcher<DispatcherType>(object: any): DispatcherType {
+export function existingDispatcher<DispatcherType>(object: any): DispatcherType | undefined {
   return object[dispatcherSymbol];
 }
 
-export function lookupNullableDispatcher<DispatcherType>(object: any | null): DispatcherType | undefined {
-  return object ? lookupDispatcher(object) : undefined;
-}
-
 export class Dispatcher<Type extends { guid: string }, ChannelType, ParentScopeType extends DispatcherScope> extends EventEmitter implements channels.Channel {
   private _connection: DispatcherConnection;
   // Parent is always "isScope".

packages/playwright-core/src/server/dispatchers/elementHandlerDispatcher.ts

@@ -18,14 +18,15 @@ import type { ElementHandle } from '../dom';
 import type { Frame } from '../frames';
 import type * as js from '../javascript';
 import type * as channels from '@protocol/channels';
-import { existingDispatcher, lookupNullableDispatcher } from './dispatcher';
+import { existingDispatcher } from './dispatcher';
 import { JSHandleDispatcher, serializeResult, parseArgument } from './jsHandleDispatcher';
 import type { JSHandleDispatcherParentScope } from './jsHandleDispatcher';
-import type { FrameDispatcher } from './frameDispatcher';
+import { FrameDispatcher } from './frameDispatcher';
 import type { CallMetadata } from '../instrumentation';
 import type { WritableStreamDispatcher } from './writableStreamDispatcher';
 import { assert } from '../../utils';
 import path from 'path';
+import type { PageDispatcher } from './pageDispatcher';
 
 export class ElementHandleDispatcher extends JSHandleDispatcher implements channels.ElementHandleChannel {
   _type_ElementHandle = true;
@@ -55,11 +56,13 @@ export class ElementHandleDispatcher extends JSHandleDispatcher implements chann
   }
 
   async ownerFrame(params: channels.ElementHandleOwnerFrameParams, metadata: CallMetadata): Promise<channels.ElementHandleOwnerFrameResult> {
-    return { frame: lookupNullableDispatcher<FrameDispatcher>(await this._elementHandle.ownerFrame()) };
+    const frame = await this._elementHandle.ownerFrame();
+    return { frame: frame ? FrameDispatcher.from(this.parentScope() as PageDispatcher, frame) : undefined };
   }
 
   async contentFrame(params: channels.ElementHandleContentFrameParams, metadata: CallMetadata): Promise<channels.ElementHandleContentFrameResult> {
-    return { frame: lookupNullableDispatcher<FrameDispatcher>(await this._elementHandle.contentFrame()) };
+    const frame = await this._elementHandle.contentFrame();
+    return { frame: frame ? FrameDispatcher.from(this.parentScope() as PageDispatcher, frame) : undefined };
   }
 
   async getAttribute(params: channels.ElementHandleGetAttributeParams, metadata: CallMetadata): Promise<channels.ElementHandleGetAttributeResult> {

packages/playwright-core/src/server/dispatchers/frameDispatcher.ts

@@ -17,10 +17,10 @@
 import type { NavigationEvent } from '../frames';
 import { Frame } from '../frames';
 import type * as channels from '@protocol/channels';
-import { Dispatcher, lookupNullableDispatcher, existingDispatcher } from './dispatcher';
+import { Dispatcher, existingDispatcher } from './dispatcher';
 import { ElementHandleDispatcher } from './elementHandlerDispatcher';
 import { parseArgument, serializeResult } from './jsHandleDispatcher';
-import type { ResponseDispatcher } from './networkDispatchers';
+import { ResponseDispatcher } from './networkDispatchers';
 import { RequestDispatcher } from './networkDispatchers';
 import type { CallMetadata } from '../instrumentation';
 import type { WritableStreamDispatcher } from './writableStreamDispatcher';
@@ -62,13 +62,13 @@ export class FrameDispatcher extends Dispatcher<Frame, channels.FrameChannel, Pa
         return;
       const params = { url: event.url, name: event.name, error: event.error ? event.error.message : undefined };
       if (event.newDocument)
-        (params as any).newDocument = { request: RequestDispatcher.fromNullable(scope.parentScope(), event.newDocument.request || null) };
+        (params as any).newDocument = { request: RequestDispatcher.fromNullable(this.parentScope().parentScope(), event.newDocument.request || null) };
       this._dispatchEvent('navigated', params);
     });
   }
 
   async goto(params: channels.FrameGotoParams, metadata: CallMetadata): Promise<channels.FrameGotoResult> {
-    return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._frame.goto(metadata, params.url, params)) };
+    return { response: ResponseDispatcher.fromNullable(this.parentScope().parentScope(), await this._frame.goto(metadata, params.url, params)) };
   }
 
   async frameElement(): Promise<channels.FrameFrameElementResult> {

packages/playwright-core/src/server/dispatchers/networkDispatchers.ts

@@ -20,7 +20,7 @@ import type { CallMetadata } from '../instrumentation';
 import type { Request, Response, Route } from '../network';
 import { WebSocket } from '../network';
 import type { RootDispatcher } from './dispatcher';
-import { Dispatcher, existingDispatcher, lookupNullableDispatcher } from './dispatcher';
+import { Dispatcher, existingDispatcher } from './dispatcher';
 import { TracingDispatcher } from './tracingDispatcher';
 import type { BrowserContextDispatcher } from './browserContextDispatcher';
 import type { PageDispatcher } from './pageDispatcher';
@@ -60,7 +60,7 @@ export class RequestDispatcher extends Dispatcher<Request, channels.RequestChann
   }
 
   async response(): Promise<channels.RequestResponseResult> {
-    return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._object.response()) };
+    return { response: ResponseDispatcher.fromNullable(this.parentScope(), await this._object.response()) };
   }
 }
 

packages/playwright-core/src/server/dispatchers/pageDispatcher.ts

@@ -18,13 +18,13 @@ import type { BrowserContext } from '../browserContext';
 import type { Frame } from '../frames';
 import { Page, Worker } from '../page';
 import type * as channels from '@protocol/channels';
-import { Dispatcher, existingDispatcher, lookupDispatcher, lookupNullableDispatcher } from './dispatcher';
+import { Dispatcher, existingDispatcher } from './dispatcher';
 import { parseError, serializeError } from '../../protocol/serializers';
 import { ConsoleMessageDispatcher } from './consoleMessageDispatcher';
 import { DialogDispatcher } from './dialogDispatcher';
 import { FrameDispatcher } from './frameDispatcher';
 import { RequestDispatcher } from './networkDispatchers';
-import type { ResponseDispatcher } from './networkDispatchers';
+import { ResponseDispatcher } from './networkDispatchers';
 import { RouteDispatcher, WebSocketDispatcher } from './networkDispatchers';
 import { serializeResult, parseArgument } from './jsHandleDispatcher';
 import { ElementHandleDispatcher } from './elementHandlerDispatcher';
@@ -42,6 +42,7 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
   _type_EventTarget = true;
   _type_Page = true;
   private _page: Page;
+  _subscriptions = new Set<channels.PageUpdateSubscriptionParams['event']>();
 
   static from(parentScope: BrowserContextDispatcher, page: Page): PageDispatcher {
     return PageDispatcher.fromNullable(parentScope, page)!;
@@ -80,7 +81,7 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
     this.addObjectListener(Page.Events.Dialog, dialog => this._dispatchEvent('dialog', { dialog: new DialogDispatcher(this, dialog) }));
     this.addObjectListener(Page.Events.Download, (download: Download) => {
       // Artifact can outlive the page, so bind to the context scope.
-      this._dispatchEvent('download', { url: download.url, suggestedFilename: download.suggestedFilename(), artifact: new ArtifactDispatcher(parentScope, download.artifact) });
+      this._dispatchEvent('download', { url: download.url, suggestedFilename: download.suggestedFilename(), artifact: ArtifactDispatcher.from(parentScope, download.artifact) });
     });
     this.addObjectListener(Page.Events.FileChooser, (fileChooser: FileChooser) => this._dispatchEvent('fileChooser', {
       element: ElementHandleDispatcher.from(this, fileChooser.element()),
@@ -91,9 +92,9 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
     this.addObjectListener(Page.Events.PageError, error => this._dispatchEvent('pageError', { error: serializeError(error) }));
     this.addObjectListener(Page.Events.WebSocket, webSocket => this._dispatchEvent('webSocket', { webSocket: new WebSocketDispatcher(this, webSocket) }));
     this.addObjectListener(Page.Events.Worker, worker => this._dispatchEvent('worker', { worker: new WorkerDispatcher(this, worker) }));
-    this.addObjectListener(Page.Events.Video, (artifact: Artifact) => this._dispatchEvent('video', { artifact: existingDispatcher<ArtifactDispatcher>(artifact) }));
+    this.addObjectListener(Page.Events.Video, (artifact: Artifact) => this._dispatchEvent('video', { artifact: ArtifactDispatcher.from(parentScope, artifact) }));
     if (page._video)
-      this._dispatchEvent('video', { artifact: existingDispatcher<ArtifactDispatcher>(page._video) });
+      this._dispatchEvent('video', { artifact: ArtifactDispatcher.from(this.parentScope(), page._video) });
     // Ensure client knows about all frames.
     const frames = page._frameManager.frames();
     for (let i = 1; i < frames.length; i++)
@@ -125,15 +126,15 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
   }
 
   async reload(params: channels.PageReloadParams, metadata: CallMetadata): Promise<channels.PageReloadResult> {
-    return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._page.reload(metadata, params)) };
+    return { response: ResponseDispatcher.fromNullable(this.parentScope(), await this._page.reload(metadata, params)) };
   }
 
   async goBack(params: channels.PageGoBackParams, metadata: CallMetadata): Promise<channels.PageGoBackResult> {
-    return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._page.goBack(metadata, params)) };
+    return { response: ResponseDispatcher.fromNullable(this.parentScope(), await this._page.goBack(metadata, params)) };
   }
 
   async goForward(params: channels.PageGoForwardParams, metadata: CallMetadata): Promise<channels.PageGoForwardResult> {
-    return { response: lookupNullableDispatcher<ResponseDispatcher>(await this._page.goForward(metadata, params)) };
+    return { response: ResponseDispatcher.fromNullable(this.parentScope(), await this._page.goForward(metadata, params)) };
   }
 
   async emulateMedia(params: channels.PageEmulateMediaParams, metadata: CallMetadata): Promise<void> {
@@ -194,8 +195,13 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
     await this._page.close(metadata, params);
   }
 
-  async setFileChooserInterceptedNoReply(params: channels.PageSetFileChooserInterceptedNoReplyParams, metadata: CallMetadata): Promise<void> {
-    await this._page.setFileChooserIntercepted(params.intercepted);
+  async updateSubscription(params: channels.PageUpdateSubscriptionParams, metadata?: channels.Metadata | undefined): Promise<void> {
+    if (params.event === 'fileChooser')
+      await this._page.setFileChooserIntercepted(params.enabled);
+    if (params.enabled)
+      this._subscriptions.add(params.event);
+    else
+      this._subscriptions.delete(params.event);
   }
 
   async keyboardDown(params: channels.PageKeyboardDownParams, metadata: CallMetadata): Promise<void> {
@@ -286,7 +292,7 @@ export class PageDispatcher extends Dispatcher<Page, channels.PageChannel, Brows
   }
 
   _onFrameDetached(frame: Frame) {
-    this._dispatchEvent('frameDetached', { frame: lookupDispatcher<FrameDispatcher>(frame) });
+    this._dispatchEvent('frameDetached', { frame: FrameDispatcher.from(this, frame) });
   }
 
   override _dispose() {
@@ -330,7 +336,7 @@ export class BindingCallDispatcher extends Dispatcher<{ guid: string }, channels
 
   constructor(scope: PageDispatcher, name: string, needsHandle: boolean, source: { context: BrowserContext, page: Page, frame: Frame }, args: any[]) {
     super(scope, { guid: 'bindingCall@' + createGuid() }, 'BindingCall', {
-      frame: lookupDispatcher<FrameDispatcher>(source.frame),
+      frame: FrameDispatcher.from(scope, source.frame),
       name,
       args: needsHandle ? undefined : args.map(serializeResult),
       handle: needsHandle ? ElementHandleDispatcher.fromJSHandle(scope, args[0] as JSHandle) : undefined,

packages/playwright-core/src/server/dispatchers/tracingDispatcher.ts

@@ -43,7 +43,7 @@ export class TracingDispatcher extends Dispatcher<Tracing, channels.TracingChann
 
   async tracingStopChunk(params: channels.TracingTracingStopChunkParams): Promise<channels.TracingTracingStopChunkResult> {
     const { artifact, sourceEntries } = await this._object.stopChunk(params);
-    return { artifact: artifact ? new ArtifactDispatcher(this, artifact) : undefined, sourceEntries };
+    return { artifact: artifact ? ArtifactDispatcher.from(this, artifact) : undefined, sourceEntries };
   }
 
   async tracingStop(params: channels.TracingTracingStopParams): Promise<channels.TracingTracingStopResult> {

packages/protocol/src/channels.ts

@@ -1369,6 +1369,7 @@ export interface BrowserContextChannel extends BrowserContextEventTarget, EventT
   harStart(params: BrowserContextHarStartParams, metadata?: Metadata): Promise<BrowserContextHarStartResult>;
   harExport(params: BrowserContextHarExportParams, metadata?: Metadata): Promise<BrowserContextHarExportResult>;
   createTempFile(params: BrowserContextCreateTempFileParams, metadata?: Metadata): Promise<BrowserContextCreateTempFileResult>;
+  updateSubscription(params: BrowserContextUpdateSubscriptionParams, metadata?: Metadata): Promise<BrowserContextUpdateSubscriptionResult>;
 }
 export type BrowserContextBindingCallEvent = {
   binding: BindingCallChannel,
@@ -1598,6 +1599,14 @@ export type BrowserContextCreateTempFileOptions = {
 export type BrowserContextCreateTempFileResult = {
   writableStream: WritableStreamChannel,
 };
+export type BrowserContextUpdateSubscriptionParams = {
+  event: 'request' | 'response' | 'requestFinished' | 'requestFailed',
+  enabled: boolean,
+};
+export type BrowserContextUpdateSubscriptionOptions = {
+
+};
+export type BrowserContextUpdateSubscriptionResult = void;
 
 export interface BrowserContextEvents {
   'bindingCall': BrowserContextBindingCallEvent;
@@ -1643,7 +1652,6 @@ export interface PageChannel extends PageEventTarget, EventTargetChannel {
   _type_Page: boolean;
   setDefaultNavigationTimeoutNoReply(params: PageSetDefaultNavigationTimeoutNoReplyParams, metadata?: Metadata): Promise<PageSetDefaultNavigationTimeoutNoReplyResult>;
   setDefaultTimeoutNoReply(params: PageSetDefaultTimeoutNoReplyParams, metadata?: Metadata): Promise<PageSetDefaultTimeoutNoReplyResult>;
-  setFileChooserInterceptedNoReply(params: PageSetFileChooserInterceptedNoReplyParams, metadata?: Metadata): Promise<PageSetFileChooserInterceptedNoReplyResult>;
   addInitScript(params: PageAddInitScriptParams, metadata?: Metadata): Promise<PageAddInitScriptResult>;
   close(params: PageCloseParams, metadata?: Metadata): Promise<PageCloseResult>;
   emulateMedia(params: PageEmulateMediaParams, metadata?: Metadata): Promise<PageEmulateMediaResult>;
@@ -1674,6 +1682,7 @@ export interface PageChannel extends PageEventTarget, EventTargetChannel {
   startCSSCoverage(params: PageStartCSSCoverageParams, metadata?: Metadata): Promise<PageStartCSSCoverageResult>;
   stopCSSCoverage(params?: PageStopCSSCoverageParams, metadata?: Metadata): Promise<PageStopCSSCoverageResult>;
   bringToFront(params?: PageBringToFrontParams, metadata?: Metadata): Promise<PageBringToFrontResult>;
+  updateSubscription(params: PageUpdateSubscriptionParams, metadata?: Metadata): Promise<PageUpdateSubscriptionResult>;
 }
 export type PageBindingCallEvent = {
   binding: BindingCallChannel,
@@ -1730,13 +1739,6 @@ export type PageSetDefaultTimeoutNoReplyOptions = {
   timeout?: number,
 };
 export type PageSetDefaultTimeoutNoReplyResult = void;
-export type PageSetFileChooserInterceptedNoReplyParams = {
-  intercepted: boolean,
-};
-export type PageSetFileChooserInterceptedNoReplyOptions = {
-
-};
-export type PageSetFileChooserInterceptedNoReplyResult = void;
 export type PageAddInitScriptParams = {
   source: string,
 };
@@ -2114,6 +2116,14 @@ export type PageStopCSSCoverageResult = {
 export type PageBringToFrontParams = {};
 export type PageBringToFrontOptions = {};
 export type PageBringToFrontResult = void;
+export type PageUpdateSubscriptionParams = {
+  event: 'fileChooser' | 'request' | 'response' | 'requestFinished' | 'requestFailed',
+  enabled: boolean,
+};
+export type PageUpdateSubscriptionOptions = {
+
+};
+export type PageUpdateSubscriptionResult = void;
 
 export interface PageEvents {
   'bindingCall': PageBindingCallEvent;

packages/protocol/src/protocol.yml

@@ -1090,6 +1090,17 @@ BrowserContext:
       returns:
         writableStream: WritableStream
 
+    updateSubscription:
+      parameters:
+        event:
+          type: enum
+          literals:
+          - request
+          - response
+          - requestFinished
+          - requestFailed
+        enabled: boolean
+
   events:
 
     bindingCall:
@@ -1167,10 +1178,6 @@ Page:
       parameters:
         timeout: number?
 
-    setFileChooserInterceptedNoReply:
-      parameters:
-        intercepted: boolean
-
     addInitScript:
       parameters:
         source: string
@@ -1486,6 +1493,18 @@ Page:
 
     bringToFront:
 
+    updateSubscription:
+      parameters:
+        event:
+          type: enum
+          literals:
+          - fileChooser
+          - request
+          - response
+          - requestFinished
+          - requestFailed
+        enabled: boolean
+
   events:
 
     bindingCall:

tests/library/channels.spec.ts

@@ -183,6 +183,45 @@ it('should scope browser handles', async ({ browserType, expectScopeState }) =>
   expectScopeState(browserType, GOLDEN_PRECONDITION);
 });
 
+it('should not generate dispatchers for subresources w/o listeners', async ({ page, server, browserType, expectScopeState }) => {
+  server.setRedirect('/one-style.css', '/two-style.css');
+  server.setRedirect('/two-style.css', '/three-style.css');
+  server.setRedirect('/three-style.css', '/four-style.css');
+  server.setRoute('/four-style.css', (req, res) => res.end('body {box-sizing: border-box; }'));
+
+  await page.goto(server.PREFIX + '/one-style.html');
+
+  expectScopeState(browserType, {
+    _guid: '',
+    objects: [
+      { _guid: 'android', objects: [] },
+      { _guid: 'browser-type', objects: [] },
+      { _guid: 'browser-type', objects: [] },
+      { _guid: 'browser-type', objects: [
+        {
+          _guid: 'browser', objects: [
+            { _guid: 'browser-context', objects: [
+              {
+                _guid: 'page', objects: [
+                  { _guid: 'frame', objects: [] }
+                ]
+              },
+              { _guid: 'request', objects: [] },
+              { _guid: 'request-context', objects: [] },
+              { _guid: 'response', objects: [] },
+              { _guid: 'tracing', objects: [] }
+            ] },
+          ]
+        }],
+      },
+      { _guid: 'electron', objects: [] },
+      { _guid: 'localUtils', objects: [] },
+      { _guid: 'Playwright', objects: [] },
+      { _guid: 'selectors', objects: [] },
+    ]
+  });
+});
+
 it('should work with the domain module', async ({ browserType, server, browserName }) => {
   const local = domain.create();
   local.run(() => { });