chore: use generic implementation for BrowserContext.waitForTarget (#11848)

Co-authored-by: Alex Rudenko <OrKoN@users.noreply.github.com>

docs/api/puppeteer.browsercontext.waitfortarget.md

@@ -12,7 +12,7 @@ This will look all open [browser contexts](./puppeteer.browsercontext.md).
 
 ```typescript
 class BrowserContext {
-  abstract waitForTarget(
+  waitForTarget(
     predicate: (x: Target) => boolean | Promise<boolean>,
     options?: WaitForTargetOptions
   ): Promise<Target>;

packages/puppeteer-core/src/api/BrowserContext.ts

@@ -4,8 +4,15 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import {
+  filterAsync,
+  firstValueFrom,
+  from,
+  merge,
+  raceWith,
+} from '../../third_party/rxjs/rxjs.js';
 import {EventEmitter, type EventType} from '../common/EventEmitter.js';
-import {debugError} from '../common/util.js';
+import {debugError, fromEmitterEvent, timeout} from '../common/util.js';
 import {asyncDisposeSymbol, disposeSymbol} from '../util/disposable.js';
 
 import type {Browser, Permission, WaitForTargetOptions} from './Browser.js';
@@ -108,10 +115,19 @@ export abstract class BrowserContext extends EventEmitter<BrowserContextEvents>
    * );
    * ```
    */
-  abstract waitForTarget(
+  async waitForTarget(
     predicate: (x: Target) => boolean | Promise<boolean>,
-    options?: WaitForTargetOptions
+    options: WaitForTargetOptions = {}
-  ): Promise<Target>;
+  ): Promise<Target> {
+    const {timeout: ms = 30000} = options;
+    return await firstValueFrom(
+      merge(
+        fromEmitterEvent(this, BrowserContextEvent.TargetCreated),
+        fromEmitterEvent(this, BrowserContextEvent.TargetChanged),
+        from(this.targets())
+      ).pipe(filterAsync(predicate), raceWith(timeout(ms)))
+    );
+  }
 
   /**
    * Gets a list of all open {@link Page | pages} inside this

packages/puppeteer-core/src/bidi/BrowserContext.ts

@@ -6,7 +6,6 @@
 
 import * as Bidi from 'chromium-bidi/lib/cjs/protocol/protocol.js';
 
-import type {WaitForTargetOptions} from '../api/Browser.js';
 import {BrowserContext} from '../api/BrowserContext.js';
 import type {Page} from '../api/Page.js';
 import type {Target} from '../api/Target.js';
@@ -53,15 +52,6 @@ export class BidiBrowserContext extends BrowserContext {
     });
   }
 
-  override waitForTarget(
-    predicate: (x: Target) => boolean | Promise<boolean>,
-    options: WaitForTargetOptions = {}
-  ): Promise<Target> {
-    return this.#browser.waitForTarget(target => {
-      return target.browserContext() === this && predicate(target);
-    }, options);
-  }
-
   get connection(): BidiConnection {
     return this.#connection;
   }

packages/puppeteer-core/src/cdp/Browser.ts

@@ -18,7 +18,6 @@ import {
   type IsPageTargetCallback,
   type Permission,
   type TargetFilterCallback,
-  type WaitForTargetOptions,
 } from '../api/Browser.js';
 import {BrowserContext, BrowserContextEvent} from '../api/BrowserContext.js';
 import {CDPSessionEvent, type CDPSession} from '../api/CDPSession.js';
@@ -451,15 +450,6 @@ export class CdpBrowserContext extends BrowserContext {
     });
   }
 
-  override waitForTarget(
-    predicate: (x: Target) => boolean | Promise<boolean>,
-    options: WaitForTargetOptions = {}
-  ): Promise<Target> {
-    return this.#browser.waitForTarget(target => {
-      return target.browserContext() === this && predicate(target);
-    }, options);
-  }
-
   override async pages(): Promise<Page[]> {
     const pages = await Promise.all(
       this.targets()