Implementation:Microsoft Playwright WkWorkers

Overview

WKWorkers manages Web Worker lifecycle for WebKit pages, creating worker sessions, execution contexts, and handling console messages from workers.

Description

The WKWorkers class listens for WebKit Worker.workerCreated and Worker.workerTerminated events to manage the lifecycle of web workers within a page. For each worker:

• Creates a WKSession that proxies messages through the parent session
• Establishes an execution context using WKExecutionContext
• Enables Runtime and Console protocol domains
• Forwards console messages from workers to the page
• Cleans up sessions and workers on termination or page navigation

Usage

Created internally per WebKit page. Workers are tracked and accessible through the page's worker API.

Code Reference

Source Location

packages/playwright-core/src/server/webkit/wkWorkers.ts (109 lines)

Class Signature

export class WKWorkers {
  constructor(page: Page)
  setSession(session: WKSession): void
  clear(): void
}

Import

import { WKWorkers } from './server/webkit/wkWorkers';

I/O Contract

Inputs

• page: Page -- the parent page owning the workers
• session: WKSession -- the page session for worker event listeners

Outputs

• Creates Worker instances registered on the page
• Establishes execution contexts for each worker
• Handles console message forwarding

Related Pages

• Microsoft_Playwright_WkConnection -- WebKit sessions used for worker communication
• Microsoft_Playwright_WkExecutionContext -- Execution context for workers