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puppeteer-core

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A high-level API to control headless Chrome over the DevTools Protocol

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/** * @license * Copyright 2022 Google Inc. * SPDX-License-Identifier: Apache-2.0 */ import { assert } from '../util/assert.js'; import { Deferred } from '../util/Deferred.js'; /** * @internal */ export class MutationPoller { #fn; #root; #observer; #deferred; constructor(fn, root) { this.#fn = fn; this.#root = root; } async start() { const deferred = (this.#deferred = Deferred.create()); const result = await this.#fn(); if (result) { deferred.resolve(result); return; } this.#observer = new MutationObserver(async () => { const result = await this.#fn(); if (!result) { return; } deferred.resolve(result); await this.stop(); }); this.#observer.observe(this.#root, { childList: true, subtree: true, attributes: true, }); } async stop() { assert(this.#deferred, 'Polling never started.'); if (!this.#deferred.finished()) { this.#deferred.reject(new Error('Polling stopped')); } if (this.#observer) { this.#observer.disconnect(); this.#observer = undefined; } } result() { assert(this.#deferred, 'Polling never started.'); return this.#deferred.valueOrThrow(); } } /** * @internal */ export class RAFPoller { #fn; #deferred; constructor(fn) { this.#fn = fn; } async start() { const deferred = (this.#deferred = Deferred.create()); const result = await this.#fn(); if (result) { deferred.resolve(result); return; } const poll = async () => { if (deferred.finished()) { return; } const result = await this.#fn(); if (!result) { window.requestAnimationFrame(poll); return; } deferred.resolve(result); await this.stop(); }; window.requestAnimationFrame(poll); } async stop() { assert(this.#deferred, 'Polling never started.'); if (!this.#deferred.finished()) { this.#deferred.reject(new Error('Polling stopped')); } } result() { assert(this.#deferred, 'Polling never started.'); return this.#deferred.valueOrThrow(); } } /** * @internal */ export class IntervalPoller { #fn; #ms; #interval; #deferred; constructor(fn, ms) { this.#fn = fn; this.#ms = ms; } async start() { const deferred = (this.#deferred = Deferred.create()); const result = await this.#fn(); if (result) { deferred.resolve(result); return; } this.#interval = setInterval(async () => { const result = await this.#fn(); if (!result) { return; } deferred.resolve(result); await this.stop(); }, this.#ms); } async stop() { assert(this.#deferred, 'Polling never started.'); if (!this.#deferred.finished()) { this.#deferred.reject(new Error('Polling stopped')); } if (this.#interval) { clearInterval(this.#interval); this.#interval = undefined; } } result() { assert(this.#deferred, 'Polling never started.'); return this.#deferred.valueOrThrow(); } } //# sourceMappingURL=Poller.js.map