How to fix waitForFunction TimeoutError of puppeteer All In One

page.waitForFunction 超时错误

error ❌

TimeoutError: Waiting failed: 30000ms exceeded

const selector = '.foo';
await page.waitForFunction((selector) => !!document.querySelector(selector));

solution ✅

const selector = '.foo';
await page.waitForFunction(
  selector => !!document.querySelector(selector),
  {},
  selector
);

demos


"use strict";

/**
 * 
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @created 2023-09-01
 * @modified 
 * 
 * @description 
 * @description 
 * @difficulty Medium
 * @time_complexity O(n)
 * @space_complexity O(n)
 * @augments 
 * @example 
 * @link https://www.cnblogs.com/xgqfrms/p/17678513.html
 * @link https://www.cnblogs.com/xgqfrms/p/17673122.html
 * @solutions 
 * 
 * @best_solutions 
 * 
 */

const log = console.log;

// import puppeteer from 'puppeteer';
const puppeteer = require('puppeteer');

class Crawler {
  constructor(url = '') {
    this.url = url;
  }
  async test (selector = '') {
    const browser = await puppeteer.launch({headless: "new"});
    const page = await browser.newPage();
    await page.goto(this.url);
    await page.setViewport({width: 1920, height: 1080});
    const matches = await page.waitForFunction((selector) => {
      console.log(`❓ selector`, selector)
      // ❌  passed selector
      const arr = [...document.querySelectorAll(selector)];
      // ✅  hard code string selector
      // const arr = [...document.querySelectorAll('.trim-title-container')];
      return arr.length ? arr : null;
    });
    console.log(`✅ matches`, matches)
    const contents = await matches.evaluate(els => els.map(e => e.innerText));
    console.log(`✅ contents`, contents)
    await browser.close();
  }
}

(async () => {
  const url = `https://www.tesla.cn/modely/design#overview`;
  const selector = `.trim-title-container`;
  const crawler = new Crawler(url)
  await crawler.test(selector);
})();

(? 反爬虫测试！打击盗版⚠️）如果你看到这个信息, 说明这是一篇剽窃的文章，请访问 https://www.cnblogs.com/xgqfrms/ 查看原创文章！

`waitForFunction`

class Page {
  waitForFunction<
    Params extends unknown[],
    Func extends EvaluateFunc<Params> = EvaluateFunc<Params>,
  >(
    pageFunction: Func | string,
    options?: FrameWaitForFunctionOptions,
    ...args: Params
  ): Promise<HandleFor<Awaited<ReturnType<Func>>>>;
}

https://pptr.dev/api/puppeteer.page.waitforfunction

`waitForSelector`

class Page {
  waitForSelector<Selector extends string>(
    selector: Selector,
    options?: WaitForSelectorOptions
  ): Promise<ElementHandle<NodeFor<Selector>> | null>;
}

https://pptr.dev/api/puppeteer.page.waitforselector