medium_puppeteer_iframe_1.ts

async renderPageToHtml(page: Page): Promise<string> {
  const iframes = await page.$$("iframe");
  for (const iframe of iframes) {
    const frame = await iframe.contentFrame();
    if (!frame) continue;
    const context = await frame.executionContext();
    const res = await context.evaluate(() => {
      const el = document.querySelector("*");
      if (el) return el.outerHTML;
    });
    if (res) {
      await iframe.evaluate((a, res) => {
        a.innerHTML = res;
      }, res);
    }
  }

  return await page.evaluate(() => new XMLSerializer().serializeToString(document));
}