page.evaluate() - document is undefined when returning it back to Node

Question

I tried to get the Document of a Website with Puppetter but somehow page.evaluate doesnt work the way i thought.

  let browser = await puppeteer.launch({headless:true});
  let page = await browser.newPage();
  await page.setViewport({
    width: 1920,
    height: 1080
  })
  await page.goto('https://www.tradingview.com/chart/');

  const doc = await page.evaluate(() => {
    return document;
  });
  
  console.log(doc) 

When i print doc it prints undefined

Answer 1

Unfortunately, page.evaluate() can only transfer serializable values (roughly, the values JSON can handle). As document returns a DOM element that is not serializable (it contains methods and circular references), it is replaced with undefined. You need to return either serializable value (for example, document.body.innerText) or use something like page.evaluateHandle() and JSHandle API.