Puppeteer Devtools Programaticaly

Question

I can open the devtools that exist in Puppeteer, but I cannot write data to the console section and export the log of this data to the cmd screen?

In Puppeteer, I want to print to console as below and get the output below.

Screenshot

Answer 1

You are asking for two things here

1. Capture console.log messages to the command prompt
2. Run a javascript command inside puppeteer

For the first point you can set the option dumpio: true as a option

For the second point you can jump into the page using evaluate and make a call to console.log

    const puppeteer = require('puppeteer');

    (async () => {
      const browser = await puppeteer.launch({
        dumpio: true
      });
      const page = await browser.newPage();

      const url = "https://stackoverflow.com";
      await page.goto(url);

      await page.waitFor('h1');

      await page.evaluate(() => {
        console.log(document.getElementsByTagName("h1")[0].innerText);
      });

      console.log("Done.")
      await browser.close();

    })();  

Also for brevity if you are getting to much output you can omit dumpio and instead catch the log as an event e.g.

  page.on('console', (msg) => console[msg._type]('PAGE LOG:', msg._text));

  await page.waitFor('h1');

  await page.evaluate(() => {
    console.log(1 + 2);
    console.log(document.getElementsByTagName("h1")[0].innerText);
  });

the second script returns

PAGE LOG: 3
PAGE LOG: We <3 people who code
Done.