puppeteer-screenshot.js

'use strict';

const puppeteer = require('puppeteer');

function timeout(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}
function once(emitter, event) {
  return new Promise(resolve => emitter.once(event, resolve));
}

(async() => {

  try {
    const browser = await puppeteer.launch({args: ['--no-sandbox', '--disable-setuid-sandbox']});
    const page = await browser.newPage();

    await page.goto('https://output.jsbin.com/folacafoho', {
      waitLoad: true
    });

    const buttonSelector = '#btn';
    await page.click(buttonSelector);

    const frame = await once(page, 'framenavigated');
    await frame.waitForSelector('body > img');

    const fileName = `${Date.now()}.png`;
    await page.screenshot({path: fileName});
    console.log(fileName);

    await page.close();
    await browser.close();
  } catch(err) {
    process.stderr.write(`There was an error taking the screenshot: ${err.message}`);
    process.stderr.write(err.stack);
    process.exit(1);
  }
})();