Requested behavior for --full-page CLI option for chrome --headless --screenshot.

full-page.js

const puppeteer = require('puppeteer');

(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  await page.setViewport({width: 1440, height: 1200});
  await page.goto('https://example.com', {waitUntil: 'networkidle2'});
  await page.screenshot({path: 'screenshot.png', fullPage: true});
  await browser.close();
})();