read write and download file using puppeteer

readwrite.js

const puppeteer = require('puppeteer')
const fs = require('fs')
const path = require('path')
const { promisify } =require ('util')

const readFileAsync = promisify(fs.readFile)
const writeFileAsync = promisify(fs.writeFile);
(async () => {
  const browser = await puppeteer.launch({})
  const page = await browser.newPage()
  await page.setViewport({ width: 1200, height: 800 })
  await page.goto('http://www.softwaretestingtipsandtricks.com/')
  const imageHref = await page.evaluate((sel) => {
    return document.querySelector(sel).getAttribute('src').replace('/', '')
  }, '.my-thumb')
  const viewSource = await page.goto(imageHref);
  const buffer = await viewSource.buffer();
  await writeFileAsync('accessibility.png', buffer);
  console.log ('Image is saved');
  const content = await readFileAsync('accessibility.png');
  console.log('the file was read');

  await page.goto('http://www.softwaretestingtipsandtricks.com/2020/05/What-is-ada-accessibility-testing-how-to-do-it.html');
  await page.waitForSelector('.post-body');
  let element = await page.$('.post-body');
  let value = await page.evaluate(el => el.textContent, element)
  fs.writeFileSync('file.txt', value);
  const blogPost = await fs.readFileSync('file.txt');
  console.log('file was read'+blogPost);
  browser.close()
})()