How to take screenshots for multiple pages automatically using Puppeteer

Question

I have a list of URLs in the text file. I want to get the screenshot for each page automatically by reading each URL form the text file using Puppeteer.

const puppeteer = require('puppeteer');
async function doScreenCapture(url, site_name) {
    let browser = await puppeteer.launch({ headless: false });
    let page = await browser.newPage();
    await page.goto(url);
    await page.setViewport({width: 1382, height: 717})
    await page.waitFor(1000);
    console.log('do screen capture running');
    await page.screenshot({ path:`${site_name}.png`, fullPage: true });
    await page.close();
    await browser.close();
  }
async function run() {
    console.log('running');
    var fs = require("fs");
    var text = fs.readFileSync("linksList.txt").toString().split("\n");

    for (var i = 0; i < text.length; ++i) {
            doScreenCapture(text[i], "image"+i)
            console.log("image"+i+" completed");
            await page.waitFor(5000);
        }
 }

run();

This is the error I got while running the code

(node:77868) UnhandledPromiseRejectionWarning: ReferenceError: page is not defined at run at Object. at Module._compile (module.js:653:30) at Object.Module._extensions..js (module.js:664:10) at Module.load (module.js:566:32) at tryModuleLoad (module.js:506:12) at Function.Module._load (module.js:498:3) at Function.Module.runMain (module.js:694:10) at startup (bootstrap_node.js:204:16) at bootstrap_node.js:625:3 (node:77868) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1) (node:77868) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. do screen capture running.

Answer 1

I see two issues here:

• page does not exist in the "for" loop, only in the "run" function and that gives you the exception. You can move waiting to the function

• "doScreenCapture" is an async function and you should use await doScreenCapture in order for pages to be open in succession, not at once.