Extract Cookie from a site with Puppeteer

Puppeteer is a Node library which provides a high-level API to control Chrome or Chromium over the DevTools Protocol. Puppeteer runs headless by default, but can be configured to run full (non-headless) Chrome or Chromium. Learn more about puppeteer here.In this article, we will write a script that will automatically logs you in from the google oauth form and scrape the cookie data from the site.

Below are the use cases of it:

1. Test automation in modern web applications: verifying that the features we are exposing our users/customers to are actually behaving as expected.
2. Taking screenshots of web pages: useful for a variety of different uses going from simple archiving to automated comparison for e.g. visual testing.
3. Scraping web sites for data: extracting data from websites for later retrieval or analysis.
4. Automating interaction of web pages: speed up and scale any sort of sequence of actions we would like to perform on a website automatically.

Let's scrape a site,shall we?

Create a Project Folder and structure it as below:

root
          ------------ script.js
          ----- cookies.json
          ----- config.json

In cookie,json file.Add a { } as below:

{ }

``
In config.json. Add mail and password as below:
```json
{

"mail":"your email",

"password":"your password"

}

Now lets install puppeteer:

npm i puppeteer

Start writing the script in script.js file.copy the below code:

const puppeteer = require("puppeteer");

const fs = require("fs");
const cookies = require("./cookies.json");
const config = require("./config.json");
(async () => {
  try {
    //* start puppeteer and creates a new page
    
    let browser = await puppeteer.launch({ headless: false });
    let page = await browser.newPage();

    //* check for any saved session
    
    if (Object.keys(cookies).length) {
      //* set the saved cookies in the pageawait page.setCookie(...cookies);
      //* go to sentinal
    await page.goto("https://sentinel.zerodha.com/", 
    { waitUntil: "networkidle2", });
} else {
await page.goto("https://sentinel.zerodha.com/login", 
{ waitUntil: "networkidle0", });

//* brings login page

await page.click('a[href="/api/accounts/google/login/"]', { delay: 30 });

//* adds emailawait page.waitForSelector('input[id="identifierId"]');

await page.type('input[id="identifierId"]', config.mail, {

delay: 30,
});
await page.click("#identifierNext");

 //* adds password
 
await page.waitForSelector('input[type="password"]', { visible: true });
await page.type('input[type="password"]', config.password);
await page.waitForSelector("#passwordNext", { visible: true });
await page.click("#passwordNext");

//* get the current browser page session

let currentCookies = await page._client.send("Network.getAllCookies");

//* creates a cookie file to store the session

 fs.writeFileSync("./cookies.json", JSON.stringify(currentCookies));
await browser.close();
}
} catch (e) {
console.log(e);
}
})();

To run the script:

node script.js

Check the cookie.json file. The file gets the cookie from the site. There are more stuffs that you can do.Hope this helps.

Happy coding...