reuse browser instance puppeterr - node.js

Question

I would like to know if it is possible to have one .js file that opens a browser instance, creates new page/tab logs in to a website (with username/password) and just stays idle. And in a second .js file use file one browser instance and its page.
1.js
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch({
headless: true,
args: ['--no-sandbox'],
ignoreDefaultArgs: ["--hide-scrollbars"]
});
const page = await browser.newPage();
const response = await page.goto('https://google.com');
console.log('Browser open in the background (headless)!');
//await browser.close();
})();
2.js
const puppeteer = require('puppeteer');
(async () => {
// instructions on browser instance/page from 1.js ...
})();

Answer 1

The crawler object keeps the state of the browser instance and
wherever you call/pass that instance, it refers to the same chromium
in the "background". If this is an overkill, and you just want to
connect to an already running chromium using puppeteer, you can do it
with puppeteer.connect. take a look at this:
How to "hook in" puppeteer into a running Chrome instance/tab – mbit
Yeah I guess its to overkill for me :). But the link you posted was what I wanted but have 2 questions.
This Is a sample what I have.
// 1.js
// open chromium, new tab, go to google.com, print browserWSEndpoint, disconnect
const puppeteer = require('puppeteer');
(async () => {
var browser = await puppeteer.launch({headless: false});
var page = await browser.newPage();
var response = await page.goto('https://google.com');
var browserWSEndpoint = browser.wsEndpoint();
console.log(browserWSEndpoint); // prints: ws://127.0.0.1:51945/devtools/browser/6462daeb-469b-4ae4-bfd1-c3bd2f26aa5e
browser.disconnect();
})();
And
// 2.js
// connect to the open browser with the browserWSEndpoint manualy put in, ... , disconect.
const puppeteer = require('puppeteer');
(async () => {
var browser = await puppeteer.connect({browserWSEndpoint: 'ws://127.0.0.1:51945/devtools/browser/6462daeb-469b-4ae4-bfd1-c3bd2f26aa5e'});
// somehow use the tab that is open from 1.js (google.com)
await browser.disconnect();
})();
I get the browserWSEndpoint string from the console.log 1.js.
It works great but I have two difficulties.
1 - How can I use the variable browserWSEndpoint from 1.js so I dont have to always copy paste it to 2.js.
2- If I open a new page/tab on 1.js and go for example to google and disconnect (browser.disconnect()), how can use that page/tab on 2.js.

Answer 2

Working tested code
getEmail.js is where actual page will be exported. ask clarifications in comments.
getBrowser.js
const puppeteer = require("puppeteer");
module.exports = {
browser: {},
pptr_instance_url:"",
getBrow: async function(){ try {
console.log("line6",this.pptr_instance_url);
this.browser = await puppeteer.connect({browserWSEndpoint: this.pptr_instance_url}).catch(async e =>{
console.log("end point",this.pptr_instance_url);
this.browser = await puppeteer.launch({timeout: 0});
this.pptr_instance_url = this.browser.wsEndpoint();
console.log("line 11",this.pptr_instance_url);
return this.browser;
});
return this.browser;
}catch (e){
console.log(e)
} }
}
pageRenderer.js
const abc = require("../getBrowsernew")
const pageRenderer = async (request) => {
const {reactProjectUrl} = constants, uuidStorageKey = uuidv4(),
localStorageObject = {[uuidStorageKey]: request.body};
const browser = await abc.getBrow();
let url = "someurl.com"
await setLocalStorage(browser, url, localStorageObject);
const page = await browser.newPage();
const response = await page.goto(
url,
{
waitUntil: "networkidle0"
}, {waitUntil: 'load', timeout: 0}
);
return page;
}
module.exports = pageRenderer;
getEmail.js
const pageRenderer = require("./pageRenderer");
const getEmail =async (request) =>{
const page = await pageRenderer(request)
const emailbody = await page.content();
page.close();
return emailbody;
}
module.exports = getEmail;

Answer 3

You can implement this in many ways like having separate modules with functions, or different classes, and it depends on your particular need.
You can have a class that launches the browser and creates pages plus some extra functionalities.
//1.js
const puppeteer = require('puppeteer');
class Crawler {
constructor() {
//init with whatever values you'll need in your class
//or throw an error if the object wasn't created through build
}
static async build() {
let crawler = new Crawler();
await crawler._init();
return crawler;
}
async _init() {
//launch the browser and keep its state
this._browser = await puppeteer.launch({timeout: 0});
//create a page and keep its state
this._page = await this._browser.newPage();
}
//getter
get browser() {
return this._browser;
}
//getter
get page() {
return this._page;
}
async login(url) {
await this._page.goto(url);
//do whatever is related to the login process
}
}
module.exports = {Crawler};
Note that we can't have async functions in the constructor. Since launching browser is async, we use something like a build function to initiate the browser when creating the object. Then we create the crawler object like this:
//2.js
const {Crawler} = require('./1.js');
(async() => {
let crawler = await Crawler.build();
await crawler.login("https://example.com");
//access crawler's page
console.log(crawler.page.url());
})();
Keep in mind that this is only an example and by no means representative of the best practices. So first, you need to understand what you want to achieve out of such encapsulation, then adopt the method that suits you best.
Read more on JS classes here