Intercept console messages/errors from a page

[Nashorn]

How can HappyDOM be used to intercept the console messages of a webpage being loaded?

[capricorn86]

Hi @Nashorn!

You can listen for console messages of a page with the VirtualConsolePrinter.

import { Browser } from "happy-dom";

const browser = new Browser();
const page = browser.newPage();
const messages = [];

page.virtualConsolePrinter.addEventListener('print', () => {
       messages.push(page.virtualConsolePrinter.readAsString());
});

// Do something with console messages
console.log(messages);

I'm working on a solution in #1730, which will make it possible to intercept the Window object before the document content has been loaded. This will make it possible to listen for the Window error event.

E.g.

const browser = new Browser({
    settings: {
         navigation: {
             beforeContentCallback: (window) => {
                 window.addEventListener('error', (event) => {
                       // Do something with error
                 });
             }
         }
    }
 });
const page = browser.newPage();
await page.goto('https://www.example.com');

or

await page.goto('https://www.example.com', {
    beforeContentCallback: (window) => {
        window.addEventListener('error', (event) => {
            // Do something with error
        });
    }
});

[capricorn86]

@Nashorn it is now possible to intercept using beforeContentCallback