Events created with `new Event()` don't bubble to parent elements

[dy]

Events created using the Event constructor with { bubbles: true } do not bubble to parent elements, even though event.bubbles is correctly set to true.

Reproduction

const { Window } = require('happy-dom');
const window = new Window();
const document = window.document;

const parent = document.createElement('div');
const child = document.createElement('span');
parent.appendChild(child);
document.body.appendChild(parent);

let bubbled = false;
parent.addEventListener('click', () => {
  bubbled = true;
});

const event = new Event('click', { bubbles: true });
console.log('event.bubbles:', event.bubbles); // true ✓

child.dispatchEvent(event);
console.log('bubbled to parent:', bubbled); // false ✗ (should be true)

Expected behavior

The event should bubble from child to parent, triggering the parent's event listener.

Actual behavior

• event.bubbles is correctly true
• Event fires on child
• Event does NOT bubble to parent
• Parent's listener is never called

Workaround

Using the legacy createEvent/initEvent API works correctly:

const event = document.createEvent('Event');
event.initEvent('click', true, true); // (type, bubbles, cancelable)
child.dispatchEvent(event);
console.log('bubbled to parent:', bubbled); // true ✓

Impact

This breaks any code using the modern Event constructor API for custom events or synthetic event dispatching. Many testing libraries and frameworks rely on this for simulating user interactions.

Environment

• happy-dom version: 16.7.2
• Node.js version: v22.x

[capricorn86]

@dy this happens because you are using a Node Event object and not an Event object from the Happy DOM environment.

I've added a check for this to throw an error if type is not Event the same way as the browser does in the latest version of Happy DOM.

Alternative 1: Use Event from window

const { Window, Event } = require('happy-dom');
const window = new Window();
const event = new window.Event('click', { bubbles: true });

Alternative 2: Import Event

const { Window, Event } = require('happy-dom');