Feature request: allow extending `defaultEventNames` mapping

[grncdr]

The logic for shorthand/default event names in stimulus is currently defined here:

stimulus/src/core/action.ts

Lines 89 to 97 in f7bfc35

	const defaultEventNames: { [tagName: string]: (element: Element) => string } = {
	a: () => "click",
	button: () => "click",
	form: () => "submit",
	details: () => "toggle",
	input: (e) => (e.getAttribute("type") == "submit" ? "click" : "input"),
	select: () => "change",
	textarea: () => "input",
	}

This is pretty handy, but if you are using a library of custom elements (e.g. shoelace) you have to turn <button data-action="controller#method"></button> into <sl-button data-action="click->controller#method"></sl-button>.

It's a tiny thing, but if stimulus were to simply export that mapping it would be possible for users to do something like:

import { defaultEventNames } from '@hotwired/stimulus'

defaultEventNames['sl-button'] = () => 'click'

<sl-button data-action="controller#method"></sl-button>

If exporting the mapping directly is exposing too many implementation details, a function like setDefaultEventName(elementName, stringOrCallback) would also be pretty nice.

If that makes sense to the maintainers I can take a crack at a PR.

[marcoroth]

Thanks for opening this issue @grncdr!

I wouldn't be opposed to add support for something like this. I think it would make sense to provide some sort of public interface instead of just exporting the object.