Function fromAction

packages/svelte/src/attachments/index.js:96–113

(action, fn = /** @type {() => T} */ (noop))

 * @since 5.32
 */
export function fromAction(action, fn = /** @type {() => T} */ (noop)) {
	return (element) => {
		const { update, destroy } = untrack(() => action(element, fn()) ?? {});

		if (update) {
			var ran = false;
			render_effect(() => {
				const arg = fn();
				if (ran) update(arg);
			});
			ran = true;
		}

		if (destroy) {
			teardown(destroy);
		}
	};
}