woocommerce/plugins/woocommerce-blocks/assets/js/interactivity/utils.js

// @ts-nocheck

/**
 * External dependencies
 */
import { useEffect } from 'preact/hooks';
import { effect } from '@preact/signals';

const afterNextFrame = ( callback ) => {
	return new Promise( ( resolve ) => {
		const done = () => {
			clearTimeout( timeout );
			window.cancelAnimationFrame( raf );
			setTimeout( () => {
				callback();
				resolve();
			} );
		};
		const timeout = setTimeout( done, 100 );
		const raf = window.requestAnimationFrame( done );
	} );
};

// Using the mangled properties:
// this.c: this._callback
// this.x: this._compute
// https://github.com/preactjs/signals/blob/main/mangle.json
function createFlusher( compute, notify ) {
	let flush;
	const dispose = effect( function () {
		flush = this.c.bind( this );
		this.x = compute;
		this.c = notify;
		return compute();
	} );
	return { flush, dispose };
}

// Version of `useSignalEffect` with a `useEffect`-like execution. This hook
// implementation comes from this PR, but we added short-cirtuiting to avoid
// infinite loops: https://github.com/preactjs/signals/pull/290
export function useSignalEffect( callback ) {
	useEffect( () => {
		let eff = null;
		let isExecuting = false;
		const notify = async () => {
			if ( eff && ! isExecuting ) {
				isExecuting = true;
				await afterNextFrame( eff.flush );
				isExecuting = false;
			}
		};
		eff = createFlusher( callback, notify );
		return eff.dispose;
	}, [] );
}

// For wrapperless hydration.
// See https://gist.github.com/developit/f4c67a2ede71dc2fab7f357f39cff28c
export const createRootFragment = ( parent, replaceNode ) => {
	replaceNode = [].concat( replaceNode );
	const s = replaceNode[ replaceNode.length - 1 ].nextSibling;
	function insert( c, r ) {
		parent.insertBefore( c, r || s );
	}
	return ( parent.__k = {
		nodeType: 1,
		parentNode: parent,
		firstChild: replaceNode[ 0 ],
		childNodes: replaceNode,
		insertBefore: insert,
		appendChild: insert,
		removeChild( c ) {
			parent.removeChild( c );
		},
	} );
};