take-nested.ts

import { context, Fn, noop, top, wrap } from '@reatom/core';


function takeNested(cb: Fn) {
	const frame = top();

	return new Promise<void>((resolve, reject) => {
		let i = 1;

		const check = () => {
			if (i === 0) {
				resolve();
			}

			if (--i === 0) Promise.resolve().then(check);
		};

		const { pushQueue } = frame.root;

		frame.root.pushQueue = (cb: Fn, queue) => {
			pushQueue.call(
				frame.root,
				() => {
					const result = cb();
					if (result instanceof Promise) {
						++i;
						result.finally(check).catch(noop);
					}
					return result;
				},
				queue,
			);
		};

		const result = frame.run(cb);

		check();

		return result;
	});
}