Why we need await Promise.resolve() in enqueue

[zingxy]

(async () => {
	// This function needs to wait until the next microtask before comparing
	// `activeCount` to `concurrency`, because `activeCount` is updated asynchronously
	// when the run function is dequeued and called. The comparison in the if-statement
	// needs to happen asynchronously as well to get an up-to-date value for `activeCount`.
	await Promise.resolve(); 

	if (activeCount < concurrency && queue.size > 0) {
		queue.dequeue()();
	}
})();

Can you give me some concrete example? Thank you!

[sindresorhus]

#28