Function debounce

epicshop/fix-watch.js:35–43

* Simple debounce implementation

(fn, delay)

 * Simple debounce implementation
 */
function debounce(fn, delay) {
	let timer = null
	return (...args) => {
		if (timer) clearTimeout(timer)
		timer = setTimeout(() => {
			fn(...args)
		}, delay)
	}
}

let running = false