Scroll like a king

gistfile1.txt

module.exports = function domUpdate( app ): Object {
	if ( typeof app !== 'object' ) { return; }

	// recursion recursion recursion
	// we pass in the FSB stuff to make sure we're
	// using the latest cache stuff
	raf(() => {
		return app.domUpdate( app );
	});

	let cache: Object = app.cache;

	// dont move me. i go before the early return.
	// visual perf gets killed if i move
	cache.currScroll = window.pageYOffset + 60;

	// exit early if possible and do no work (if not moving basically)
	if ( cache.currScroll === cache.prevScroll ) {
		return;
	}
	
	/*
		do 
		your 
		logic 
		here
	*/
	
	cache.prevScroll = window.pageYOffset + 60;
	return cache;
};