BrowserSync restore scroll position

browsersync-scroll-plugin.js

/* eslint-disable */
// Inspired by https://github.com/BrowserSync/browser-sync/issues/273#issuecomment-57427711
(function ($window, $document, bs) {
	var socket = bs.socket;
	var selector = '[md-scroll-y]';
	var PRE     = "<<BS_START>>";
	var SUF     = "<<BS_END>>";
	var regex   = new RegExp(PRE + "(.+?)" + SUF);
	var saved = {};

	// Listen for the event in other browsers
	socket.on('browser:reload', function (scrollTop) {
		var $elem = $document.querySelector(selector);
		if (!$elem) return;
		var newname = [PRE, JSON.stringify({
				bs: { scroll: { x: 0, y: $elem.scrollTop } }
		}), SUF].join("");
		$window.name = newname;
	});

	try {
		var json = $window.name.match(regex);
		if (json) {
			saved = JSON.parse(json[1]);
		}
	} catch (e) {
		saved = {};
	}

	/**
	* If the JSON was parsed correctly, try to
	* find a scroll property and restore it.
	*/
	if (saved.bs && saved.bs.scroll) {
		var func = setInterval(function () {
			var $elem = $document.querySelector(selector);
			if (!$elem) return;
			$elem.scrollTop = saved.bs.scroll.y;
			clearInterval(func);
		}, 200);
	}

	/**
	* Remove any existing BS json from window.name.
	*/
	$window.name = $window.name.replace(regex, "");

})(window, document, ___browserSync___);