setIntervalMonitor.js

const intervals = (() => {
	/**
		setInterval watcher
	**/
	const setIntervalCounter = [];
	const setIntervalMap = {};
	let startTime = Date.now();
	let lastTime = startTime;
	setInterval(() => {
		const now = Date.now();
		if (now > (lastTime + 1000)) {
			const secondsSinceStart = ((now - startTime) / 1000) >>> 0;
			console.info(`I#${secondsSinceStart} - ${setIntervalCounter.length}`);
			lastTime = now;
		}
	}, 1);
	
	const nativeSetInterval = self.setInterval;
	const nativeClearInterval = self.clearInterval;
	self.setInterval = function() {
		const id = nativeSetInterval.apply(this, arguments);
		setIntervalCounter.push(id);
		setIntervalMap[id] = Array.from(arguments);
		return id;
	}
	
	self.clearInterval = id => {
		const index = setIntervalCounter.indexOf(id);
		if (index > -1) {
			setIntervalCounter.splice(index, 1);
			setIntervalMap[id] = null;
		}
		return nativeClearInterval.call(this, id);
	}
	
	return {
		setIntervalCounter,
		setIntervalMap
	};
})();

setTimeoutMonitor.js

(() => {
	/**
		setTimeout watcher
	**/
	let setTimeoutCount = 0;
	let setTimeoutTotalCount = 0;
	let startTime = Date.now();
	let lastTime = startTime;
	setInterval(() => {
		const now = Date.now();
		if (now > (lastTime + 1000)) {
			const secondsSinceStart = ((now - startTime) / 1000) >>> 0;
			console.info(`T#${secondsSinceStart} - ${setTimeoutCount} - avg: ${setTimeoutTotalCount / secondsSinceStart}`);
			lastTime = now;
			setTimeoutCount = 0;
		}
	}, 1);
	
	const nativeSetTimeout = self.setTimeout;
	self.setTimeout = function() {
		setTimeoutCount++;
		setTimeoutTotalCount++;
		return nativeSetTimeout.apply(this, arguments);
	}
})();