traceIntervalsAndTimeouts.js

function getStackTrace() {
	let obj = {};
	Error.captureStackTrace(obj, getStackTrace);
	return obj.stack;
}

window.activeFuncs = {};
window.originalSetTimeout = window.setTimeout;
window.originalClearTimeout = window.clearTimeout;
window.originalSetInterval = window.setInterval;
window.originalClearInterval = window.clearInterval;

window.setTimeout = function(func, delay) {
	let id,
		wrapper = () => {
			delete window.activeFuncs['timeout' + id];
			func.apply(window);
		};
	id = window.originalSetTimeout(wrapper, delay);
	if (func) {
		window.activeFuncs['timeout' + id] = getStackTrace();
	}
	return id;
};
window.clearTimeout = function(timerID) {
	window.originalClearTimeout(timerID);
	delete window.activeFuncs['timeout' + timerID];
};
window.setInterval = function(func, delay) {
	let id = window.originalSetInterval(func, delay);
	if (func) {
		window.activeFuncs['interval' + id] = getStackTrace();
	}
	return id;
};
window.clearInterval = function(intervalID) {
	delete window.activeFuncs['interval' + intervalID];
	return window.originalClearInterval(intervalID);
};