audio.js

(function () {
	// An array of all contexts to resume on the page
	const audioContextList = [];

	// An array of various user interaction events we should listen for
	const userInputEventNames = [
		'click',
		'contextmenu',
		'auxclick',
		'dblclick',
		'mousedown',
		'mouseup',
		'pointerup',
		'touchend',
		'keydown',
		'keyup',
	];

	// A proxy object to intercept AudioContexts and
	// add them to the array for tracking and resuming later
	self.AudioContext = new Proxy(self.AudioContext, {
		construct(target, args) {
			const result = new target(...args);
			audioContextList.push(result);
			return result;
		},
	});

	// To resume all AudioContexts being tracked
	function resumeAllContexts(event) {
		let count = 0;

		audioContextList.forEach(context => {
			if (context.state !== 'running') {
				context.resume();
			} else {
				count++;
			}
		});

		// If all the AudioContexts have now resumed then we
		// unbind all the event listeners from the page to prevent
		// unnecessary resume attempts
		if (count == audioContextList.length) {
			userInputEventNames.forEach(eventName => {
				document.removeEventListener(eventName, resumeAllContexts);
			});
		}
	}

	// We bind the resume function for each user interaction
	// event on the page
	userInputEventNames.forEach(eventName => {
		document.addEventListener(eventName, resumeAllContexts);
	});
})();