Async Wait for Element

Need to wait for an element to exist before touching it? setTimeout and mutation observers are overkill for most cases. Here’s a simple async loop that checks for the element and resolves when it’s ready. No dependencies. No noise.

function waitForElement(selector) {
	return new Promise(resolve => {
		const observer = new MutationObserver(mutations => {
			if (document.querySelectorAll(selector)) {
				if (document.querySelectorAll(selector).length > 0) {
					resolve(document.querySelectorAll(selector));
					observer.disconnect();
				}
			}
		});

		observer.observe(document.body, {
			childList: true,
			subtree: true
		});
	});
}