Javascript: getElementByXPath

function getElementByXPath(path, context=null, _document=undefined) {
	if( _document === undefined ) _document = document;
	let res = document.evaluate(path, _document, context, XPathResult.FIRST_ORDERED_NODE_TYPE);
	if( !res ) return null;
	return res.singleNodeValue;
}

function getTextByXPath(path, context=null, _document=undefined) {
	let e = getElementByXPath(path, context, _document);
	if( !e ) return undefined;
	return e.textContent;
}

function getTextByQuerySelector(selector) {
	let e = document.querySelector(selector);
	if( !e ) return undefined;
	return e.textContent;
}