@bigfishtv/cockpit/es/utils/isCrossDomain.js

var originAnchor = document.createElement('a');
originAnchor.href = window.location.href;

// from jquery source code
export default function isCrossDomain(url) {
	var urlAnchor = document.createElement('a');

	// Support: IE <=8 - 11, Edge 12 - 15
	// IE throws exception on accessing the href property if url is malformed,
	// e.g. http://example.com:80x/
	try {
		urlAnchor.href = url;

		// Support: IE <=8 - 11 only
		// Anchor's host property isn't correctly set when s.url is relative
		urlAnchor.href = urlAnchor.href;
		return originAnchor.protocol + '//' + originAnchor.host !== urlAnchor.protocol + '//' + urlAnchor.host;
	} catch (e) {
		// If there is an error parsing the URL, assume it is crossDomain,
		// it can be rejected by the transport if it is invalid
		return true;
	}
}