happy-dom/src/fetch/utilities/FetchCORSUtility.ts

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

import { URL } from 'url';

/**
 * Fetch CORS utility.
 */
export default class FetchCORSUtility {
	/**
	 * Validates request headers.
	 *
	 * @param originURL Origin URL.
	 * @param targetURL Target URL.
	 */
	public static isCORS(originURL: URL | string, targetURL: URL | string): boolean {
		originURL = typeof originURL === 'string' ? new URL(<string>originURL) : <URL>originURL;
		targetURL = typeof targetURL === 'string' ? new URL(<string>targetURL) : <URL>targetURL;

		if (targetURL.protocol === 'about:' || targetURL.protocol === 'javascript:') {
			return false;
		}

		return (
			(originURL.hostname !== targetURL.hostname &&
				!originURL.hostname.endsWith(targetURL.hostname)) ||
			originURL.protocol !== targetURL.protocol
		);
	}
}