( function () {
	/**
	 * Compares the default Uri host, usually `window.location.host`, and `mw.Uri.host`. Equivalence
	 * tests internal linkage, a mismatch may indicate an external link. Interwiki links are
	 * considered external.
	 *
	 * This function only indicates internal in the sense of being on the same host or not. It has
	 * no knowledge of [[Link]] vs [Link] links.
	 *
	 * On https://meta.wikimedia.org/wiki/Foo, the following links would be considered *internal*
	 * and return `true`:
	 *
	 *     https://meta.wikimedia.org/
	 *     https://meta.wikimedia.org/wiki/Bar
	 *     https://meta.wikimedia.org/w/index.php?title=Bar
	 *
	 * Similarly, the following links would be considered *not* internal and return `false`:
	 *
	 *     https://archive.org/
	 *     https://foo.wikimedia.org/
	 *     https://en.wikipedia.org/
	 *     https://en.wikipedia.org/wiki/Bar
	 *
	 * @param {mw.Uri} uri
	 * @return {boolean}
	 */
	function isInternal( uri ) {
		try {
			// mw.Uri can throw exceptions (T264914, T66884)
			return uri.host === mw.Uri().host;
		} catch ( e ) {
			return false;
		}
	}

	module.exports = {
		isInternal: isInternal
	};
}() );