Function assert

test/data/jquery-3.7.1.js:978–995

* Support testing using an element * @param {Function} fn Passed the created element and returns a boolean result

( fn )

 * @param {Function} fn Passed the created element and returns a boolean result
 */
function assert( fn ) {
	var el = document.createElement( "fieldset" );

	try {
		return !!fn( el );
	} catch ( e ) {
		return false;
	} finally {

		// Remove from its parent by default
		if ( el.parentNode ) {
			el.parentNode.removeChild( el );
		}

		// release memory in IE
		el = null;
	}
}

/**
 * Returns a function to use in pseudos for input types