Javascript URLSearchParams does not encode query parameters

let url = new URL('https://example.com/?a=b ~');
console.log(url.href, url.toString()); // "https://example.com/?a=b%20~"
// output is instead: "https://example.com/?a=b ~"
 
url = new URL('https://google.com/search');
url.searchParams.set('q', 'test me!'); // added parameter with a space and !
console.log(url.href, url.toString()); // param is not even added?!