nodejs url.resolve() bug

url.js

> var url = require("url");
undefined
> var u = url.parse("https://foo.tld");
undefined
> u
Url {
  protocol: 'https:',
  slashes: true,
  auth: null,
  host: 'foo.tld',
  port: null,
  hostname: 'foo.tld',
  hash: null,
  search: null,
  query: null,
  pathname: '/',
  path: '/',
  href: 'https://foo.tld/' }
> var v = url.parse("wss://foo.tld");
undefined
> v
Url {
  protocol: 'wss:',
  slashes: true,
  auth: null,
  host: 'foo.tld',
  port: null,
  hostname: 'foo.tld',
  hash: null,
  search: null,
  query: null,
  pathname: null,
  path: null,
  href: 'wss://foo.tld' }
> url.format(u);
'https://foo.tld/'
> url.format(v);
'wss://foo.tld'
> url.resolve(url.format(u), 'bar');
'https://foo.tld/bar'
> url.resolve(url.format(v), 'bar');
'wss://bar'