After upgrading from 0.6.0 to 0.7.0 this code no longer works:

cookie.serialize('myCookie', 'some content', {
  domain: '.localhost',
  httpOnly: true,
  maxAge: 2147483647,
  path: '/',
  sameSite: 'lax',
  secure: true
});

This now throws option domain is invalid.

According RFC6265 Section 4.1.2.3 a leading . (dot) should be allowed for targeting subdomains. Am I doing something wrong, or is this a possible 0.7.0 bug?