fails to extract with path

extractDomain(["mother.com/q/s"])

Output should be: mother.com but instead it is mother.com/q/s.

I understand your issue here, but this is not a complete URL.

As described in the readme: https://developer.mozilla.org/en-US/docs/Learn/Common_questions/Web_mechanics/What_is_a_URL

However, of course it would be nice to support a case like this as well, so I will keep the issue open.