Your current code works, so, probably it was a problem with your code and not a kata issue. Closing.

Your code is failing this test:

Test.assertEquals(generateHashtag("code" + " ".repeat(140) + "wars"), "#CodeWars")

I am returning false i str is empty

  if (!str || str.trim() === "") return false;

then why my code further execcute it should return false. however it's working fine in console not here