With font.color = white even an ordinary "W" could count as whitespace... Something to remember if you see whitespace with an extraordinary width out there in the wild...

The \s character class in JavaScript regular expressions includes 25 characters. I don’t know if that perfectly matches the Unicode list of 25 characters, but it does make identifying white space simplistic.

White space characters are challenging to differentiate in human readable text, but JavaScript makes that perfectly clear to humans by splitting a string on every character, which is helpful for debugging.