This does not preseve whitespace.
" this is wrong" should arguably still include a leading space (as said by babakgh)
"this [space space space] is wrong" should arguably still have multiple spaces between 'this' and 'is'
EDIT: Aparently codewars also doesnt preserve multiple whitespace even in code blocks, but hopefully its clear what I mean

Fails with this " this is wrong "

test this:

I say "go"

It won't work

it's a very neat and idiomatic code but as the pattern you capitalize is defined in split, it is not robust nor flexible at all.

Then you displays a validation error until the user types without any errors.

what if space symbol is missed by a mistake, like: "No body really cares,what are you thinking about."

Are "Best Practices" just the top Google result for a properly asked question? [serious]

Need more specific explanation