Note: for this kata y isn't considered a vowel.

Not a kata issue. The problem isn't the environment where you test your code, you didn't follow the instructions.

my solution actually works when i test same text in browser but in codewars it doesnt

в задании надо найти гласные английского языка. Вот они "aeiou"

у меня вопрос, а как найти гласную в алфавите любого языка, нам неизаестного, где мы не можем на память указать все гласные?

This kata was decided to stay.

This kata is a subject to deduplication process here: https://github.com/codewars/content-issues/issues/230.
Please join the discussion to help us identify duplicate kata and retire them.

I feel like it would make the result look nicer if you required no whitespace at the beginning or end. For example, the string "I hate you" currently returns " ht y", but it might be nice to return "ht y" instead. Thoughts?

I think the function argument itself provides a hint to solve this problem.

Note: for this kata y isn't considered a vowel.

No.

'y' doesn't count as a vowel?

This kata was decided to stay

Agree with you bro, just practise until you find your way.

that's normal,

Approved.

Why do I forget about regex?