жест

loser

ugly, but cool at the same time

loser

loser

I provided even more detailed description, can you check it please

Check out how native js String.prototype.indexOf method works, it can convert an array to string, from [-1, -2, -3] to -1,-2,-3 or number to string before trying to find an index.

Actually the same thing for booleans, what will happen with true + "", right 'true'

I provided a detailed description to the edge cases

Should be fixed, can you check it again

I will check

This is so short lmao, only 45 bytes

why this kata is 5kyu

Hm, this is the first variant of my solution

I'm proud of my solution, lmfao

People often use them where they shouldn't, unless it's a callback.
But this is more my preference