I will try. Looking at the number we can see the smallest digit is 1 which appears in the number in several places, at positions 6,7 and 10 using 0 based indexing.
We choose the the last occurence of the minimumal digit to find the smallest number, so we can tranformer the number say to an array or string to using the built in
method lastIndexOf()

Respect!

This kata is really useful!
That this experience will come in handy!
Respect for autor!

Yes! I get it... )
sometimes, you just need to relax the brain)

Shift right (you move every character one position to the right, the rightmost char of the string enters from the left):

niv <- original string
vni (1)
ivn (2)
niv (3)
vni (4)
ivn (5)
niv (6)
vni (7)
ivn (8)
niv (9)
vni (10)

It's like this

Thanks)

That's because fianl number, 18786300289, is smaller than 18786302809. You need to get the smallest number possible, the smallest index is a secondary criterion in case there are multiple ways to get the smallest number.

18786300289 < 18786302809

Add tests with punctuation marks for javaScript!
Several, the so-called smartest solutions)) will not pass them!

thanks)

I just did, it's an empty string.

No, it's not, and next time mark your post as having spoiler content.

At least one character ("" is not valid)

Check that. Your function returns true.