He will never answer you, that's a deleted account.

@user9240328 how did you figure that out?

I've edited the test suite to enable Node v12, and your code seems to work with Node v12 but not with any earlier versions.

I think the problem is that the way you're sorting, you're actually getting the last available substring.

Hi, when there are multiple solutions, you code doesn't necessarily return the one that appears first.

I'm not too familiar with JS, but maybe Array.prototype.sort() isn't stable.

Hi,

not an issue. Not even a question, seemingly...

hint: read carefully the specs / read this

closing

That's because your code fails with empty orders. I'm not sure if that input is invalid or not, but you could fix your code to pass it.