In my opinion, using 'x' instead of 'i' in the for loop would improve readability and understanding for someone only taking a quick glance at this code.

The description doesn't mention what to do when the volume is already divisible by 3

The description doesn't mention what to do when the volume is already divisible by 3

done

done

Random tests added.

Fixed.

approved.

Ah, yes! I missed "lower than". Sorry!

The other kata had a problem there, but this one states in the description

The music can't go lower than 0 volume on this plane of existance.

which lead me to believe 0 was acceptable.

You're right - the simplest solution is not the best solution.

Better to fix the testing.

I'd rather suggest to keep the description as is, this time, and make a slight update in the kata iteslf. It'd be a bit more interesting, I'd say. ;) (not that it's not currently, but the slight shift in the logic is interesting, imo)

Would a zero increase still be an increase? Is 0 a perfectly good number, or not? Not going there .. :P

A slight description update would be the simplest solution, I'd think. Do you have a suggestion for that?

There is also this test:

input=0 -> Test Passed: Value == 0

That contradicts this:

The music should still be audible (0 and below are not going to work well at drowning out your coworkers.)