It's not one you'd ever use in practice (I know of no use at least). It's pretty simple to implement given a short description though, so it can be seen as kind of an "advanced" fizzbuzz.

If someone just says "hey, implement bubblesort", that's pretty awful though. Then it's just testing your memory and/or gating by people that studied a particular algorithms curriculum. (Though _many_ intro algorithms courses go through sorting and most of those mention bubble sort probably)