There is no specification on recursive callbacks, e.g what happens if someone does

before :test_method :before1
before :before1 :before2

? If anything this kata is like a toy model: only works on a handful of very tiny examples, and not ready for any real world use.

Looks like secret tests are working differently: main class is not unloaded each time.

The most confusing is

The return value of the method is changed based on the registered callback

I've payed a lot of time to understande expected behavior from tests. Please describe it more accurate inside Instructoins.

Duplicate of https://www.codewars.com/kata/custom-sort-function