Ruby 3.1 adds subclasses method
By Abhishek on January 21, 2022
Ruby 3.1 adds
Class#subclasses method, which returns an array of subclasses directly inheriting from the
receiver, not including singleton classes.
class Parent; end class ChildA < Parent; end class ChildB < Parent; end class GrandChildA < ChildA; end Parent.subclasses => [ChildA, ChildB] ChildA.subclasses => [GrandChildA] GrandChildA.subclasses => 
Reference #Pull Request