import type { Equal, Expect } from '@type-challenges/utils' type cases = [ Expect, 'hello'>>, Expect, 'user_name'>>, Expect, 'get_element_by_id'>>, Expect, 'get_element_by_id' | 'get_element_by_class_names'>>, ] type SnakeCase< T extends string, Acc extends string = '', > = T extends `${infer Head}${infer Tail}` ? Head extends Lowercase ? SnakeCase : SnakeCase}`> : Acc ;