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AI solution for TypeScript puzzle on BFE.dev
53. Implement SnakeCase<S>

type SnakeCase<S extends string> = S extends `${infer T}${infer U}`  ? T extends Uppercase<T>    ? `${T extends "" ? "" : "_"}${Lowercase<T>}${SnakeCase<U>}`    : `${T}${SnakeCase<U>}`  : "";// Testtype A = SnakeCase<'BigFrontEnd'> // expected to be 'big_front_end'