Useful types in typescript

useful.ts

export type CamelCase<S extends string> =
  S extends `${infer P1}_${infer P2}${infer P3}`
    ? `${Lowercase<P1>}${Uppercase<P2>}${CamelCase<P3>}`
    : Lowercase<S>;

export type KeysToCamelCase<T> = {
  [K in keyof T as CamelCase<string & K>]: T[K] extends {}
    ? KeysToCamelCase<T[K]>
    : T[K];
};

export type ValueOf<T> = T[keyof T];