camelized-type.ts

type CamelizeString<T extends PropertyKey> = T extends string
  ? string extends T
    ? string
    : T extends `${infer F}_${infer R}`
    ? `${F}${Capitalize<CamelizeString<R>>}`
    : string extends T
    ? string
    : T extends `${infer F}-${infer R}`
    ? `${F}${Capitalize<CamelizeString<R>>}`
    : T
  : T;

type Camelize<T> = { [K in keyof T as CamelizeString<K>]: T[K] };
type Camelized = Camelize<{'kebab-case': string, 'snake_case': string}