Converts camelCase key in interface to snake_case key

typescript-camel-case-object-keys-to-snake-case

// Adapted from: https://stackoverflow.com/a/65642944/6502003
type CamelToSnake<T extends string, P extends string = ''> = string extends T
  ? string
  : T extends `${infer K}${infer R}`
  ? CamelToSnake<R, `${P}${K extends Lowercase<K> ? '' : '_'}${Lowercase<K>}`>
  : P

/**
 * Converts camelCase key in interface to snake_case key
 * Example:
 *     type Name = CamelToSnakeCaseKeys<{ firstName: 'Ryan' }> // { first_name: 'Ryan' }
 */
export type CamelToSnakeCaseKeys<Type> = Type extends object
  ? {
      [Property in keyof Type as CamelToSnake<
        string & Property
      >]: CamelToSnakeCaseKeys<Type[Property]>
    }
  : Type