Type-safety for JSON translations (TypeScript)

i18n.types.ts

import * as error from './cs/error.json';
/*
// Content of a "./cs/error.json" file
{
  "general": {
    "unexpected": "Došlo k neočekávané chybě."
  },
  "unauthorized": {
    "token": "Váš přístup byl zamítnut, nevalidní token."
  }
}
*/

type Prev = [never, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...0[]];

type PathsWithStringValue<T, D extends number = 10> = [D] extends [never]
  ? never
  : T extends string
  ? []
  : {
      [K in Extract<keyof T, string>]: [K, ...PathsWithStringValue<T[K], Prev[D]>];
    }[Extract<keyof T, string>];

type Join<T extends string[], D extends string> = T extends []
  ? never
  : T extends [infer F]
  ? F
  : T extends [infer F, ...infer R]
  ? F extends string
    ? `${F}${D}${Join<Extract<R, string[]>, D>}`
    : never
  : string;

type DottedStringPaths<T> = Join<PathsWithStringValue<T>, '.'>;

export type ErrorTranslationPath = `error.${DottedStringPaths<typeof error>}`;

let transErrorId: ErrorTranslationPath;
transErrorId = 'error.general.unexpected' // OK
transErrorId = 'error.general' // Error, `general` is not a string value
transErrorId = 'error.unauthorized' // Error, `unauthorized` is not a string value
transErrorId = 'error.unauthorized.token' // OK