i18n-ts-with-namespaces.ts

i18n-ts-with-namespaces.ts

import type { Paths, I18n, Translate } from "next-translate"

type Tail<T> = T extends [unknown, ...infer Rest] ? Rest : never

export type TranslationsKeys = {
  common: Paths<typeof import("./locales/en/common.json")>
  ["feat-analytics"]: Paths<typeof import("./locales/en/feat-analytics.json")>
  ["feat-participate"]: Paths<
    typeof import("./locales/en/feat-participate.json")
  >
  ["feat-results"]: Paths<typeof import("./locales/en/feat-results.json")>
}

type NamespacedTranslationKeys = {
  [Namespace in keyof TranslationsKeys]: `${Namespace}:${TranslationsKeys[Namespace]}`
}[keyof TranslationsKeys]

export type TypeSafeTranslate<Namespace extends keyof TranslationsKeys> = {
  t: {
    (
      key: TranslationsKeys[Namespace] | NamespacedTranslationKeys,
      ...rest: Tail<Parameters<Translate>>
    ): string
    <T extends string>(template: TemplateStringsArray): string
  }
} & Omit<I18n, "t">

declare module "next-translate/useTranslation" {
  export default function useTranslation<
    Namespace extends keyof TranslationsKeys,
  >(namespace: Namespace): TypeSafeTranslate<Namespace>
}