Type Definitions

Complete type reference for i18n-at.

Core Types

MessageNode

interface MessageNode {
  [key: string]: string | MessageNode;
}

Base interface for message structure.

Messages

type Messages<T extends MessageNode, TLocales extends string = string> = {
  [L in TLocales]: T;
};

Type for defining messages across multiple locales.

TranslateFn

type TranslateFn<K extends string = string> = (
  key: K | string,
  params?: Record<string, string | number>
) => string;

Function type for translating messages.

ExtractLocaleMessage

type ExtractLocaleMessage<
  TMessages extends Messages<MessageNode, string>,
  TLocale extends string
> = TLocale extends keyof TMessages ? TMessages[TLocale] : never;

Extracts message type for a specific locale.

Configuration Types

LocaleConfig

interface LocaleConfig {
  name: string;
  direction?: "ltr" | "rtl";
  dateFormat?: string;
}

Configuration for a single locale.

I18nConfig

interface I18nConfig<TLocales extends Record<string, LocaleConfig>> {
  locales: TLocales;
  defaultLocale: keyof TLocales;
  fallbackLocale?: keyof TLocales;
  interpolationFormat?: InterpolationFormat;
}

Complete i18n configuration.

InterpolationFormat

type InterpolationFormat = "none" | "intl" | "legacy" | "double";

Supported interpolation formats.

ExtractLocales

type ExtractLocales<T> = T extends I18nConfig<infer U> ? keyof U : never;

Extracts locale union from configuration.

ExtractDefaultLocale

type ExtractDefaultLocale<T> = T extends I18nConfig<infer U>
  ? T["defaultLocale"]
  : never;

Extracts default locale from configuration.

ExtractConfigLocales

type ExtractConfigLocales<T> = T extends ReturnType<
  typeof defineI18nConfig<infer U extends Record<string, LocaleConfig>>
>
  ? keyof U
  : never;

Extracts locale union from defineI18nConfig result.