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TypeScript Support

i18n-tiny is built with TypeScript and provides excellent type safety for your translations.

Type-Safe Message Resolution​

When you define your i18n instance using define, the types are automatically inferred from your message objects.

// i18n.ts
const messages = {
  en: {
    welcome: "Welcome, {name}!"
  },
  ja: {
    welcome: "ようこそ、{name}さん！"
  }
}

export const { getTranslations } = define({ messages })

// Usage
const t = getTranslations('en')

t('welcome', { name: 'John' }) // Valid
t('invalid') // TypeScript Error: Argument of type '"invalid"' is not assignable...
t('welcome') // TypeScript Error: Property 'name' is missing...

Astro Locals Type​

For type-safe access to Astro.locals.locale (when using SSR Rewrite Mode), add the type reference to your project's src/env.d.ts:

/// <reference types="@i18n-tiny/astro/locals" />

This provides types for:

  • Astro.locals.locale - Current locale string
  • Astro.locals.locales - Array of supported locales
  • Astro.locals.originalPathname - Original pathname (before rewrite)