feat(i18n): add native Lunaria key merging

CONTRIBUTING.md

@@ -483,17 +483,8 @@ To add a new locale:
    },
    ```
 
-4. Copy your translation file to `lunaria/files/` for translation tracking:
-
-   ```bash
-   cp i18n/locales/uk-UA.json lunaria/files/uk-UA.json
-   ```
-
-   > ⚠**Important:**
-   > This file must be committed. Lunaria uses git history to track translation progress, so the build will fail if this file is missing.
-
-5. If the language is `right-to-left`, add `dir: 'rtl'` (see `ar-EG` in config for example)
-6. If the language requires special pluralization rules, add a `pluralRule` callback (see `ar-EG` or `ru-RU` in config for examples)
+4. If the language is `right-to-left`, add `dir: 'rtl'` (see `ar-EG` in config for example)
+5. If the language requires special pluralization rules, add a `pluralRule` callback (see `ar-EG` or `ru-RU` in config for examples)
 
 Check [Pluralization rule callback](https://vue-i18n.intlify.dev/guide/essentials/pluralization#custom-pluralization) and [Plural Rules](https://cldr.unicode.org/index/cldr-spec/plural-rules#TOC-Determining-Plural-Categories) for more info.
 

config/i18n.ts

@@ -350,8 +350,6 @@ const locales: (LocaleObjectData | (Omit<LocaleObjectData, 'code'> & { code: str
   },
 ]
 
-const lunariaJSONFiles: Record<string, string> = {}
-
 function buildLocales() {
   const useLocales = Object.values(locales).reduce((acc, data) => {
     const locales = countryLocaleVariants[data.code]
@@ -363,12 +361,10 @@ function buildLocales() {
           name: l.name,
           files: [data.file as string, `${l.code}.json`],
         }
-        lunariaJSONFiles[l.code] = l.country ? (data.file as string) : `${l.code}.json`
         delete entry.file
         acc.push(entry)
       })
     } else {
-      lunariaJSONFiles[data.code] = data.file as string
       acc.push(data as LocaleObjectData)
     }
     return acc
@@ -379,8 +375,6 @@ function buildLocales() {
 
 export const currentLocales = buildLocales()
 
-export { lunariaJSONFiles }
-
 export const datetimeFormats = Object.values(currentLocales).reduce((acc, data) => {
   const dateTimeFormats = data.dateTimeFormats
   if (dateTimeFormats) {

lunaria.config.ts

@@ -1,17 +1,78 @@
 import { defineConfig } from '@lunariajs/core/config'
-import { locales, sourceLocale } from './lunaria/prepare-json-files.ts'
+import type { Locale, Merge } from '@lunariajs/core'
+import { currentLocales, countryLocaleVariants } from './config/i18n.ts'
+
+// The source locale is `en` (en.json contains all reference translation keys).
+// Country variants like `en-US` inherit from `en` via the merge config.
+const sourceLocale: Locale = { label: 'English', lang: 'en' }
+
+// Build the list of Lunaria locales from currentLocales.
+// currentLocales has expanded codes (en-US, en-GB, ar-EG, es-ES, es-419, etc.)
+// but NOT the base codes (ar, es) that the variants inherit from.
+// We need to add those base codes as Lunaria locales too, so they can be
+// referenced in the merge config and tracked independently.
+const localeSet = new Set<string>()
+const locales: Locale[] = []
+
+for (const l of currentLocales) {
+  if (l.code === sourceLocale.lang || !l.name) continue
+  if (!localeSet.has(l.code)) {
+    localeSet.add(l.code)
+    locales.push({ label: l.name, lang: l.code })
+  }
+}
+
+// Add base language codes (ar, es, etc.) that aren't already in the list.
+// These are the keys of countryLocaleVariants that aren't the source locale.
+for (const baseLang of Object.keys(countryLocaleVariants)) {
+  if (baseLang === sourceLocale.lang) continue
+  if (!localeSet.has(baseLang)) {
+    // Use the first variant's name or the base code as label
+    const variants = countryLocaleVariants[baseLang]!
+    const label = variants[0]?.name ?? baseLang
+    localeSet.add(baseLang)
+    locales.push({ label, lang: baseLang })
+  }
+}
+
+if (locales.length === 0) {
+  throw new Error('No locales found besides source locale')
+}
+
+// Build merge config from countryLocaleVariants:
+// Each variant locale merges keys from its base locale, so keys present in
+// the base file count as covered for the variant.
+// e.g. { 'en-US': ['en'], 'en-GB': ['en'], 'ar-EG': ['ar'], 'es-ES': ['es'], 'es-419': ['es'] }
+const merge: Merge = {}
+for (const [baseLang, variants] of Object.entries(countryLocaleVariants)) {
+  for (const variant of variants) {
+    // Each variant merges from its base language and (if not the source) implicitly
+    // from the source via normal Lunaria tracking.
+    const existing = merge[variant.code]
+    if (existing) {
+      existing.push(baseLang)
+    } else {
+      merge[variant.code] = [baseLang]
+    }
+  }
+}
 
 export default defineConfig({
   repository: {
     name: 'npmx-dev/npmx.dev',
   },
   sourceLocale,
-  locales,
+  locales: locales as [Locale, ...Locale[]],
   files: [
     {
-      include: ['lunaria/files/en-US.json'],
-      pattern: 'lunaria/files/@lang.json',
+      include: ['i18n/locales/en.json'],
+      pattern: 'i18n/locales/@lang.json',
       type: 'dictionary',
+      merge,
+      optionalKeys: {
+        $schema: true,
+        vacations: true,
+      },
     },
   ],
   tracking: {