feat(i18n): strip unused i18n keys (#471)

Co-authored-by: Daniel Roe <[e-mail]>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

.github/workflows/autofix.yml

···
       - name: 📦 Install browsers
         run: pnpm playwright install
 
+      - name: 🌐 Compare translations
+        run: pnpm i18n:check
+
       - name: 🌍 Update lunaria data
         run: pnpm build:lunaria
 

CONTRIBUTING.md

···
 
 Check [Pluralization rule callback](https://vue-i18n.intlify.dev/guide/essentials/pluralization.html#custom-pluralization) for more info.
 
+### Update translation
+
+We track the current progress of translations with [Lunaria](https://lunaria.dev/) on this site: https://i18n.npmx.dev/
+If you see any outdated translations in your language, feel free to update the keys to match then English version.
+
+In order to make sure you have everything up-to-date, you can run:
+
+```bash
+pnpm i18n:check <country-code>
+```
+
+For example to check if all Japanese translation keys are up-to-date, run:
+
+```bash
+pnpm i18n:check ja-JP
+```
+
 #### Country variants (advanced)
 
 Most languages only need a single locale file. Country variants are only needed when you want to support regional differences (e.g., `es-ES` for Spain vs `es-419` for Latin America).

i18n/locales/de-DE.json

···
   "auth": {
     "modal": {
       "title": "Atmosphere",
-      "close": "Schließen",
       "connected_as": "Verbunden als {'@'}{handle}",
       "disconnect": "Verbindung trennen",
       "connect_prompt": "Melde dich bei deinem Atmosphere-Konto an",

lunaria/files/de-DE.json

···
   "auth": {
     "modal": {
       "title": "Atmosphere",
-      "close": "Schließen",
       "connected_as": "Verbunden als {'@'}{handle}",
       "disconnect": "Verbindung trennen",
       "connect_prompt": "Melde dich bei deinem Atmosphere-Konto an",

package.json

···
     "build:lunaria": "node --experimental-transform-types ./lunaria/lunaria.ts",
     "dev": "nuxt dev",
     "dev:docs": "pnpm run --filter npmx-docs dev --port=3001",
+    "i18n:check": "node --experimental-transform-types scripts/compare-translations.ts",
     "knip": "knip",
     "knip:fix": "knip --fix",
     "knip:production": "knip --production",

scripts/compare-translations.ts

···
+import process from 'node:process'
+import { existsSync, readdirSync, readFileSync, writeFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { fileURLToPath } from 'node:url'
+
+const LOCALES_DIRECTORY = fileURLToPath(new URL('../i18n/locales', import.meta.url))
+const REFERENCE_FILE_NAME = 'en.json'
+
+const COLORS = {
+  reset: '\x1b[0m',
+  red: '\x1b[31m',
+  green: '\x1b[32m',
+  yellow: '\x1b[33m',
+  magenta: '\x1b[35m',
+  cyan: '\x1b[36m',
+} as const
+
+type NestedObject = { [key: string]: unknown }
+
+const flattenObject = (obj: NestedObject, prefix = ''): Record<string, unknown> => {
+  return Object.keys(obj).reduce<Record<string, unknown>>((acc, key) => {
+    const propertyPath = prefix ? `${prefix}.${key}` : key
+    const value = obj[key]
+    if (typeof value === 'object' && value !== null && !Array.isArray(value)) {
+      Object.assign(acc, flattenObject(value as NestedObject, propertyPath))
+    } else {
+      acc[propertyPath] = value
+    }
+    return acc
+  }, {})
+}
+
+const loadJson = (filePath: string): NestedObject => {
+  if (!existsSync(filePath)) {
+    console.error(`${COLORS.red}Error: File not found at ${filePath}${COLORS.reset}`)
+    process.exit(1)
+  }
+  return JSON.parse(readFileSync(filePath, 'utf-8')) as NestedObject
+}
+
+const removeKeysFromObject = (obj: NestedObject, keysToRemove: string[]): NestedObject => {
+  const result: NestedObject = {}
+
+  for (const key of Object.keys(obj)) {
+    const value = obj[key]
+
+    // Check if this key or any nested path starting with this key should be removed
+    const shouldRemoveKey = keysToRemove.some(k => k === key || k.startsWith(`${key}.`))
+    const hasNestedRemovals = keysToRemove.some(k => k.startsWith(`${key}.`))
+
+    if (keysToRemove.includes(key)) {
+      // Skip this key entirely
+      continue
+    }
+
+    if (typeof value === 'object' && value !== null && !Array.isArray(value) && hasNestedRemovals) {
+      // Recursively process nested objects
+      const nestedKeysToRemove = keysToRemove
+        .filter(k => k.startsWith(`${key}.`))
+        .map(k => k.slice(key.length + 1))
+      const cleaned = removeKeysFromObject(value as NestedObject, nestedKeysToRemove)
+      // Only add if there are remaining keys
+      if (Object.keys(cleaned).length > 0) {
+        result[key] = cleaned
+      }
+    } else if (!shouldRemoveKey || hasNestedRemovals) {
+      result[key] = value
+    }
+  }
+
+  return result
+}
+
+const logSection = (
+  title: string,
+  keys: string[],
+  color: string,
+  icon: string,
+  emptyMessage: string,
+): void => {
+  console.log(`\n${color}${icon} ${title}${COLORS.reset}`)
+  if (keys.length === 0) {
+    console.log(`  ${COLORS.green}${emptyMessage}${COLORS.reset}`)
+    return
+  }
+  keys.forEach(key => console.log(`  - ${key}`))
+}
+
+const processLocale = (
+  localeFile: string,
+  referenceKeys: string[],
+): { missing: string[]; removed: string[] } => {
+  const filePath = join(LOCALES_DIRECTORY, localeFile)
+  const content = loadJson(filePath)
+  const flattenedKeys = Object.keys(flattenObject(content))
+
+  const missingKeys = referenceKeys.filter(key => !flattenedKeys.includes(key))
+  const extraneousKeys = flattenedKeys.filter(key => !referenceKeys.includes(key))
+
+  if (extraneousKeys.length > 0) {
+    // Remove extraneous keys and write back
+    const cleaned = removeKeysFromObject(content, extraneousKeys)
+    writeFileSync(filePath, JSON.stringify(cleaned, null, 2) + '\n', 'utf-8')
+  }
+
+  return { missing: missingKeys, removed: extraneousKeys }
+}
+
+const runSingleLocale = (locale: string, referenceKeys: string[]): void => {
+  const localeFile = locale.endsWith('.json') ? locale : `${locale}.json`
+  const filePath = join(LOCALES_DIRECTORY, localeFile)
+
+  if (!existsSync(filePath)) {
+    console.error(`${COLORS.red}Error: Locale file not found: ${localeFile}${COLORS.reset}`)
+    process.exit(1)
+  }
+
+  const content = loadJson(filePath)
+  const flattenedKeys = Object.keys(flattenObject(content))
+  const missingKeys = referenceKeys.filter(key => !flattenedKeys.includes(key))
+
+  console.log(`${COLORS.cyan}=== Missing keys for ${localeFile} ===${COLORS.reset}`)
+  console.log(`Reference: ${REFERENCE_FILE_NAME} (${referenceKeys.length} keys)`)
+  console.log(`Target: ${localeFile} (${flattenedKeys.length} keys)`)
+
+  if (missingKeys.length === 0) {
+    console.log(`\n${COLORS.green}No missing keys!${COLORS.reset}\n`)
+  } else {
+    console.log(`\n${COLORS.yellow}Missing ${missingKeys.length} key(s):${COLORS.reset}`)
+    missingKeys.forEach(key => console.log(`  - ${key}`))
+    console.log('')
+  }
+}
+
+const runAllLocales = (referenceKeys: string[]): void => {
+  const localeFiles = readdirSync(LOCALES_DIRECTORY).filter(
+    file => file.endsWith('.json') && file !== REFERENCE_FILE_NAME,
+  )
+
+  console.log(`${COLORS.cyan}=== Translation Audit ===${COLORS.reset}`)
+  console.log(`Reference: ${REFERENCE_FILE_NAME} (${referenceKeys.length} keys)`)
+  console.log(`Checking ${localeFiles.length} locale(s)...`)
+
+  let totalMissing = 0
+  let totalRemoved = 0
+
+  for (const localeFile of localeFiles) {
+    const { missing, removed } = processLocale(localeFile, referenceKeys)
+
+    if (missing.length > 0 || removed.length > 0) {
+      console.log(`\n${COLORS.cyan}--- ${localeFile} ---${COLORS.reset}`)
+
+      if (missing.length > 0) {
+        logSection(
+          'MISSING KEYS (in en.json but not in this locale)',
+          missing,
+          COLORS.yellow,
+          '',
+          '',
+        )
+        totalMissing += missing.length
+      }
+
+      if (removed.length > 0) {
+        logSection(
+          'REMOVED EXTRANEOUS KEYS (were in this locale but not in en.json)',
+          removed,
+          COLORS.magenta,
+          '',
+          '',
+        )
+        totalRemoved += removed.length
+      }
+    }
+  }
+
+  console.log(`\n${COLORS.cyan}=== Summary ===${COLORS.reset}`)
+  if (totalMissing > 0) {
+    console.log(`${COLORS.yellow}  Missing keys across all locales: ${totalMissing}${COLORS.reset}`)
+  }
+  if (totalRemoved > 0) {
+    console.log(`${COLORS.magenta}  Removed extraneous keys: ${totalRemoved}${COLORS.reset}`)
+  }
+  if (totalMissing === 0 && totalRemoved === 0) {
+    console.log(`${COLORS.green}  All locales are in sync!${COLORS.reset}`)
+  }
+  console.log('')
+}
+
+const run = (): void => {
+  const referenceFilePath = join(LOCALES_DIRECTORY, REFERENCE_FILE_NAME)
+  const referenceContent = loadJson(referenceFilePath)
+  const referenceKeys = Object.keys(flattenObject(referenceContent))
+
+  const targetLocale = process.argv[2]
+
+  if (targetLocale) {
+    // Single locale mode: just show missing keys (no modifications)
+    runSingleLocale(targetLocale, referenceKeys)
+  } else {
+    // All locales mode: check all and remove extraneous keys
+    runAllLocales(referenceKeys)
+  }
+}
+
+run()