From 45437d594af3a0fd3ec70e8c78902d3e467b87a9 Mon Sep 17 00:00:00 2001
From: Bobbie Goede <bobbiegoede@gmail.com>
Date: Mon, 25 Nov 2024 08:44:28 +0100
Subject: [PATCH] fix: i18n locale config type safety (#22)

---
 config/i18n.ts                        | 50 +++++++++++++++++----------
 scripts/prepare-translation-status.ts |  8 +++--
 2 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/config/i18n.ts b/config/i18n.ts
index e51da89e5..d132f17c3 100644
--- a/config/i18n.ts
+++ b/config/i18n.ts
@@ -1,13 +1,16 @@
-import type { DateTimeFormats, NumberFormats, PluralizationRule, PluralizationRules } from '@intlify/core-base'
+import type { DateTimeFormats, Locale, NumberFormats, PluralizationRule, PluralizationRules } from '@intlify/core-base'
 import type { LocaleObject } from '@nuxtjs/i18n'
 
-interface LocaleObjectData extends LocaleObject {
+interface LocaleObjectData<T> extends LocaleObject<T> {
   numberFormats?: NumberFormats
   dateTimeFormats?: DateTimeFormats
   pluralRule?: PluralizationRule
 }
 
-export const countryLocaleVariants: Record<string, (LocaleObjectData & { country?: boolean }) []> = {
+type CountryLocaleVariant = LocaleObjectData<Locale> & { country?: boolean }
+type CountryLocaleVariantConfig = Record<string, CountryLocaleVariant[]>
+
+export const countryLocaleVariants = {
   ar: [
     // ar.json contains ar-EG translations
     // { code: 'ar-DZ', name: 'Arabic (Algeria)' },
@@ -71,17 +74,17 @@ export const countryLocaleVariants: Record<string, (LocaleObjectData & { country
     { country: true, code: 'pt-PT', name: 'Português (Portugal)' },
     { code: 'pt-BR', name: 'Português (Brasil)' },
   ],
-}
+} satisfies CountryLocaleVariantConfig
+
+type LocaleVariantKeys = keyof typeof countryLocaleVariants
 
-const locales: LocaleObjectData[] = [
+const locales: (LocaleObjectData<LocaleVariantKeys> | LocaleObjectData<Locale>)[] = [
   {
-    // @ts-expect-error en used as placeholder
     code: 'en',
     file: 'en.json',
     name: 'English',
   },
   ({
-    // @ts-expect-error ar used as placeholder
     code: 'ar',
     file: 'ar.json',
     name: 'العربية',
@@ -90,7 +93,7 @@ const locales: LocaleObjectData[] = [
       const name = new Intl.PluralRules('ar-EG').select(choice)
       return { zero: 0, one: 1, two: 2, few: 3, many: 4, other: 5 }[name]
     },
-  } satisfies LocaleObjectData),
+  }),
   ({
     code: 'ckb',
     file: 'ckb.json',
@@ -100,7 +103,7 @@ const locales: LocaleObjectData[] = [
       const name = new Intl.PluralRules('ckb').select(choice)
       return { zero: 0, one: 1, two: 2, few: 3, many: 4, other: 5 }[name]
     },
-  } satisfies LocaleObjectData),
+  }),
   ({
     code: 'fa-IR',
     file: 'fa-IR.json',
@@ -110,9 +113,8 @@ const locales: LocaleObjectData[] = [
       const name = new Intl.PluralRules('fa-IR').select(choice)
       return { zero: 0, one: 1, two: 2, few: 3, many: 4, other: 5 }[name]
     },
-  } satisfies LocaleObjectData),
+  }),
   {
-    // @ts-expect-error ca used as placeholder
     code: 'ca',
     file: 'ca.json',
     name: 'Català',
@@ -153,7 +155,6 @@ const locales: LocaleObjectData[] = [
     name: 'Nederlands',
   },
   {
-    // @ts-expect-error es used as placeholder
     code: 'es',
     file: 'es.json',
     name: 'Español',
@@ -207,7 +208,6 @@ const locales: LocaleObjectData[] = [
     },
   },
   {
-    // @ts-expect-error pt used as placeholder
     code: 'pt',
     file: 'pt.json',
     name: 'Português',
@@ -259,12 +259,25 @@ const locales: LocaleObjectData[] = [
   },
 ]
 
+export function isLocaleVariantKey(val: string): val is LocaleVariantKeys {
+  if (val in countryLocaleVariants === false)
+    return false
+
+  return true
+}
+
+function isLocaleVariant(val: LocaleObjectData<LocaleVariantKeys | Locale>): val is LocaleObjectData<LocaleVariantKeys> {
+  if (!isLocaleVariantKey(val.code))
+    return false
+
+  return true
+}
+
 function buildLocales() {
   const useLocales = Object.values(locales).reduce((acc, data) => {
-    const locales = countryLocaleVariants[data.code]
-    if (locales) {
-      locales.forEach((l) => {
-        const entry: LocaleObjectData = {
+    if (isLocaleVariant(data)) {
+      countryLocaleVariants[data.code].forEach((l) => {
+        const entry: LocaleObject = {
           ...data,
           code: l.code,
           name: l.name,
@@ -277,8 +290,9 @@ function buildLocales() {
     else {
       acc.push(data)
     }
+
     return acc
-  }, <LocaleObjectData[]>[])
+  }, <LocaleObject[]>[])
 
   return useLocales.sort((a, b) => a.code.localeCompare(b.code))
 }
diff --git a/scripts/prepare-translation-status.ts b/scripts/prepare-translation-status.ts
index 2adda438e..e75fd52fd 100644
--- a/scripts/prepare-translation-status.ts
+++ b/scripts/prepare-translation-status.ts
@@ -1,12 +1,13 @@
+import type { Locale } from '@intlify/core-base'
 import type { LocaleEntry } from '../docs/types'
 import { Buffer } from 'node:buffer'
 import { readFile, writeFile } from 'node:fs/promises'
 import { createResolver } from '@nuxt/kit'
 import { flatten } from 'flat'
 import type { NimbusTranslationStatus } from '~/types/translation-status'
-import { countryLocaleVariants, currentLocales } from '../config/i18n'
+import { countryLocaleVariants, currentLocales, isLocaleVariantKey } from '../config/i18n'
 
-export const localeData: [code: string, file: string[], title: string][]
+export const localeData: [code: Locale, file: string[], title: string][]
     = currentLocales.map((l: any) => [l.code, l.files ? l.files : [l.file!], l.name ?? l.code])
 
 function merge(src: Record<string, any>, dst: Record<string, any>) {
@@ -79,7 +80,8 @@ async function prepareTranslationStatus() {
   await Promise.all(localeData.filter(l => l[0] !== 'en-US').map(async ([code, file, title]) => {
     console.info(`Comparing ${code}...`, title)
     let useFile = file[file.length - 1]
-    const entry = countryLocaleVariants[file[0].slice(0, file[0].indexOf('.'))]
+    const entryKey = file[0].slice(0, file[0].indexOf('.'))
+    const entry = isLocaleVariantKey(entryKey) ? countryLocaleVariants[entryKey] : undefined
     if (entry) {
       const countryFile = entry.find(e => e.code === code && e.country === true)
       if (countryFile)