From 0d7f35ad4d2ae202d9461ecb968b5a4eb52c09ab Mon Sep 17 00:00:00 2001
From: LEGO Technix <109212476+lego-technix@users.noreply.github.com>
Date: Wed, 2 Oct 2024 14:24:27 +0200
Subject: [PATCH] feat(shared): add new getBestMatchingLocaleName function

---
 shared/composables/useLocaleCookie.ts         | 17 +++++++
 .../tests/composables/useLocaleCookie.test.ts | 44 +++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/shared/composables/useLocaleCookie.ts b/shared/composables/useLocaleCookie.ts
index 213b63012..805695442 100644
--- a/shared/composables/useLocaleCookie.ts
+++ b/shared/composables/useLocaleCookie.ts
@@ -3,9 +3,12 @@ const LOCALE_COOKIE_NAME = 'locale';
 export default function useLocaleCookie() {
   const appConfig = useAppConfig();
   const runtimeConfig = useRuntimeConfig();
+
   const domainFrUrl = new URL(appConfig.domainFr);
   const domainOrgUrl = new URL(appConfig.domainOrg);
 
+  const availableLocaleNames = runtimeConfig.public.availableLocaleNames as Array<string>;
+
   const previousLocaleCookieToDelete = useCookie(LOCALE_COOKIE_NAME, {
     maxAge: 31536000, // 1 year
     sameSite: 'strict',
@@ -29,8 +32,22 @@ export default function useLocaleCookie() {
     if (callback) callback();
   }
 
+  function getBestMatchingLocaleName(localeName: string) {
+    if (availableLocaleNames.includes(localeName)) {
+      return localeName;
+    }
+
+    const languageLocaleName = new Intl.Locale(localeName).language;
+    if (availableLocaleNames.includes(languageLocaleName)) {
+      return languageLocaleName;
+    }
+
+    return availableLocaleNames[0];
+  }
+
   return {
     localeCookie,
     setLocaleCookie,
+    getBestMatchingLocaleName,
   };
 }
diff --git a/shared/tests/composables/useLocaleCookie.test.ts b/shared/tests/composables/useLocaleCookie.test.ts
index a672448cc..e1b7189ab 100644
--- a/shared/tests/composables/useLocaleCookie.test.ts
+++ b/shared/tests/composables/useLocaleCookie.test.ts
@@ -3,6 +3,8 @@ import { mockNuxtImport } from '@nuxt/test-utils/runtime';
 
 import useLocaleCookie from '../../composables/useLocaleCookie';
 
+const availableLocaleNames = ['en', 'fr', 'fr-fr'];
+
 mockNuxtImport('useCookie', () => {
   return () => ({
     value: '',
@@ -18,6 +20,7 @@ mockNuxtImport('useRuntimeConfig', () => {
   return () => ({
     public: {
       siteDomain: 'ORG',
+      availableLocaleNames,
     },
   });
 });
@@ -74,4 +77,45 @@ describe('#useLocaleCookie', () => {
       });
     });
   });
+
+  describe('getBestMatchingLocaleName', () => {
+    describe('when wanted locale is available', () => {
+      test('returns the same locale name', () => {
+        // given
+        const { getBestMatchingLocaleName } = useLocaleCookie();
+
+        // when
+        const matchingLocaleName = getBestMatchingLocaleName('fr-fr');
+
+        // then
+        expect(matchingLocaleName).toEqual('fr-fr');
+      });
+    });
+
+    describe('when wanted locale is unavailable but an available locale with same language is', () => {
+      test('returns the same locale name', () => {
+        // given
+        const { getBestMatchingLocaleName } = useLocaleCookie();
+
+        // when
+        const matchingLocaleName = getBestMatchingLocaleName('fr-be');
+
+        // then
+        expect(matchingLocaleName).toEqual('fr');
+      });
+    });
+
+    describe('when wanted locale is unavailable and no available locale with same language is', () => {
+      test('returns the first available locale name', () => {
+        // given
+        const { getBestMatchingLocaleName } = useLocaleCookie();
+
+        // when
+        const matchingLocaleName = getBestMatchingLocaleName('nl-be');
+
+        // then
+        expect(matchingLocaleName).toEqual('en');
+      });
+    });
+  });
 });