From 4e5ae5fcaba7dde0d65a87da3aeaf32d8bb1a401 Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Sat, 19 Sep 2026 09:58:42 +0200
Subject: [PATCH] Localize default account name created during user
 registration

---
 apps/api/src/app/user/user.controller.ts    |  2 +-
 apps/api/src/app/user/user.service.ts       |  4 ++--
 apps/api/src/helper/language.helper.spec.ts |  9 +++++++++
 apps/api/src/helper/language.helper.ts      | 20 ++++++++++++++------
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/apps/api/src/app/user/user.controller.ts b/apps/api/src/app/user/user.controller.ts
index 00939c9b49..ae9e7d680b 100644
--- a/apps/api/src/app/user/user.controller.ts
+++ b/apps/api/src/app/user/user.controller.ts
@@ -161,7 +161,7 @@ export class UserController {
 
     const { accessToken, id, role } = await this.userService.createUser({
       data: {},
-      languageCode: data?.languageCode
+      languageCode: data.languageCode
     });
 
     return {
diff --git a/apps/api/src/app/user/user.service.ts b/apps/api/src/app/user/user.service.ts
index d85060cb8d..dae4463d23 100644
--- a/apps/api/src/app/user/user.service.ts
+++ b/apps/api/src/app/user/user.service.ts
@@ -716,8 +716,8 @@ export class UserService {
           create: {
             currency: DEFAULT_CURRENCY,
             name: this.i18nService.getTranslation({
-              languageCode: getSupportedLanguageCode(languageCode),
-              id: 'myAccount'
+              id: 'myAccount',
+              languageCode: getSupportedLanguageCode(languageCode)
             })
           }
         },
diff --git a/apps/api/src/helper/language.helper.spec.ts b/apps/api/src/helper/language.helper.spec.ts
index 0d7a39956d..f3159b98ac 100644
--- a/apps/api/src/helper/language.helper.spec.ts
+++ b/apps/api/src/helper/language.helper.spec.ts
@@ -24,8 +24,17 @@ describe('getSupportedLanguageCode', () => {
     expect(getSupportedLanguageCode('de')).toEqual('de');
   });
 
+  it('should ignore the region subtag', () => {
+    expect(getSupportedLanguageCode('de-CH')).toEqual('de');
+  });
+
+  it('should ignore the case', () => {
+    expect(getSupportedLanguageCode('DE')).toEqual('de');
+  });
+
   it('should use the default language code if the language is not supported', () => {
     expect(getSupportedLanguageCode()).toEqual(DEFAULT_LANGUAGE_CODE);
+    expect(getSupportedLanguageCode('')).toEqual(DEFAULT_LANGUAGE_CODE);
     expect(getSupportedLanguageCode('xx')).toEqual(DEFAULT_LANGUAGE_CODE);
   });
 });
diff --git a/apps/api/src/helper/language.helper.ts b/apps/api/src/helper/language.helper.ts
index 02942e14ff..29de5147f6 100644
--- a/apps/api/src/helper/language.helper.ts
+++ b/apps/api/src/helper/language.helper.ts
@@ -3,14 +3,22 @@ import {
   SUPPORTED_LANGUAGE_CODES
 } from '@ghostfolio/common/config';
 
-export function getLanguageCodeFromHeader(acceptLanguage?: string): string {
-  const languageCode = acceptLanguage?.split(',')[0].split('-')[0];
+type SupportedLanguageCode = (typeof SUPPORTED_LANGUAGE_CODES)[number];
 
-  return getSupportedLanguageCode(languageCode);
+export function getLanguageCodeFromHeader(
+  acceptLanguage?: string
+): SupportedLanguageCode {
+  return getSupportedLanguageCode(acceptLanguage?.split(',')[0]);
 }
 
-export function getSupportedLanguageCode(languageCode?: string): string {
-  return (SUPPORTED_LANGUAGE_CODES as readonly string[]).includes(languageCode)
-    ? languageCode
+export function getSupportedLanguageCode(
+  languageCode?: string
+): SupportedLanguageCode {
+  const languageCodeToUse = languageCode
+    ?.split('-')[0]
+    .toLowerCase() as SupportedLanguageCode;
+
+  return SUPPORTED_LANGUAGE_CODES.includes(languageCodeToUse)
+    ? languageCodeToUse
     : DEFAULT_LANGUAGE_CODE;
 }