From 62eaa0855e18ffa200e010c235a2222d057b9ad2 Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Thu, 15 Oct 2026 14:19:03 +0200
Subject: [PATCH] Fix type check of unsupported language codes in Stripe
 checkout session

---
 apps/api/src/app/subscription/subscription.service.ts     | 8 +++++---
 .../api/src/app/subscription/types/string-literal.type.ts | 7 -------
 2 files changed, 5 insertions(+), 10 deletions(-)
 delete mode 100644 apps/api/src/app/subscription/types/string-literal.type.ts

diff --git a/apps/api/src/app/subscription/subscription.service.ts b/apps/api/src/app/subscription/subscription.service.ts
index 143f89950b..17beba0077 100644
--- a/apps/api/src/app/subscription/subscription.service.ts
+++ b/apps/api/src/app/subscription/subscription.service.ts
@@ -23,8 +23,6 @@ import { addMilliseconds, isBefore } from 'date-fns';
 import ms, { StringValue } from 'ms';
 import Stripe from 'stripe';
 
-import { StringLiteral } from './types/string-literal.type';
-
 @Injectable()
 export class SubscriptionService {
   private readonly logger = new Logger(SubscriptionService.name);
@@ -270,7 +268,11 @@ export class SubscriptionService {
     const unsupportedLanguageCodes: Record<
       Exclude<
         (typeof SUPPORTED_LANGUAGE_CODES)[number],
-        StringLiteral<Stripe.Checkout.SessionCreateParams.Locale>
+        // Extract removes OtherString of Stripe, which matches every string
+        Extract<
+          Stripe.Checkout.SessionCreateParams.Locale,
+          (typeof SUPPORTED_LANGUAGE_CODES)[number]
+        >
       >,
       true
     > = {
diff --git a/apps/api/src/app/subscription/types/string-literal.type.ts b/apps/api/src/app/subscription/types/string-literal.type.ts
deleted file mode 100644
index 1f25cb81a4..0000000000
--- a/apps/api/src/app/subscription/types/string-literal.type.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-// Removes the open string type (e.g. OtherString of Stripe), which matches
-// every string, and keeps only the string literals
-export type StringLiteral<T> = T extends string
-  ? string extends T
-    ? never
-    : T
-  : never;