From f5ec9ee2a668930564499212cbc12b0f63fe00ee Mon Sep 17 00:00:00 2001
From: Tim Perry <pimterry@gmail.com>
Date: Mon, 9 Sep 2024 14:58:51 +0200
Subject: [PATCH] Actually check the theme extends field value

---
 src/model/ui/ui-store.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/model/ui/ui-store.ts b/src/model/ui/ui-store.ts
index b7d67faf..557c85cb 100644
--- a/src/model/ui/ui-store.ts
+++ b/src/model/ui/ui-store.ts
@@ -157,7 +157,12 @@ export class UiStore {
         if (!themeData) throw new Error("Could not parse theme JSON");
 
         if (!themeData.name) throw new Error('Theme must contain a `name` field');
-        if (!themeData.extends) throw new Error('Theme must contain an `extends` field with a built-in theme name (dark/light/high-contrast)');
+        if (
+            !themeData.extends ||
+            Themes[themeData.extends as ThemeName] === undefined
+        ) {
+            throw new Error('Theme must contain an `extends` field with a built-in theme name (dark/light/high-contrast)');
+        }
 
         const baseTheme = Themes[themeData.extends];
         return {