fix(storage): don't crash when the browser's storage is unusable

src/core/localStorage.ts

@@ -59,9 +59,24 @@ export const saveState = (state: RootState) => {
 };
 
 export const clearSessionStorage = () => {
-  globalThis.sessionStorage.clear();
+  try {
+    globalThis.sessionStorage.clear();
+  } catch (_) { // Ignore storage errors, nothing was persisted.
+  }
 };
 
 export const clearApiSession = () => {
-  globalThis.localStorage.removeItem('apiSession');
+  try {
+    globalThis.localStorage.removeItem('apiSession');
+  } catch (_) { // Ignore storage errors, nothing was persisted.
+  }
+};
+
+// Browsers can throw on any storage access (e.g. Firefox's NS_ERROR_FAILURE when site storage is unusable).
+export const getStoredTheme = () => {
+  try {
+    return globalThis.localStorage.getItem('theme');
+  } catch (_) {
+    return null;
+  }
 };

src/core/router/index.tsx

@@ -1,11 +1,11 @@
-/* global globalThis */
 import { useEffect, useRef, useState } from 'react';
 import { Navigate, Route, createBrowserRouter, createRoutesFromElements } from 'react-router';
 import { RouterProvider } from 'react-router/dom';
 import * as Sentry from '@sentry/react';
 
 import ErrorBoundary from '@/components/ErrorBoundary';
 import ReleaseManagementSeriesDetail from '@/components/Utilities/ReleaseManagement/ReleaseManagementSeriesDetail';
+import { getStoredTheme } from '@/core/localStorage';
 import { useServerStatusQuery } from '@/core/react-query/init/queries';
 import { useSettingsQuery } from '@/core/react-query/settings/queries';
 import { useSelector } from '@/core/store';
@@ -164,9 +164,7 @@ const Router = () => {
   const [bodyVisible, setBodyVisible] = useState(false);
 
   useEffect(() => {
-    document.body.className = `${
-      apikey === '' ? globalThis.localStorage.getItem('theme') : (webuiPreviewTheme || theme)
-    } theme-shoko-gray`;
+    document.body.className = `${apikey === '' ? getStoredTheme() : (webuiPreviewTheme || theme)} theme-shoko-gray`;
     const timeoutId = setTimeout(() => {
       if (bodyRef.current) {
         bodyRef.current.style.visibility = 'initial';