Support basePath in all queries.

pages/api/auth/logout.js

@@ -1,6 +1,6 @@
 import { serialize } from 'cookie';
 import { AUTH_COOKIE_NAME } from 'lib/constants';
-import { redirect } from 'lib/response';
+import { ok } from 'lib/response';
 
 export default async (req, res) => {
   const cookie = serialize(AUTH_COOKIE_NAME, '', {
@@ -11,5 +11,5 @@ export default async (req, res) => {
 
   res.setHeader('Set-Cookie', [cookie]);
 
-  return redirect(res, '/login');
+  return ok(res);
 };

pages/logout.js

@@ -1,8 +1,12 @@
 import { useEffect } from 'react';
+import { useRouter } from 'next/router';
 
 export default function LogoutPage() {
+  const router = useRouter();
+  const { basePath } = router;
+
   useEffect(() => {
-    fetch('/api/auth/logout').then(() => (window.location.href = '/login'));
+    fetch(`${basePath}/api/auth/logout`).then(() => router.push('/login'));
   }, []);
 
   return null;