check if new account data is non-empty

src/routes/(angemeldet)/user-management/+page.svelte

@@ -8,7 +8,7 @@
 
     let userName = $state('')
     let userPassword = $state('')
-    let userList = $state([])
+    let userList: { userId: string; userName: string }[] = $state([])
     let addUserError = $state(false);
     let addUserSuccess = $state(false);
     const currentUser: string = data.user.id;
@@ -65,7 +65,7 @@
         }, 5000);
     }
 
-    async function deleteUser(userId: number) {
+    async function deleteUser(userId: string) {
         const URL = `/api/users/${userId}`;
 
         const response = await fetch(URL, {

src/routes/api/users/+server.ts

@@ -19,6 +19,11 @@ export async function POST({ request, locals }) {
 	const data = await request.json();
 	const userName = data.userName;
 	const userPassword = data.userPassword;
+
+	if (!userName || !userPassword) {
+		return json({ error: 'Missing input' }, { status: 400 });
+	}
+
 	const rowCount = addUser(userName, userPassword);
 
 	return new Response(null, { status: rowCount == 1 ? 200 : 400 });