username sin caracteres extraños

src/pages/RegisterPage.vue

@@ -12,6 +12,7 @@
                 (val) =>
                   (val != null && val.length >= 3) || 'Mínimo 3 caracteres',
                 (val) => comprobarUsername || 'Ya existe en la BD',
+                (val) => /^[A-Z0-9]+$/i.test(val) || 'Sólo letras o números'
               ]" />
               <q-input square filled clearable v-model="nombre" type="text" label="nombre completo" :rules="[
                 (val) =>
@@ -93,6 +94,7 @@ const btnRegisterDisable = () => {
     username.value == null ||
     username.value.length < 3 ||
     !comprobarUsername.value ||
+    !/^[A-Z0-9]+$/i.test(username.value) ||
     nombre.value == null ||
     nombre.value.length < 3 ||
     email.value == null ||
@@ -117,14 +119,6 @@ const registrar = () => {
     'passwordConfirm': confirmpassword.value,
     'name': nombre.value
   }
-  /*   const data = {
-      "username": "test_username",
-      "email": "test@example.com",
-      "emailVisibility": true,
-      "password": "12345678",
-      "passwordConfirm": "12345678",
-      "name": "test"
-    }; */
   listaStore.register(data)
 }
 </script>