Tried Validation - didnt succeed

validation.js

@@ -1,5 +1,18 @@
+const Restaurant = require("./models/restaurant");
+const Dish = require("./models/dish");
+const User = require("./models/users");
+
 function validateRestaurant(id) {
-  return true;
+  /*Restaurant.findById(id, (err, data) => {
+    if (err) return err;
+    else return data;
+  });*/
+  return id;
+}
+
+function validateUser(id) {
+  return id;
 }
 
 exports.validateRestaurant = validateRestaurant;
+exports.validateUser = validateUser;