feat: add, delete student route met user logic + .js in files

backend/src/interfaces/user.ts

@@ -0,0 +1,30 @@
+import { User } from "../entities/users/user.entity.js";
+
+export interface UserDTO {
+    id?: string,
+    username: string;
+    firstName: string;
+    lastName: string;
+    endpoints?: {
+        self: string;
+        classes: string;
+        questions: string;
+        invitations: string;
+    };
+}
+
+export function mapToUserDTO(user: User): UserDTO {
+    return {
+        id: user.username,
+        username: user.username,
+        firstName: user.firstName,
+        lastName: user.lastName,
+    };
+}
+
+export function mapToUser<T extends User>(userData: UserDTO, userInstance: T): T {
+    userInstance.username = userData.username;
+    userInstance.firstName = userData.firstName;
+    userInstance.lastName = userData.lastName;
+    return userInstance;
+}