refactor: change backend to typescript and update types and variables accordingly

backend/services/tokenService.ts

@@ -1,25 +1,36 @@
-import {jwtVerify, SignJWT} from "jose";
+import type {NextFunction, Request, Response} from "express";
+import {type JWTPayload, jwtVerify, SignJWT} from "jose";
 import env from "dotenv";
 
 env.config();
 const secret = new TextEncoder().encode(process.env.SECRET_KEY);
 
-export async function generateToken(payload) {
-  return await new SignJWT(payload)
-      .setProtectedHeader({alg: "HS256"})
-      .setIssuedAt()
-      .setExpirationTime("24h") // Token valid for 24 hours
-      .sign(secret);
+export type AuthTokenPayload = JWTPayload & {
+    username: string;
+};
+
+declare module "express-serve-static-core" {
+    interface Request {
+        user?: AuthTokenPayload;
+    }
 }
 
-export async function authenticate(req, res, next) {
-  const authHeader = req.headers["authorization"];
-  const token = authHeader && authHeader.split(" ")[1]; // Bearer <token>
-
-  if (token == null) return res.sendStatus(401); // No token present
-
-  const { payload } = await jwtVerify(token, secret);
-  req.user = payload;
-
-  next();
+export async function generateToken(payload: AuthTokenPayload) {
+    return await new SignJWT(payload)
+        .setProtectedHeader({alg: "HS256"})
+        .setIssuedAt()
+        .setExpirationTime("24h")
+        .sign(secret);
 }
+
+export async function authenticate(req: Request, res: Response, next: NextFunction) {
+    const authHeader = req.headers["authorization"];
+    const token = authHeader && authHeader.split(" ")[1];
+
+    if (token == null) return res.sendStatus(401);
+
+    const {payload} = await jwtVerify<AuthTokenPayload>(token, secret);
+    req.user = payload;
+
+    next();
+}