refactor(frontend): Algemene linting fouten

frontend/src/services/auth/auth-config-loader.ts

@@ -1,10 +1,11 @@
 import apiClient from "@/services/api-client.ts";
 import type { FrontendAuthConfig } from "@/services/auth/auth.d.ts";
+import type {UserManagerSettings} from "oidc-client-ts";
 
 /**
  * Fetch the authentication configuration from the backend.
  */
-export async function loadAuthConfig() {
+export async function loadAuthConfig(): Promise<Record<string, UserManagerSettings>> {
     const authConfig = (await apiClient.get<FrontendAuthConfig>("auth/config")).data;
     return {
         student: {

frontend/src/services/auth/auth-service.ts

@@ -49,7 +49,7 @@ const isLoggedIn = computed(() => authState.user !== null);
 /**
  * Redirect the user to the login page where he/she can choose whether to log in as a student or teacher.
  */
-async function initiateLogin() {
+async function initiateLogin(): Promise<void> {
     await router.push(loginRoute);
 }
 
@@ -77,12 +77,12 @@ async function handleLoginCallback(): Promise<void> {
 /**
  * Refresh an expired authorization token.
  */
-async function renewToken() {
+async function renewToken(): Promise<User | null> {
     const activeRole = authStorage.getActiveRole();
     if (!activeRole) {
         console.log("Can't renew the token: Not logged in!");
         await initiateLogin();
-        return;
+        return null;
     }
     try {
         return await (await getUserManagers())[activeRole].signinSilent();
@@ -91,6 +91,7 @@ async function renewToken() {
         console.log(error);
         await initiateLogin();
     }
+    return null;
 }
 
 /**
@@ -113,7 +114,7 @@ apiClient.interceptors.request.use(
         }
         return reqConfig;
     },
-    (error) => Promise.reject(error),
+    async (error) => Promise.reject(error),
 );
 
 // Registering interceptor to refresh the token when a request failed because it was expired.
@@ -121,7 +122,7 @@ apiClient.interceptors.response.use(
     (response) => response,
     async (error: AxiosError<{ message?: string }>) => {
         if (error.response?.status === 401) {
-            if (error.response!.data.message === "token_expired") {
+            if (error.response.data.message === "token_expired") {
                 console.log("Access token expired, trying to refresh...");
                 await renewToken();
                 return apiClient(error.config!); // Retry the request

frontend/src/services/auth/auth-storage.ts

@@ -12,7 +12,7 @@ export default {
      * Set the role the user is currently logged in as from the local persistent storage.
      * This should happen when the user logs in with another account.
      */
-    setActiveRole(role: Role) {
+    setActiveRole(role: Role): void {
         localStorage.setItem("activeRole", role);
     },
 
@@ -20,7 +20,7 @@ export default {
      * Remove the saved current role from the local persistent storage.
      * This should happen when the user is logged out.
      */
-    deleteActiveRole() {
+    deleteActiveRole(): void {
         localStorage.removeItem("activeRole");
     },
 };

frontend/src/services/auth/auth.d.ts

@@ -1,22 +1,22 @@
 import { type User, UserManager } from "oidc-client-ts";
 
-export type AuthState = {
+export interface AuthState {
     user: User | null;
     accessToken: string | null;
     activeRole: Role | null;
-};
+}
 
-export type FrontendAuthConfig = {
+export interface FrontendAuthConfig {
     student: FrontendIdpConfig;
     teacher: FrontendIdpConfig;
-};
+}
 
-export type FrontendIdpConfig = {
+export interface FrontendIdpConfig {
     authority: string;
     clientId: string;
     scope: string;
     responseType: string;
-};
+}
 
 export type Role = "student" | "teacher";
-export type UserManagersForRoles = { student: UserManager; teacher: UserManager };
+export interface UserManagersForRoles { student: UserManager; teacher: UserManager }