fix(inputComponent): fix TypeScript error by adding non-null assertion to className variable

fix(authContext): fix TypeScript error by setting initial value of userData to null
fix(tsconfig.json): enable strict mode in TypeScript compiler for better type checking and error detection

src/frontend/src/components/inputComponent/index.tsx

@@ -39,7 +39,7 @@ export default function InputComponent({
               editNode ? " input-edit-node " : "",
               password && editNode ? "pr-8" : "",
               password && !editNode ? "pr-10" : "",
-              className
+              className!
             )}
             placeholder={password && editNode ? "Key" : placeholder}
             onChange={(e) => {
@@ -59,7 +59,7 @@ export default function InputComponent({
             editNode ? " input-edit-node " : "",
             password && editNode ? "pr-8" : "",
             password && !editNode ? "pr-10" : "",
-            className
+            className!
           )}
           placeholder={password && editNode ? "Key" : placeholder}
           onChange={(e) => {

src/frontend/src/contexts/authContext.tsx

@@ -15,7 +15,7 @@ const AuthContext = createContext<AuthContextType>(initialValue);
 
 export function AuthProvider({ children }): React.ReactElement {
   const [accessToken, setAccessToken] = useState<string | null>(null);
-  const [userData, setUserData] = useState<userData>(null);
+  const [userData, setUserData] = useState<userData | null>(null);
 
   useEffect(() => {
     const storedAccessToken = localStorage.getItem("access_token");

src/frontend/tsconfig.json

@@ -6,7 +6,7 @@
     "skipLibCheck": true,
     "esModuleInterop": true,
     "allowSyntheticDefaultImports": true,
-    "strict": false,
+    "strict": true,
     "forceConsistentCasingInFileNames": true,
     "noFallthroughCasesInSwitch": true,
     "module": "esnext",