✨ Improved authentication by checking the jwt in SvelteKit

frontend/src/hooks.server.ts

@@ -5,30 +5,39 @@
  */
 
 import type { Handle } from '@sveltejs/kit';
+import jws from 'jws';
 
 /** @type {import('@sveltejs/kit').Handle} */
 export const handle: Handle = async ({ event, resolve }) => {
-	const res = await fetch(`${process.env.API_URL}/api/v1/users/check`, {
-		method: 'GET',
-		headers: {
-			'Content-Type': 'application/json',
-			Cookie: event.request.headers.get('cookie') || ''
-		}
-	});
-	if (res.ok) {
-		event.locals.email = await res.text();
-		const resp = await resolve(event);
-		try {
-			resp.headers.set('Set-Cookie', res.headers.get('set-cookie'));
-		} catch {
-			console.log('Cannot mutate immutable header');
-		}
-
-		return resp;
-	} else {
+	const access_token = event.cookies.get('access_token');
+	if (!access_token) {
 		event.locals.email = null;
 		return resolve(event);
 	}
+	const jwt = jws.decode(access_token.replace('Bearer ', ''));
+	// if token expires, do a request to get a new one and set the response-cookies on the response
+	if (Date.now() >= jwt.payload.exp * 1000) {
+		const res = await fetch(`${process.env.API_URL}/api/v1/users/check`, {
+			method: 'GET',
+			headers: {
+				'Content-Type': 'application/json',
+				Cookie: event.request.headers.get('cookie') || ''
+			}
+		});
+		if (res.ok) {
+			event.locals.email = await res.text();
+			const resp = await resolve(event);
+			console.log(res.headers.get('set-cookie'));
+			try {
+				resp.headers.set('Set-Cookie', res.headers.get('set-cookie'));
+			} catch {
+				/* empty */
+			}
+			return resp;
+		}
+	}
+	event.locals.email = jwt.payload.sub;
+	return resolve(event);
 };
 
 /*export const getSession: GetSession = async (event) => {