feat(#1): use stripe session to populate checkout success

src/routes/checkout/success/+page.ts

@@ -0,0 +1,27 @@
+import type { PageLoad } from './$types';
+import { redirect } from '@sveltejs/kit';
+import Stripe from 'stripe';
+
+export const load: PageLoad = async ({fetch}) => {
+  const response = await fetch('/api/checkout/status');
+	if (!response.ok) {
+		console.error('Failed to fetch checkout status');
+		return;
+	}
+
+	const responseJson = await response.json();
+	const checkoutSession: Stripe.Checkout.Session = responseJson.checkoutSession;
+	const lineItems: Stripe.LineItem[] = responseJson.lineItems.data;
+	const paymentStatus: Stripe.Checkout.Session.PaymentStatus = responseJson.paymentStatus;
+
+	if (paymentStatus == 'unpaid') {
+		throw redirect(303, '/checkout/cancelled');
+	}
+
+	return {
+		checkoutSession,
+		lineItems,
+		paymentStatus
+	};
+};
+