feat(#76): Ensure pagination is only possible for valid pages

src/lib/utils/supabase/admin.ts

@@ -625,6 +625,8 @@ const getUserTransactions = async (
 
 		const charges = await stripeClient.charges.list(params);
 
+		const hasNextPage = charges.has_more;
+
 		// Step 3: Format transaction data
 		const transactions = charges.data.map((charge) => ({
 			id: charge.id,
@@ -640,7 +642,7 @@ const getUserTransactions = async (
 			receipt_url: charge.receipt_url
 		}));
 
-		return transactions;
+		return { transactions, hasNextPage };
 	} catch (error) {
 		console.error('An error occurred while retrieving transactions:', error);
 		throw new Error('Could not retrieve transactions');

src/routes/account/+page.server.ts

@@ -5,6 +5,8 @@ import { getUserSubscriptions, getUserTransactions } from '$lib/utils/supabase/a
 import { requestAccountDeletion } from '$lib/utils/supabase/admin';
 
 const transactionsPerPage = 5;
+let firstTransactionId: string;
+let hasMoreThanOnePage = false;
 
 export const load: PageServerLoad = async ({ locals: { supabase, safeGetSession } }) => {
 	const { session } = await safeGetSession();
@@ -21,9 +23,19 @@ export const load: PageServerLoad = async ({ locals: { supabase, safeGetSession
 
 	const subscriptions = await getUserSubscriptions(session.user.id);
 
-	const transactions = await getUserTransactions(session.user.id, transactionsPerPage);
+	const transactionsData = await getUserTransactions(session.user.id, transactionsPerPage);
 
-	return { session, user, subscriptions, transactions, pageSize: transactionsPerPage };
+	const transactions = transactionsData.transactions;
+	firstTransactionId = transactions[0]?.id;
+	hasMoreThanOnePage = transactionsData.hasNextPage;
+
+	return {
+		session,
+		user,
+		subscriptions,
+		transactions,
+		pageSize: transactionsPerPage
+	};
 };
 
 export const actions: Actions = {
@@ -84,25 +96,34 @@ export const actions: Actions = {
 	paginate: async ({ request, locals: { safeGetSession } }) => {
 		const formData = await request.formData();
 		const pageSize = transactionsPerPage;
-		const startingAfter = formData.get('startingAfter')?.toString() || undefined;
-		const endingBefore = formData.get('endingBefore')?.toString() || undefined;
+
+		let startingAfter = formData.get('startingAfter')?.toString() || undefined;
+		if (startingAfter === 'undefined') {
+			startingAfter = undefined;
+		}
+		let endingBefore = formData.get('endingBefore')?.toString() || undefined;
+		if (endingBefore === 'undefined') {
+			endingBefore = undefined;
+		}
 
 		const { session } = await safeGetSession();
 		if (!session) return fail(401, { error: 'Not authenticated' });
 
 		try {
-			const transactions = await getUserTransactions(
+			const { transactions, hasNextPage } = await getUserTransactions(
 				session.user.id,
 				pageSize,
 				startingAfter,
 				endingBefore
 			);
 
-			const serializableTransactions = transactions.map((transaction) => ({ ...transaction }));
+			const isFirstPage = transactions[0].id === firstTransactionId;
 
-			const stringifiedTransactions: string = JSON.stringify(serializableTransactions);
-
-			return { stringifiedTransactions };
+			return {
+				transactions: JSON.stringify(transactions),
+				hasNextPage: hasNextPage || (isFirstPage && hasMoreThanOnePage),
+				isFirstPage
+			};
 		} catch (error) {
 			logger.error('Failed to fetch transactions', { userId: session.user.id, error });
 			return fail(500, { error: 'Failed to load transactions' });

src/routes/account/+page.svelte

@@ -1,5 +1,4 @@
 <script lang="ts">
-	import { onMount } from 'svelte';
 	import { enhance } from '$app/forms';
 	import type { SubmitFunction } from '@sveltejs/kit';
 
@@ -41,39 +40,21 @@
 		};
 	};
 
-	// Track pagination IDs for Stripe-based pagination
 	let startingAfter: string | undefined = undefined;
 	let endingBefore: string | undefined = undefined;
+	let hasNextPage = true;
+	let hasPreviousPage = false;
 
-	// Function to trigger pagination
-	async function goToPage(direction: 'next' | 'previous') {
+	const handlePaginationSubmit: SubmitFunction = () => {
 		loading = true;
 
-		// Set up formData with appropriate IDs for pagination
-		const formData = new FormData();
-		if (direction === 'next' && transactions.length) {
-			startingAfter = transactions[transactions.length - 1].id;
-			formData.append('startingAfter', startingAfter);
-			endingBefore = undefined; // Reset `endingBefore` for forward navigation
-		} else if (direction === 'previous' && transactions.length) {
-			endingBefore = transactions[0].id;
-			formData.append('endingBefore', endingBefore);
-			startingAfter = undefined; // Reset `startingAfter` for backward navigation
-		}
-
-		// Fetch paginated transactions
-		const response = await fetch('/account?/paginate', {
-			method: 'POST',
-			body: formData
-		});
-
-		const result = await response.json();
-
-		// TODO - work out why the data comes back in such a weird format here
-		transactions = JSON.parse(JSON.parse(result.data)[1]);
-
-		loading = false;
-	}
+		return async ({ result }) => {
+			transactions = JSON.parse(result.data.transactions);
+			hasNextPage = result.data.hasNextPage;
+			hasPreviousPage = !result.data.isFirstPage;
+			loading = false;
+		};
+	};
 </script>
 
 <div
@@ -187,24 +168,45 @@
 					<p class="text-gray-600">No transactions found.</p>
 				{/if}
 
-				<!-- Pagination Controls -->
-				<div class="flex justify-center items-center space-x-2 mt-4">
-					<button
-						class="btn btn-outline"
-						disabled={!transactions.length || loading}
-						on:click={() => goToPage('previous')}
-					>
-						Previous
-					</button>
+				<!-- Pagination Form -->
+				<form method="post" action="?/paginate" use:enhance={handlePaginationSubmit}>
+					<div class="flex justify-center items-center space-x-2 mt-4">
+						<input type="hidden" name="startingAfter" value={startingAfter} />
+						<input type="hidden" name="endingBefore" value={endingBefore} />
 
-					<button
-						class="btn btn-outline"
-						disabled={!transactions.length || loading}
-						on:click={() => goToPage('next')}
-					>
-						Next
-					</button>
-				</div>
+						<button
+							type="submit"
+							name="direction"
+							value="previous"
+							class="btn btn-outline"
+							disabled={!hasPreviousPage || loading}
+							on:click={() => {
+								if (transactions.length) {
+									endingBefore = transactions[0].id;
+									startingAfter = undefined;
+								}
+							}}
+						>
+							Previous
+						</button>
+
+						<button
+							type="submit"
+							name="direction"
+							value="next"
+							class="btn btn-outline"
+							disabled={!hasNextPage || loading}
+							on:click={() => {
+								if (transactions.length) {
+									startingAfter = transactions[transactions.length - 1].id;
+									endingBefore = undefined;
+								}
+							}}
+						>
+							Next
+						</button>
+					</div>
+				</form>
 			</section>
 		</div>