fix: add ping to SSE routes to keep connection alive

Author: FreekBes

src/routes/sse.ts

@@ -79,3 +79,16 @@ export const setupServerSideEventsRoutes = function(app: Express, prisma: Prisma
 		}
 	});
 };
+
+// Ping all clients every 15 seconds to keep the connection alive
+setInterval(() => {
+	for (const stream in sseClients) {
+		sseClients[stream as SSEStream].forEach(client => {
+			try {
+				triggerSSE(stream as SSEStream, 'ping', { timestamp: Date.now() });
+			} catch (err) {
+				console.error('Error writing ping to SSE client:', err);
+			}
+		});
+	}
+}, 15000);

static/js/live-scores.js

@@ -7,6 +7,10 @@ scoresEventSource.onopen = function() {
 	console.log('Scores SSE connection opened.');
 };
 
+scoresEventSource.addEventListener('ping', function(event) {
+	console.log('Received ping from scores SSE.');
+});
+
 scoresEventSource.addEventListener('new_score', function(event) {
 	const data = JSON.parse(event.data);
 	console.log('New score:', data);