add error handling and graceful shutdown

[nikgraf]

No description provided.

[Copilot]

Pull Request Overview

This PR enhances server robustness by adding middleware for request timeouts, centralized error handling, and graceful shutdown logic.

• Introduces a 30s timeout middleware to send 408 responses on slow requests
• Adds global error and 404 handlers for consistent API responses
• Registers process-level handlers for unhandled rejections, uncaught exceptions, and OS signals to cleanly close HTTP and WebSocket servers

Comments suppressed due to low confidence (2)

apps/server/src/index.ts:71

• Add tests to verify the 30s timeout triggers correctly and returns a 408, and to simulate long-running routes to confirm the behavior.

// Request timeout middleware

apps/server/src/index.ts:74

• [nitpick] For consistency with other error responses, consider adding a message field alongside error, or align the JSON shape with your global error handler.

    res.status(408).json({ error: 'Request timeout' });

[Copilot]

In this handler, you close only the HTTP server. To fully shut down, also call webSocketServer.close() before exiting to avoid leaving socket connections open.

[Copilot]

Uncaught promise rejections can leave the process in an inconsistent state. Consider invoking the same shutdown logic as for uncaughtException or at least logging and exiting after a grace period.

Suggested change

	console.error('Unhandled Rejection at:', promise, 'reason:', reason);
	console.error('Unhandled Rejection at:', promise, 'reason:', reason);
	// Graceful shutdown
	server.close(() => {
	console.log('Server closed due to unhandled rejection');
	webSocketServer.close(() => {
	console.log('WebSocket server closed');
	process.exit(1);
	});
	});
	// Force close after 30 seconds
	setTimeout(() => {
	console.error('Could not close connections in time, forcefully shutting down');
	process.exit(1);
	}, 30000);

[Copilot]

After sending the timeout response, ensure no further handlers write to the response (e.g., by storing a flag or directly ending the response) to avoid double send errors.

Suggested change

	res.setTimeout(30000, () => {
	res.status(408).json({ error: 'Request timeout' });
	});
	let responseSent = false;
	res.setTimeout(30000, () => {
	if (!responseSent) {
	responseSent = true;
	res.status(408).json({ error: 'Request timeout' });
	}
	});
	res.on('finish', () => {
	responseSent = true;
	});