Nomey: Dev Test Solution

[ahmed563]

This PR implements a reusable Server-Sent Events (SSE) layer for real-time, server-to-client communication across the application. The solution provides a clean abstraction for managing client connections, broadcasting events, and sending targeted messages.

Key Changes:

• SSEManager Service: Added a centralized SSEManager class to manage SSE clients. Supports adding/removing clients by userId, sending targeted events to specific users, and broadcasting events to all connected clients. Handles client connection cleanup on write failure.
• API Endpoints:
  • GET /api/sse: Establishes an SSE connection for the given userId, sends an initial connected event, includes a heartbeat (ping every 15s), and cleans up on disconnect.
  • POST /api/sse: Allows sending a specific event and payload to a given userId.
• Connection Stability Improvements: Added retry: 10000 for reconnection attempts, implemented ping events to keep connections alive, and gracefully removed disconnected clients to prevent memory leaks.

Benefits

• Decouples SSE logic from API routes, allowing easy reuse across the app.
• Enables both targeted user messaging and global broadcasts.
• Improves scalability by managing connections efficiently.
• Maintains connection reliability with heartbeats and retry intervals.

Testing

• Verified that clients receive initial connected event, regular ping events, and targeted events via POST /api/sse.
• Tested disconnection and reconnection scenarios.
• Confirmed no memory leaks after client disconnections.

Loom of changes in action:
https://www.loom.com/share/3e51861dffe64da3958ac4759e347b38