feat: Add response handling and error checking to POST /messages/:id/like

- Check if messageWithIdAsNumber exists after incrementing likes
- Notify all waiting clients via callBacksForNewMessages callbacks
- Send updated message with 200 status on success
- Return 404 error if message not found
- Enable real-time like updates via long polling
- Improve error handling for invalid message IDs

Author: Iswanna

chat-app/backend/server.js

@@ -78,6 +78,17 @@ app.post("/messages/:id/like", (req, res) => {
   );
 
   messageWithIdAsNumber.likes += 1;
+
+  if (messageWithIdAsNumber) {
+    while (callBacksForNewMessages.length > 0) {
+      const callback = callBacksForNewMessages.pop();
+
+      callback([messageWithIdAsNumber]);
+    }
+    res.status(200).send(messageWithIdAsNumber);
+  } else {
+    res.status(404).send("Message not found");
+  }
 });
 
 // Start the server