fix(lint): resolve errcheck violations for deferred resource closures

AVC/BFT/bft/buddy_service.go

@@ -149,7 +149,11 @@ func (s *BuddyService) runBFTConsensus(ctx context.Context, req *pb.BFTRequest)
 		s.reportFailure(req, fmt.Sprintf("failed to create BFT adapter: %v", err))
 		return
 	}
-	defer adapter.Close()
+	defer func() {
+		if err := adapter.Close(); err != nil {
+			log.Printf("⚠️ [%s] Failed to close BFT adapter: %v", s.buddyID, err)
+		}
+	}()
 
 	log.Printf("✅ [%s] BFT adapter initialized on channel: %s", s.buddyID, req.GossipsubTopic)
 
@@ -211,7 +215,11 @@ func (s *BuddyService) reportResult(req *pb.BFTRequest, result *Result) {
 		log.Printf("❌ [%s] Failed to connect to sequencer: %v", s.buddyID, err)
 		return
 	}
-	defer conn.Close()
+	defer func() {
+		if closeErr := conn.Close(); closeErr != nil {
+			log.Printf("⚠️ [%s] Failed to close sequencer connection: %v", s.buddyID, closeErr)
+		}
+	}()
 
 	client := pb.NewBFTServiceClient(conn)
 
@@ -255,7 +263,11 @@ func (s *BuddyService) reportFailure(req *pb.BFTRequest, reason string) {
 		log.Printf("❌ [%s] Failed to connect to sequencer: %v", s.buddyID, err)
 		return
 	}
-	defer conn.Close()
+	defer func() {
+		if closeErr := conn.Close(); closeErr != nil {
+			log.Printf("⚠️ [%s] Failed to close sequencer connection: %v", s.buddyID, closeErr)
+		}
+	}()
 
 	client := pb.NewBFTServiceClient(conn)
 	pbResult := &pb.BFTResult{

AVC/BFT/bft/sequencer_client.go

@@ -165,7 +165,11 @@ func (s *SequencerBFTClient) sendBFTRequest(
 			Message:  fmt.Sprintf("connection failed: %v", err),
 		}
 	}
-	defer conn.Close()
+	defer func() {
+		if err := conn.Close(); err != nil {
+			log.Printf("❌ [Sequencer] Failed to close connection to %s: %v", buddy.ID, err)
+		}
+	}()
 
 	client := pb.NewBFTServiceClient(conn)
 

AVC/BFT/network/libp2p_setup.go

@@ -31,7 +31,9 @@ func SetupLibp2pHost(ctx context.Context, port int) (host.Host, *pubsub.PubSub,
 	// Create GossipSub
 	ps, err := pubsub.NewGossipSub(ctx, h)
 	if err != nil {
-		h.Close()
+		if closeErr := h.Close(); closeErr != nil {
+			fmt.Printf("❌ Failed to close libp2p host: %v\n", closeErr)
+		}
 		return nil, nil, fmt.Errorf("failed to create gossipsub: %w", err)
 	}
 

AVC/BuddyNodes/MessagePassing/BuddyNodeStream.go

@@ -53,7 +53,11 @@ func NewStructBuddyNode(buddy *AVCStruct.BuddyNode) *StructBuddyNode {
 
 // HandleBuddyNodesMessageStream handles incoming messages on the buddy nodes protocol
 func (StructBuddyNode *StructBuddyNode) HandleBuddyNodesMessageStream(host host.Host, s network.Stream) {
-	defer s.Close()
+	defer func() {
+		if err := s.Close(); err != nil {
+			logger().NamedLogger.Error(context.Background(), "Failed to close buddy nodes stream", err)
+		}
+	}()
 
 	// Create context for this stream handler
 	spanCtx := StructBuddyNode.logger_ctx

AVC/BuddyNodes/MessagePassing/ListenerHandler.go

@@ -75,7 +75,11 @@ func (lh *ListenerHandler) HandleSubmitMessageStream(logger_ctx context.Context,
 		attribute.String("remote_peer_id", remotePeer.String()),
 	)
 	// Ensure stream is closed to prevent resource leaks
-	defer s.Close()
+	defer func() {
+		if err := s.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+		}
+	}()
 
 	logger().NamedLogger.Info(spanCtx, "ListenerHandler.HandleSubmitMessageStream CALLED",
 		ion.String("remote_peer_id", remotePeer.String()),
@@ -173,15 +177,23 @@ func (lh *ListenerHandler) HandleSubmitMessageStream(logger_ctx context.Context,
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.HandleSubmitMessageStream"))
 		lh.handleBFTRequest(spanCtx, s, message)
-		defer s.Close()
+		defer func() {
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+			}
+		}()
 	case config.Type_SubmitVote:
 		logger().NamedLogger.Info(spanCtx, "Handling Type_SubmitVote",
 			ion.String("created_at", time.Now().UTC().Format(time.RFC3339)),
 			ion.String("log_file", LOG_FILE),
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.HandleSubmitMessageStream"))
 		lh.handleSubmitVote(spanCtx, s, message)
-		defer s.Close()
+		defer func() {
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+			}
+		}()
 	case config.Type_AskForSubscription:
 		logger().NamedLogger.Info(spanCtx, "Handling Type_AskForSubscription",
 			ion.String("created_at", time.Now().UTC().Format(time.RFC3339)),
@@ -196,15 +208,23 @@ func (lh *ListenerHandler) HandleSubmitMessageStream(logger_ctx context.Context,
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.HandleSubmitMessageStream"))
 		lh.handleSubscriptionResponse(spanCtx, s, message)
-		defer s.Close()
+		defer func() {
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+			}
+		}()
 	case config.Type_VoteResult:
 		logger().NamedLogger.Info(spanCtx, "Handling Type_VoteResult",
 			ion.String("created_at", time.Now().UTC().Format(time.RFC3339)),
 			ion.String("log_file", LOG_FILE),
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.HandleSubmitMessageStream"))
 		lh.handleVoteResultRequest(spanCtx, s, message)
-		defer s.Close()
+		defer func() {
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+			}
+		}()
 	default:
 		span.SetAttributes(attribute.String("status", "unknown_message_type"))
 		logger().NamedLogger.Error(spanCtx, "Unknown message type",
@@ -215,7 +235,11 @@ func (lh *ListenerHandler) HandleSubmitMessageStream(logger_ctx context.Context,
 			ion.String("log_file", LOG_FILE),
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.HandleSubmitMessageStream"))
-		defer s.Close()
+		defer func() {
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+			}
+		}()
 	}
 
 	duration := time.Since(startTime).Seconds()
@@ -608,7 +632,11 @@ func (lh *ListenerHandler) runBFTConsensusFlow(logger_ctx context.Context, conte
 		lh.sendBFTResultToSequencer(consensusSpanCtx, bftCtx.Round, bftCtx.BlockHash, myBuddyID, false, "REJECT", fmt.Sprintf("Failed to create adapter: %v", err))
 		return
 	}
-	defer adapter.Close()
+	defer func() {
+		if err := adapter.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close BFT adapter", err)
+		}
+	}()
 
 	logger().NamedLogger.Info(consensusSpanCtx, "BFT adapter created successfully",
 		ion.String("context_key", contextKey),
@@ -865,7 +893,11 @@ func (lh *ListenerHandler) sendBFTResultToSequencer(
 			ion.String("function", "MessagePassing.sendBFTResultToSequencer"))
 		return
 	}
-	defer stream.Close()
+	defer func() {
+		if err := stream.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close stream to Sequencer", err)
+		}
+	}()
 
 	// Send message
 	messageBytes, err := json.Marshal(message)
@@ -1400,7 +1432,9 @@ func (lh *ListenerHandler) sendSubscriptionResponse(logger_ctx context.Context,
 			ion.String("log_file", LOG_FILE),
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.sendSubscriptionResponse"))
-		s.Close()
+		if err := s.Close(); err != nil {
+			logger().NamedLogger.Warn(logger_ctx, "Failed to close stream", ion.String("error", err.Error()))
+		}
 		return
 	}
 
@@ -1419,7 +1453,9 @@ func (lh *ListenerHandler) sendSubscriptionResponse(logger_ctx context.Context,
 			ion.String("log_file", LOG_FILE),
 			ion.String("topic", TOPIC),
 			ion.String("function", "MessagePassing.sendSubscriptionResponse"))
-		s.Close()
+		if err := s.Close(); err != nil {
+			logger().NamedLogger.Warn(logger_ctx, "Failed to close stream", ion.String("error", err.Error()))
+		}
 		return
 	}
 
@@ -1432,7 +1468,9 @@ func (lh *ListenerHandler) sendSubscriptionResponse(logger_ctx context.Context,
 				ion.String("error", err.Error()),
 				ion.String("remote_peer_id", remotePeer.String()),
 				ion.String("function", "MessagePassing.sendSubscriptionResponse"))
-			s.Close()
+			if err := s.Close(); err != nil {
+				logger().NamedLogger.Warn(logger_ctx, "Failed to close stream", ion.String("error", err.Error()))
+			}
 			return
 		}
 	}
@@ -1442,7 +1480,9 @@ func (lh *ListenerHandler) sendSubscriptionResponse(logger_ctx context.Context,
 	// This is critical for preventing stream reset errors after prolonged runtime
 	time.Sleep(200 * time.Millisecond)
 
-	s.Close()
+	if err := s.Close(); err != nil {
+		logger().NamedLogger.Warn(logger_ctx, "Failed to close stream", ion.String("error", err.Error()))
+	}
 
 	duration := time.Since(startTime).Seconds()
 	sendSpan.SetAttributes(attribute.Float64("duration", duration), attribute.Int("bytes_written", bytesWritten), attribute.String("status", "success"))
@@ -1709,7 +1749,11 @@ func (lh *ListenerHandler) TriggerForBFTFromSequencer(s network.Stream, message
 			return
 		}
 	}
-	defer s.Close()
+	defer func() {
+		if err := s.Close(); err != nil {
+			fmt.Printf("Failed to close stream: %v\n", err)
+		}
+	}()
 
 	fmt.Println("📩 Received BFT trigger from Sequencer:", message)
 
@@ -1833,7 +1877,9 @@ func (lh *ListenerHandler) TriggerForBFTFromSequencer(s network.Stream, message
 				return nil
 			}
 			defer func() {
-				stream.Close()
+				if err := stream.Close(); err != nil {
+					fmt.Printf("Failed to close stream to %s: %v\n", buddyID, err)
+				}
 				fmt.Printf("🔌 Closed stream to %s\n", buddyID)
 			}()
 

AVC/BuddyNodes/MessagePassing/MessageListener.go

@@ -40,7 +40,11 @@ func (StructListenerNode *StructListener) HandleSubmitMessageStream(logger_ctx c
 	remotePeer := s.Conn().RemotePeer()
 	span.SetAttributes(attribute.String("remote_peer_id", remotePeer.String()))
 	// Ensure stream is closed to prevent resource leaks
-	defer s.Close()
+	defer func() {
+		if err := s.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close message stream", err)
+		}
+	}()
 
 	logger().NamedLogger.Info(spanCtx, "StructListener.HandleSubmitMessageStream called",
 		ion.String("remote_peer_id", remotePeer.String()),
@@ -471,7 +475,11 @@ func (StructListenerNode *StructListener) SendMessageToPeer(logger_ctx context.C
 	}
 	// CRITICAL FIX: Ensure stream is always closed to prevent file descriptor leaks
 	// particularly when read timeouts occur (lines 503-517)
-	defer stream.Close()
+	defer func() {
+		if err := stream.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream", err)
+		}
+	}()
 
 	sendSpan.SetAttributes(attribute.String("connection_method", "direct"))
 
@@ -681,7 +689,11 @@ func (StructListenerNode *StructListener) sendViaSeedNode(logger_ctx context.Con
 		seedSpan.SetAttributes(attribute.Float64("duration", duration))
 		return fmt.Errorf("failed to create stream to %s: %v", peerID, err)
 	}
-	defer stream.Close()
+	defer func() {
+		if err := stream.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close SubmitMessageStream via seed node", err)
+		}
+	}()
 
 	// Send the message
 	_, err = stream.Write([]byte(message + string(rune(config.Delimiter))))
@@ -790,7 +802,11 @@ func (StructListenerNode *StructListener) getPeerInfoFromSeedNode(logger_ctx con
 		peerInfoSpan.SetAttributes(attribute.Float64("duration", duration))
 		return nil, fmt.Errorf("failed to create seed node client: %v", err)
 	}
-	defer client.Close()
+	defer func() {
+		if err := client.Close(); err != nil {
+			logger().NamedLogger.Error(logger_ctx, "Failed to close seed node client", err)
+		}
+	}()
 
 	// Get peer record from seed node
 	peerRecord, err := client.GetPeer(peerID.String())

AVC/BuddyNodes/MessagePassing/Streamcache_Builder.go

@@ -154,7 +154,9 @@ func (sc *StructStreamCache) addEntry(peerID peer.ID, stream network.Stream) {
 // removeEntry removes a stream entry from the cache
 func (sc *StructStreamCache) removeEntry(peerID peer.ID) {
 	if entry, exists := sc.StreamCache.Streams[peerID]; exists {
-		entry.Stream.Close()
+		if err := entry.Stream.Close(); err != nil {
+			fmt.Printf("Failed to close stream for peer %s: %v\n", peerID, err)
+		}
 		delete(sc.StreamCache.Streams, peerID)
 		sc.removeFromOrder(peerID)
 	}

AVC/NodeSelection/pkg/selection/service.go

@@ -25,7 +25,11 @@ func GetBuddyNodes(
 		return nil, err
 	}
 	// fmt.Printf("Debugging 1\n")
-	defer peerClient.Close()
+	defer func() {
+		if closeErr := peerClient.Close(); closeErr != nil {
+			fmt.Println("⚠️ Failed to close peer client:", closeErr)
+		}
+	}()
 
 	fmt.Println("📡 Connected to peer directory at", peerDirAddress)
 

Block/gRPCclient.go

@@ -882,7 +882,9 @@ func InitMempoolClient(logger_ctx context.Context, address string) error {
 // CloseMempoolClient closes the global mempool client
 func CloseMempoolClient() {
 	if globalMempoolClient != nil {
-		globalMempoolClient.Close()
+		if err := globalMempoolClient.Close(); err != nil {
+			fmt.Printf("Failed to close global mempool client: %v\n", err)
+		}
 		globalMempoolClient = nil
 	}
 }

CA/ImmuDB_CA/ImmuDB_CA.go

@@ -204,6 +204,10 @@ func writePEM(path, blockType string, derBytes []byte) error {
 	if err != nil {
 		return fmt.Errorf("open %q: %w", path, err)
 	}
-	defer f.Close()
+	defer func() {
+		if closeErr := f.Close(); closeErr != nil {
+			fmt.Printf("Error closing PEM file %q: %v\n", path, closeErr)
+		}
+	}()
 	return pem.Encode(f, &pem.Block{Type: blockType, Bytes: derBytes})
 }

CLI/CLI.go

@@ -364,7 +364,11 @@ func (h *CommandHandler) handleSeedNodeStats(parts []string) {
 		fmt.Println("💡 Check if the seed node is running and accessible.")
 		return
 	}
-	defer client.Close()
+	defer func() {
+		if closeErr := client.Close(); closeErr != nil {
+			fmt.Printf("⚠️  Failed to close seed node client: %v\n", closeErr)
+		}
+	}()
 
 	fmt.Println("✅ Successfully connected to seed node!")
 
@@ -898,7 +902,11 @@ func (h *CommandHandler) handleListAliases() {
 		fmt.Printf("❌ Failed to connect to seed node: %v\n", err)
 		return
 	}
-	defer client.Close()
+	defer func() {
+		if closeErr := client.Close(); closeErr != nil {
+			fmt.Printf("⚠️  Failed to close client: %v\n", closeErr)
+		}
+	}()
 
 	// Get current node's peer ID
 	currentPeerID := h.Node.Host.ID().String()
@@ -960,7 +968,11 @@ func (h *CommandHandler) handleDiscoverNeighbors() {
 		fmt.Printf("❌ Failed to connect to seed node: %v\n", err)
 		return
 	}
-	defer client.Close()
+	defer func() {
+		if closeErr := client.Close(); closeErr != nil {
+			fmt.Printf("⚠️  Failed to close client: %v\n", closeErr)
+		}
+	}()
 
 	// Perform neighbor discovery
 	err = client.DiscoverAndAddNeighbors(h.Node.Host, h.NodeManager)