✨ Refactor application initialization to load configuration and enhance message processing. Introduce effective subscription topic handling and improve error management in NATS consumer. Update tests for publisher error handling and add new dependency injection method for app initialization.

internal/app/processor.go

@@ -5,6 +5,7 @@ import (
 	"caatsm/internal/adapter/parser"
 	"context"
 	"fmt"
+
 	"go.uber.org/zap"
 )
 
@@ -33,7 +34,7 @@ func NewMessageProcessor(
 
 // Handle processes a message
 func (p *MessageProcessor) Handle(ctx context.Context, raw []byte, msgID string) error {
-	if raw == nil || len(raw) == 0 {
+	if len(raw) == 0 {
 		return Permanent(fmt.Errorf("empty message"))
 	}
 
@@ -50,7 +51,7 @@ func (p *MessageProcessor) Handle(ctx context.Context, raw []byte, msgID string)
 	if !parsed.Parsed {
 		p.logger.Info("Message not parsed",
 			zap.String("msg_id", msgID),
-			zap.String("content", parsed.Content),
+			zap.String("content_preview", truncateContent(parsed.Content, 200)),
 		)
 	} else {
 		p.logger.Info("Message parsed successfully",
@@ -72,9 +73,19 @@ func (p *MessageProcessor) Handle(ctx context.Context, raw []byte, msgID string)
 			zap.String("msg_id", msgID),
 			zap.Error(err),
 		)
-		// Return error to trigger NAK and retry
-		return fmt.Errorf("failed to publish message: %w", err)
+		// Mark as permanent so the consumer will ack instead of retrying
+		return Permanent(fmt.Errorf("failed to publish message: %w", err))
 	}
 
 	return nil
 }
+
+func truncateContent(content string, limit int) string {
+	if limit <= 0 || len(content) <= limit {
+		return content
+	}
+	if limit <= 3 {
+		return content[:limit]
+	}
+	return content[:limit-3] + "..."
+}

internal/app/processor_test.go

@@ -94,7 +94,7 @@ func TestHandleSuccessSetsUuidAndPublishes(t *testing.T) {
 	}
 }
 
-func TestHandlePublisherErrorIsRetriable(t *testing.T) {
+func TestHandlePublisherErrorIsPermanent(t *testing.T) {
 	parsed := domain.NewParsedMessage()
 	parsed.Parsed = true
 
@@ -106,8 +106,8 @@ func TestHandlePublisherErrorIsRetriable(t *testing.T) {
 	if err == nil {
 		t.Fatalf("expected error when publisher fails")
 	}
-	if IsPermanent(err) {
-		t.Fatalf("publisher failure should not be permanent")
+	if !IsPermanent(err) {
+		t.Fatalf("publisher failure should be permanent")
 	}
 	if len(repo.inserted) != 1 {
 		t.Fatalf("expected message to insert before publish failure")