fix(nats): resolve golangci-lint failures (gosec G118, revive)

pkg/events/nats.go

@@ -48,7 +48,7 @@ type NATSBus struct {
 	durable string // durable consumer name prefix (per consuming service)
 
 	mu       sync.Mutex
-	cancels  []context.CancelFunc
+	stop     chan struct{} // closed by Close to trigger early consumer drain
 	consumes []jetstream.ConsumeContext
 }
 
@@ -100,7 +100,7 @@ func NewNATSBus(url, durableName string, workers int, m *metrics.Metrics, log *z
 		return nil, fmt.Errorf("jetstream init: %w", err)
 	}
 
-	b := &NATSBus{conn: conn, js: js, log: log, m: m, workers: workers, durable: durableName}
+	b := &NATSBus{conn: conn, js: js, log: log, m: m, workers: workers, durable: durableName, stop: make(chan struct{})}
 
 	// Ensure every known stream exists. CreateOrUpdateStream is idempotent, so
 	// every service can call this safely on boot regardless of start order.
@@ -277,18 +277,19 @@ func (b *NATSBus) startConsumers(ctx context.Context, handler Handler, topics ..
 			return fmt.Errorf("consume %s: %w", durable, err)
 		}
 
-		// Graceful shutdown: when ctx ends, stop pulling, drain the pool, then
-		// stop the consume context.
-		shutdownCtx, cancel := context.WithCancel(ctx)
+		// Graceful shutdown: when the subscribe ctx ends OR Close is called,
+		// stop pulling, drain the pool, then stop the consume context.
 		go func() {
-			<-shutdownCtx.Done()
+			select {
+			case <-ctx.Done():
+			case <-b.stop:
+			}
 			consume.Stop() // stop delivering new messages
 			close(work)    // let workers drain remaining buffered messages
 			wg.Wait()
 		}()
 
 		b.mu.Lock()
-		b.cancels = append(b.cancels, cancel)
 		b.consumes = append(b.consumes, consume)
 		b.mu.Unlock()
 	}
@@ -356,16 +357,18 @@ func (b *NATSBus) process(ctx context.Context, topic string, handler Handler, ms
 	}
 }
 
-// Close stops all consumers and drains the NATS connection.
+// Close stops all consumers and drains the NATS connection. It is safe to call
+// once; the stop channel signals each consumer's drain goroutine to wind down.
 func (b *NATSBus) Close() error {
 	b.mu.Lock()
-	for _, cancel := range b.cancels {
-		cancel()
+	select {
+	case <-b.stop: // already closed
+	default:
+		close(b.stop)
 	}
 	for _, c := range b.consumes {
 		c.Stop()
 	}
-	b.cancels = nil
 	b.consumes = nil
 	b.mu.Unlock()
 

pkg/events/nats_test.go

@@ -49,7 +49,7 @@ func TestNATSPublishConsumeAck(t *testing.T) {
 	defer cancel()
 
 	gotTrace := make(chan trace.TraceID, 1)
-	handler := func(hctx context.Context, e Event) error {
+	handler := func(hctx context.Context, _ Event) error {
 		gotTrace <- trace.SpanContextFromContext(hctx).TraceID()
 		return nil
 	}