Address the review comments

internal/connection/nats/connection.go

@@ -49,15 +49,15 @@ func (c *connection) isConnected() bool {
 	return c.conn.IsConnected()
 }
 
-func (c *connection) RegisterReconnectHandlerIfNotRegistered(handler natsio.ConnHandler) {
+func (c *connection) RegisterReconnectHandler(handler natsio.ConnHandler) {
 	if c.conn == nil || c.reconnectHandlerRegistered {
 		return
 	}
 	c.conn.SetReconnectHandler(handler)
 	c.reconnectHandlerRegistered = true
 }
 
-func (c *connection) RegisterDisconnectErrHandlerIfNotRegistered(handler natsio.ConnErrHandler) {
+func (c *connection) RegisterDisconnectErrHandler(handler natsio.ConnErrHandler) {
 	if c.conn == nil || c.disconnectErrHandlerRegistered {
 		return
 	}

internal/connection/nats/interface.go

@@ -12,9 +12,9 @@ type Interface interface {
 	// Disconnect disconnects the NATS connection.
 	Disconnect()
 
-	// RegisterReconnectHandlerIfNotRegistered registers a ReconnectHandler only if it was not registered before.
-	RegisterReconnectHandlerIfNotRegistered(natsio.ConnHandler)
+	// RegisterReconnectHandler registers a ReconnectHandler only if it was not registered before.
+	RegisterReconnectHandler(natsio.ConnHandler)
 
-	// RegisterDisconnectErrHandlerIfNotRegistered registers a DisconnectErrHandler only if it was not registered before.
-	RegisterDisconnectErrHandlerIfNotRegistered(natsio.ConnErrHandler)
+	// RegisterDisconnectErrHandler registers a DisconnectErrHandler only if it was not registered before.
+	RegisterDisconnectErrHandler(natsio.ConnErrHandler)
 }

internal/controller/operator/eventing/controller.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"os"
 	"strings"
 
 	natsio "github.com/nats-io/nats.go"
@@ -76,11 +75,10 @@ const (
 )
 
 var (
-	ErrSubscriptionExists       = errors.New(SubscriptionExistsErrMessage)
-	ErrUnsupportedBackedType    = errors.New("backend type not supported")
-	ErrNatsModuleMissing        = errors.New("NATS module has to be installed")
-	ErrAPIGatewayModuleMissing  = errors.New("API-Gateway module is needed for EventMesh backend. APIRules CRD is not installed")
-	ErrNilNATSConnectionBuilder = errors.New("connection builder for NATS backend is nil")
+	ErrSubscriptionExists      = errors.New(SubscriptionExistsErrMessage)
+	ErrUnsupportedBackedType   = errors.New("backend type not supported")
+	ErrNatsModuleMissing       = errors.New("NATS module has to be installed")
+	ErrAPIGatewayModuleMissing = errors.New("API-Gateway module is needed for EventMesh backend. APIRules CRD is not installed")
 )
 
 // Reconciler reconciles an Eventing object
@@ -575,11 +573,6 @@ func (r *Reconciler) reconcileNATSBackend(ctx context.Context,
 	}
 
 	if connErr := r.connectToNATS(eventingCR); connErr != nil {
-		if errors.Is(connErr, ErrNilNATSConnectionBuilder) {
-			r.namedLogger().Error(connErr)
-			os.Exit(1)
-		}
-
 		if errors.Is(connErr, natsconnectionerrors.ErrCannotConnect) {
 			return kctrl.Result{}, reconcile.TerminalError(
 				r.syncStatusWithNATSErr(ctx, eventingCR, connErr, log),
@@ -608,10 +601,6 @@ func (r *Reconciler) reconcileNATSBackend(ctx context.Context,
 // connectToNATS connects to NATS and returns an error if it failed.
 // It also registers handlers for reconnection and disconnection.
 func (r *Reconciler) connectToNATS(eventingCR *operatorv1alpha1.Eventing) error {
-	if r.natsConnectionBuilder == nil {
-		return ErrNilNATSConnectionBuilder
-	}
-
 	if r.natsConnection == nil {
 		r.natsConnection = r.natsConnectionBuilder.Build()
 	}
@@ -622,13 +611,13 @@ func (r *Reconciler) connectToNATS(eventingCR *operatorv1alpha1.Eventing) error
 
 	// At this point, it is safe to register handlers
 	// because the internal nats connection is initialized.
-	r.natsConnection.RegisterReconnectHandlerIfNotRegistered(
+	r.natsConnection.RegisterReconnectHandler(
 		func(_ *natsio.Conn) {
 			r.namedLogger().Debug("Handle NATS reconnection")
 			r.genericEvents <- event.GenericEvent{Object: eventingCR}
 		},
 	)
-	r.natsConnection.RegisterDisconnectErrHandlerIfNotRegistered(
+	r.natsConnection.RegisterDisconnectErrHandler(
 		func(_ *natsio.Conn, _ error) {
 			r.namedLogger().Debug("Handle NATS disconnection")
 			r.genericEvents <- event.GenericEvent{Object: eventingCR}

internal/controller/operator/eventing/integrationtests/natsconnection/integration_test.go

@@ -33,8 +33,8 @@ func Test_NATSConnection(t *testing.T) {
 				conn := &natsconnectionmocks.Connection{}
 				conn.On("Connect").Return(nil)
 				conn.On("IsConnected").Return(true)
-				conn.On("RegisterReconnectHandlerIfNotRegistered", mock.Anything).Return()
-				conn.On("RegisterDisconnectErrHandlerIfNotRegistered", mock.Anything).Return()
+				conn.On("RegisterReconnectHandler", mock.Anything).Return()
+				conn.On("RegisterDisconnectErrHandler", mock.Anything).Return()
 				return conn
 			},
 			wantMatches: gomega.And(
@@ -50,8 +50,8 @@ func Test_NATSConnection(t *testing.T) {
 				conn := &natsconnectionmocks.Connection{}
 				conn.On("Connect").Return(natsconnectionerrors.ErrCannotConnect)
 				conn.On("IsConnected").Return(false)
-				conn.On("RegisterReconnectHandlerIfNotRegistered", mock.Anything).Return()
-				conn.On("RegisterDisconnectErrHandlerIfNotRegistered", mock.Anything).Return()
+				conn.On("RegisterReconnectHandler", mock.Anything).Return()
+				conn.On("RegisterDisconnectErrHandler", mock.Anything).Return()
 				return conn
 			},
 			wantMatches: gomega.And(

test/utils/integration/integration.go

@@ -199,8 +199,8 @@ func NewTestEnvironment(config TestEnvironmentConfig, connMock *natsconnectionmo
 		connMock.On("Connect").Return(nil)
 		connMock.On("IsConnected").Return(true)
 		connMock.On("Disconnect").Return()
-		connMock.On("RegisterReconnectHandlerIfNotRegistered", mock.Anything).Return()
-		connMock.On("RegisterDisconnectErrHandlerIfNotRegistered", mock.Anything).Return()
+		connMock.On("RegisterReconnectHandler", mock.Anything).Return()
+		connMock.On("RegisterDisconnectErrHandler", mock.Anything).Return()
 	}
 
 	// create a new watcher