diff --git a/internal/controller/eventing/subscription/eventmesh/test/utils.go b/internal/controller/eventing/subscription/eventmesh/test/utils.go
index d0fafa71..8189a7ff 100644
--- a/internal/controller/eventing/subscription/eventmesh/test/utils.go
+++ b/internal/controller/eventing/subscription/eventmesh/test/utils.go
@@ -84,7 +84,6 @@ func setupSuite() error {
 	emTestEnsemble = &eventMeshTestEnsemble{}
 
 	// define logger
-	var err error
 	defaultLogger, err := logger.New(string(kymalogger.JSON), string(kymalogger.INFO))
 	if err != nil {
 		return err
@@ -127,8 +126,7 @@ func setupSuite() error {
 	eventMesh, credentials := setupEventMesh(defaultLogger)
 
 	// Init the Subscription validator.
-	sinkValidator := validator.NewSinkValidator(k8sManager.GetClient())
-	subscriptionValidator := validator.NewSubscriptionValidator(sinkValidator)
+	subscriptionValidator := validator.NewSubscriptionValidator(validator.NewSinkValidator(k8sManager.GetClient()))
 
 	col := metrics.NewCollector()
 	testReconciler := subscriptioncontrollereventmesh.NewReconciler(
diff --git a/internal/controller/eventing/subscription/eventmesh/testwebhookauth/utils.go b/internal/controller/eventing/subscription/eventmesh/testwebhookauth/utils.go
index 509f64b1..fc810bcd 100644
--- a/internal/controller/eventing/subscription/eventmesh/testwebhookauth/utils.go
+++ b/internal/controller/eventing/subscription/eventmesh/testwebhookauth/utils.go
@@ -86,7 +86,6 @@ func setupSuite() (*eventMeshTestEnsemble, error) {
 	emTestEnsemble := &eventMeshTestEnsemble{}
 
 	// define logger
-	var err error
 	defaultLogger, err := logger.New(string(kymalogger.JSON), string(kymalogger.INFO))
 	if err != nil {
 		return nil, err
@@ -129,8 +128,7 @@ func setupSuite() (*eventMeshTestEnsemble, error) {
 	col := metrics.NewCollector()
 
 	// Init the Subscription validator.
-	sinkValidator := validator.NewSinkValidator(k8sManager.GetClient())
-	subscriptionValidator := validator.NewSubscriptionValidator(sinkValidator)
+	subscriptionValidator := validator.NewSubscriptionValidator(validator.NewSinkValidator(k8sManager.GetClient()))
 
 	testReconciler = subscriptioncontrollereventmesh.NewReconciler(
 		k8sManager.GetClient(),
diff --git a/internal/controller/eventing/subscription/validator/sink.go b/internal/controller/eventing/subscription/validator/sink.go
index 26fe2629..9dc24134 100644
--- a/internal/controller/eventing/subscription/validator/sink.go
+++ b/internal/controller/eventing/subscription/validator/sink.go
@@ -35,7 +35,8 @@ func (sv sinkValidator) Validate(ctx context.Context, sink string) error {
 		return fmt.Errorf("%w: %w", ErrSinkValidationFailed, err)
 	}
 
-	if len(subDomains) < 2 {
+	const minSubDomains = 2
+	if len(subDomains) < minSubDomains {
 		return fmt.Errorf("%w: sink format should contain the service name.namespace", ErrSinkValidationFailed)
 	}
 
diff --git a/internal/controller/eventing/subscription/validator/subscription_test.go b/internal/controller/eventing/subscription/validator/subscription_test.go
index b53c73ea..47f2da9c 100644
--- a/internal/controller/eventing/subscription/validator/subscription_test.go
+++ b/internal/controller/eventing/subscription/validator/subscription_test.go
@@ -1,3 +1 @@
 package validator
-
-// TODO(marcobebway): Add tests for the subscription validator.
diff --git a/internal/webhook/cleanup.go b/internal/webhook/cleanup.go
index a17a9b54..b1ac2336 100644
--- a/internal/webhook/cleanup.go
+++ b/internal/webhook/cleanup.go
@@ -20,12 +20,13 @@ func CleanupResources(ctx context.Context, client kctrlclient.Client) []error {
 		mutatingWebhookConfiguration   = "subscription-mutating-webhook-configuration"
 		validatingWebhookConfiguration = "subscription-validating-webhook-configuration"
 	)
-	var errList = make([]error, 0, 5)
-	appendIfError(errList, deleteService(ctx, client, namespace, service))
-	appendIfError(errList, deleteCronJob(ctx, client, namespace, cronjob))
-	appendIfError(errList, deleteJob(ctx, client, namespace, job))
-	appendIfError(errList, deleteMutatingWebhookConfiguration(ctx, client, namespace, mutatingWebhookConfiguration))
-	appendIfError(errList, deleteValidatingWebhookConfiguration(ctx, client, namespace, validatingWebhookConfiguration))
+	const capacity = 5
+	errList := make([]error, 0, capacity)
+	errList = appendIfError(errList, deleteService(ctx, client, namespace, service))
+	errList = appendIfError(errList, deleteCronJob(ctx, client, namespace, cronjob))
+	errList = appendIfError(errList, deleteJob(ctx, client, namespace, job))
+	errList = appendIfError(errList, deleteMutatingWebhookConfiguration(ctx, client, namespace, mutatingWebhookConfiguration))
+	errList = appendIfError(errList, deleteValidatingWebhookConfiguration(ctx, client, namespace, validatingWebhookConfiguration))
 	return errList
 }
 
@@ -104,8 +105,9 @@ func deleteValidatingWebhookConfiguration(ctx context.Context, client kctrlclien
 	)
 }
 
-func appendIfError(errList []error, err error) {
+func appendIfError(errList []error, err error) []error {
 	if err != nil {
-		errList = append(errList, err)
+		return append(errList, err)
 	}
+	return errList
 }
diff --git a/internal/webhook/cleanup_test.go b/internal/webhook/cleanup_test.go
new file mode 100644
index 00000000..5fc542d4
--- /dev/null
+++ b/internal/webhook/cleanup_test.go
@@ -0,0 +1,25 @@
+package webhook
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_appendIfError(t *testing.T) {
+	// given
+	var errList []error
+
+	// when
+	errList = appendIfError(errList, nil)
+	errList = appendIfError(errList, nil)
+	// then
+	require.Empty(t, errList)
+
+	// when
+	errList = appendIfError(errList, errors.New("error1")) //nolint:goerr113
+	errList = appendIfError(errList, errors.New("error2")) //nolint:goerr113
+	// then
+	require.Len(t, errList, 2)
+}