From 7ce4297e9f10c3a1263fb43c69b75df71423083a Mon Sep 17 00:00:00 2001
From: Virgil <virgil@lethean.io>
Date: Fri, 3 Apr 2026 22:57:00 +0000
Subject: [PATCH] Handle empty DNS discovery as a no-op

---
 service.go      | 18 ++++++++----------
 service_test.go | 19 +++++++++++++++++++
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/service.go b/service.go
index 880e234..6ab764c 100644
--- a/service.go
+++ b/service.go
@@ -251,11 +251,6 @@ func (service *Service) resolveHSDClient(client *HSDClient) (*HSDClient, error)
 }
 
 func (service *Service) DiscoverFromChainAliases(ctx context.Context, client *HSDClient) error {
-	effectiveHSDClient, err := service.resolveHSDClient(client)
-	if err != nil {
-		return err
-	}
-
 	aliases, found, err := service.discoverAliasesFromSources(
 		ctx,
 		service.chainAliasActionCaller,
@@ -270,6 +265,10 @@ func (service *Service) DiscoverFromChainAliases(ctx context.Context, client *HS
 	if !found {
 		return nil
 	}
+	effectiveHSDClient, err := service.resolveHSDClient(client)
+	if err != nil {
+		return err
+	}
 	if len(aliases) == 0 {
 		now := time.Now()
 		fingerprint := aliasFingerprint(aliases)
@@ -457,11 +456,6 @@ func parseActionAliasRecord(record map[string]any) (string, error) {
 //		dns.NewHSDClient(dns.HSDClientOptions{URL: "http://127.0.0.1:14037"}),
 //	)
 func (service *Service) DiscoverFromMainchainAliases(ctx context.Context, chainClient *MainchainAliasClient, hsdClient *HSDClient) error {
-	effectiveHSDClient, err := service.resolveHSDClient(hsdClient)
-	if err != nil {
-		return err
-	}
-
 	effectiveChainClient := chainClient
 	if effectiveChainClient == nil {
 		effectiveChainClient = service.mainchainAliasClient
@@ -497,6 +491,10 @@ func (service *Service) DiscoverFromMainchainAliases(ctx context.Context, chainC
 	if !found {
 		return nil
 	}
+	effectiveHSDClient, err := service.resolveHSDClient(hsdClient)
+	if err != nil {
+		return err
+	}
 	if len(aliases) == 0 {
 		now := time.Now()
 		fingerprint := aliasFingerprint(aliases)
diff --git a/service_test.go b/service_test.go
index 71aa1e7..3f98ebb 100644
--- a/service_test.go
+++ b/service_test.go
@@ -1615,6 +1615,25 @@ func TestServiceDiscoverReturnsNilWithoutDiscoverer(t *testing.T) {
 	}
 }
 
+func TestServiceDiscoverAliasesReturnsNilWithoutDiscovererOrHSDClient(t *testing.T) {
+	service := NewService(ServiceOptions{
+		Records: map[string]NameRecords{
+			"gateway.charon.lthn": {
+				A: []string{"10.10.10.10"},
+			},
+		},
+	})
+
+	if err := service.DiscoverAliases(context.Background()); err != nil {
+		t.Fatalf("expected discover aliases to no-op without sources or HSD client: %v", err)
+	}
+
+	result, ok := service.Resolve("gateway.charon.lthn")
+	if !ok || len(result.A) != 1 || result.A[0] != "10.10.10.10" {
+		t.Fatalf("expected cached record to remain intact, got %#v (ok=%t)", result, ok)
+	}
+}
+
 func TestServiceServeResolvesAAndAAAARecords(t *testing.T) {
 	service := NewService(ServiceOptions{
 		Records: map[string]NameRecords{