fix bug

FastGithub.Dns/DnsServiceCollectionExtensions.cs

@@ -19,9 +19,9 @@ namespace FastGithub
         {
             var assembly = typeof(DnsServiceCollectionExtensions).Assembly;
             return services               
-                .AddGithubScanner(configuration)
                 .AddServiceAndOptions(assembly, configuration)
-                .AddHostedService<DnsHostedService>();
+                .AddHostedService<DnsHostedService>()
+                .AddGithubScanner(configuration);
         }
     }
 }

FastGithub.Scanner/GithubContextHashSet.cs

@@ -2,7 +2,7 @@
 
 namespace FastGithub.Scanner
 {
-    class GithubContextHashSet : HashSet<GithubContext>
+    sealed class GithubContextHashSet : HashSet<GithubContext>
     {
         public readonly object SyncRoot = new();
     }

FastGithub.Scanner/GithubOptions.cs

@@ -3,7 +3,7 @@
 namespace FastGithub.Scanner
 {
     [Options("Github")]
-    class GithubOptions
+    sealed class GithubOptions
     {
         public TimeSpan ScanAllInterval { get; set; } = TimeSpan.FromHours(12d);
 

FastGithub.Scanner/GithubScanService.cs

@@ -73,9 +73,6 @@ namespace FastGithub.Scanner
         {
             if (domain.Contains("github", StringComparison.OrdinalIgnoreCase))
             {
-                return default;
-            }
-
                 lock (this.results.SyncRoot)
                 {
                     return this.results
@@ -85,5 +82,8 @@ namespace FastGithub.Scanner
                         .FirstOrDefault();
                 }
             }
+
+            return default;
+        }
     }
 }

FastGithub.Scanner/Meta.cs

@@ -6,7 +6,7 @@ using System.Text.Json.Serialization;
 
 namespace FastGithub.Scanner
 {
-    class Meta
+    sealed class Meta
     {
         [JsonPropertyName("hooks")]
         public string[] Hooks { get; set; } = Array.Empty<string>();