Move IDN to different file, add test

DnsClientX.Tests/CompareProvidersResolve.cs

@@ -5,6 +5,7 @@ public class CompareProvidersResolve(ITestOutputHelper output) {
         [Theory]
         //[MemberData(nameof(TestData))]
         [InlineData("evotec.pl", DnsRecordType.A)]
+        [InlineData("www.bücher.de", DnsRecordType.A)]
         [InlineData("evotec.pl", DnsRecordType.SOA)]
         [InlineData("evotec.pl", DnsRecordType.DNSKEY)]
         [InlineData("sip.evotec.pl", DnsRecordType.CNAME)]

DnsClientX.Tests/QueryDnsByEndpoint.cs

@@ -42,7 +42,6 @@ public async void ShouldWorkForTXT(DnsEndpoint endpoint) {
         [InlineData(DnsEndpoint.OpenDNS)]
         [InlineData(DnsEndpoint.OpenDNSFamily)]
         public async void ShouldWorkForA(DnsEndpoint endpoint) {
-            var Client = new ClientX(endpoint);
             var response = await ClientX.QueryDns("evotec.pl", DnsRecordType.A, endpoint);
             foreach (DnsAnswer answer in response.Answers) {
                 Assert.True(answer.Name == "evotec.pl");

DnsClientX.Tests/QueryDnsIDN.cs

@@ -0,0 +1,28 @@
+namespace DnsClientX.Tests {
+    public class QueryDnsIDN {
+        [Theory]
+        [InlineData(DnsEndpoint.System)]
+        [InlineData(DnsEndpoint.SystemTcp)]
+        [InlineData(DnsEndpoint.Cloudflare)]
+        [InlineData(DnsEndpoint.CloudflareFamily)]
+        [InlineData(DnsEndpoint.CloudflareSecurity)]
+        [InlineData(DnsEndpoint.CloudflareWireFormat)]
+        [InlineData(DnsEndpoint.CloudflareWireFormatPost)]
+        [InlineData(DnsEndpoint.Google)]
+        [InlineData(DnsEndpoint.GoogleWireFormat)]
+        [InlineData(DnsEndpoint.GoogleWireFormatPost)]
+        [InlineData(DnsEndpoint.Quad9)]
+        [InlineData(DnsEndpoint.Quad9ECS)]
+        [InlineData(DnsEndpoint.Quad9Unsecure)]
+        [InlineData(DnsEndpoint.OpenDNS)]
+        [InlineData(DnsEndpoint.OpenDNSFamily)]
+        public async void ShouldWorkForA(DnsEndpoint endpoint) {
+            var response = await ClientX.QueryDns("www.bücher.de", DnsRecordType.A, endpoint);
+            foreach (DnsAnswer answer in response.Answers) {
+                Assert.True(answer.Name == "www.xn--bcher-kva.de");
+                Assert.True(answer.Type == DnsRecordType.A);
+                Assert.True(answer.Data.Length > 0);
+            }
+        }
+    }
+}

DnsClientX/DnsClientX.Resolve.cs

@@ -125,16 +125,5 @@ public async Task<DnsResponse[]> Resolve(string[] names, DnsRecordType type, boo
 
             return tasks.Select(task => task.Result).ToArray();
         }
-
-        /// <summary>
-        /// Converts a domain name to its Punycode representation. This is useful for internationalized domain names (IDNs).
-        /// For example www.bücher.de will be converted to www.xn--bcher-kva.de
-        /// </summary>
-        /// <param name="domainName"></param>
-        /// <returns></returns>
-        public static string ConvertToPunycode(string domainName) {
-            IdnMapping idn = new IdnMapping();
-            return idn.GetAscii(domainName);
-        }
     }
 }

DnsClientX/DnsClientX.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Net;
 using System.Net.Http;
 using System.Net.Http.Headers;
@@ -168,5 +169,16 @@ private HttpClient GetClient(DnsSelectionStrategy strategy) {
             }
             return client;
         }
+
+        /// <summary>
+        /// Converts a domain name to its Punycode representation. This is useful for internationalized domain names (IDNs).
+        /// For example www.bücher.de will be converted to www.xn--bcher-kva.de
+        /// </summary>
+        /// <param name="domainName"></param>
+        /// <returns></returns>
+        private static string ConvertToPunycode(string domainName) {
+            IdnMapping idn = new IdnMapping();
+            return idn.GetAscii(domainName);
+        }
     }
 }