Added unit test for SmtpClient .cctor

jstedfast · Jan 15, 2024 · 0bb3367 · 0bb3367
1 parent 8b9bfd0
commit 0bb3367
Show file tree

Hide file tree

Showing 2 changed files with 47 additions and 21 deletions.
diff --git a/MailKit/Net/Smtp/SmtpClient.cs b/MailKit/Net/Smtp/SmtpClient.cs
@@ -92,32 +92,36 @@ enum SmtpCommand {
 		bool secure;
 		Uri uri;
 
-		static SmtpClient ()
+		internal static string GetSafeHostName (string hostName)
 		{
-			string hostName;
-
-			try {
-				hostName = IPGlobalProperties.GetIPGlobalProperties ().HostName;
-				var idn = new IdnMapping ();
-
-				if (!string.IsNullOrEmpty (hostName)) {
-					hostName = hostName.Replace ('_', '-');
+			var idn = new IdnMapping ();
 
-					try {
-						hostName = idn.GetAscii (hostName);
-					} catch (ArgumentException) {
-						// This can happen if the hostName contains illegal unicode characters.
-						var ascii = new StringBuilder ();
-						for (int i = 0; i < hostName.Length; i++) {
-							if (hostName[i] <= 0x7F)
-								ascii.Append (hostName[i]);
-						}
+			if (!string.IsNullOrEmpty (hostName)) {
+				hostName = hostName.Replace ('_', '-');
 
-						hostName = ascii.Length > 0 ? ascii.ToString () : null;
+				try {
+					return idn.GetAscii (hostName);
+				} catch (ArgumentException) {
+					// This can happen if the hostName contains illegal unicode characters.
+					var ascii = new StringBuilder ();
+					for (int i = 0; i < hostName.Length; i++) {
+						if (hostName[i] <= 0x7F)
+							ascii.Append (hostName[i]);
 					}
-				} else {
-					hostName = null;
+
+					return ascii.Length > 0 ? ascii.ToString () : null;
 				}
+			} else {
+				return null;
+			}
+		}
+
+		static SmtpClient ()
+		{
+			string hostName;
+
+			try {
+				hostName = GetSafeHostName (IPGlobalProperties.GetIPGlobalProperties ().HostName);
 			} catch {
 				hostName = null;
 			}

diff --git a/UnitTests/Net/Smtp/SmtpClientTests.cs b/UnitTests/Net/Smtp/SmtpClientTests.cs
@@ -228,6 +228,28 @@ public void TestArgumentExceptions ()
 			}
 		}
 
+		[Test]
+		public void TestGetSafeHostName ()
+		{
+			string safe;
+
+			safe = SmtpClient.GetSafeHostName (null);
+			Assert.That (safe, Is.Null);
+
+			safe = SmtpClient.GetSafeHostName ("domain.com");
+			Assert.That (safe, Is.EqualTo ("domain.com"));
+
+			safe = SmtpClient.GetSafeHostName ("underscore_domain.com");
+			Assert.That (safe, Is.EqualTo ("underscore-domain.com"));
+
+			safe = SmtpClient.GetSafeHostName ("名がドメイン.com");
+			Assert.That (safe, Is.EqualTo ("xn--v8jxj3d1dzdz08w.com"));
+
+			var toolong = new string ('a', 256) + '.' + new string ('b', 256) + '.' + "com";
+			safe = SmtpClient.GetSafeHostName (toolong);
+			Assert.That (safe, Is.EqualTo (toolong));
+		}
+
 		static void AssertDefaultValues (string host, int port, SecureSocketOptions options, Uri expected)
 		{
 			SmtpClient.ComputeDefaultValues (host, ref port, ref options, out Uri uri, out bool starttls);