From a82daa221ad3c966484debc051ff548d59bc09b4 Mon Sep 17 00:00:00 2001
From: Jeffrey Stedfast <jestedfa@microsoft.com>
Date: Mon, 9 Dec 2024 19:33:12 -0500
Subject: [PATCH] Added more tests for WebProxyClient

---
 MailKit/Net/Proxy/WebProxyClient.cs        | 25 ++++++++++++++++++++--
 UnitTests/Net/Proxy/WebProxyClientTests.cs | 23 ++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/MailKit/Net/Proxy/WebProxyClient.cs b/MailKit/Net/Proxy/WebProxyClient.cs
index faabdc6618..fb782fd7bf 100644
--- a/MailKit/Net/Proxy/WebProxyClient.cs
+++ b/MailKit/Net/Proxy/WebProxyClient.cs
@@ -87,7 +87,7 @@ static NetworkCredential GetNetworkCredential (ICredentials credentials, Uri uri
 			return credentials.GetCredential (uri, "Basic");
 		}
 
-		static ProxyClient GetProxyClient (Uri proxyUri, ICredentials credentials)
+		internal static ProxyClient GetProxyClient (Uri proxyUri, ICredentials credentials)
 		{
 			var credential = GetNetworkCredential (credentials, proxyUri);
 
@@ -105,7 +105,28 @@ static ProxyClient GetProxyClient (Uri proxyUri, ICredentials credentials)
 				return new HttpProxyClient (proxyUri.Host, proxyUri.Port);
 			}
 
-			throw new NotImplementedException ($"The default system proxy does not support {proxyUri.Scheme}.");
+			if (proxyUri.Scheme.Equals ("socks4", StringComparison.OrdinalIgnoreCase)) {
+				if (credential != null)
+					return new Socks4Client (proxyUri.Host, proxyUri.Port, credential);
+
+				return new Socks4Client (proxyUri.Host, proxyUri.Port);
+			}
+
+			if (proxyUri.Scheme.Equals ("socks4a", StringComparison.OrdinalIgnoreCase)) {
+				if (credential != null)
+					return new Socks4aClient (proxyUri.Host, proxyUri.Port, credential);
+
+				return new Socks4aClient (proxyUri.Host, proxyUri.Port);
+			}
+
+			if (proxyUri.Scheme.Equals ("socks5", StringComparison.OrdinalIgnoreCase)) {
+				if (credential != null)
+					return new Socks5Client (proxyUri.Host, proxyUri.Port, credential);
+
+				return new Socks5Client (proxyUri.Host, proxyUri.Port);
+			}
+
+			throw new NotSupportedException ($"The default system proxy does not support {proxyUri.Scheme}.");
 		}
 
 		/// <summary>
diff --git a/UnitTests/Net/Proxy/WebProxyClientTests.cs b/UnitTests/Net/Proxy/WebProxyClientTests.cs
index 936b9365d9..da538f4f8e 100644
--- a/UnitTests/Net/Proxy/WebProxyClientTests.cs
+++ b/UnitTests/Net/Proxy/WebProxyClientTests.cs
@@ -66,6 +66,29 @@ public void TestArgumentExceptions ()
 			Assert.ThrowsAsync<ArgumentOutOfRangeException> (async () => await proxy.ConnectAsync ("www.google.com", 80, -ConnectTimeout));
 		}
 
+		[TestCase ("http://proxy:8080", null, null, typeof (HttpProxyClient))]
+		[TestCase ("http://proxy:8080", "user", "password", typeof (HttpProxyClient))]
+		[TestCase ("https://proxy:8080", null, null, typeof (HttpsProxyClient))]
+		[TestCase ("https://proxy:8080", "user", "password", typeof (HttpsProxyClient))]
+		[TestCase ("socks4://proxy:1080", null, null, typeof (Socks4Client))]
+		[TestCase ("socks4://proxy:1080", "user", "password", typeof (Socks4Client))]
+		[TestCase ("socks4a://proxy:1080", null, null, typeof (Socks4aClient))]
+		[TestCase ("socks4a://proxy:1080", "user", "password", typeof (Socks4aClient))]
+		[TestCase ("socks5://proxy:1080", null, null, typeof (Socks5Client))]
+		[TestCase ("socks5://proxy:1080", "user", "password", typeof (Socks5Client))]
+		[TestCase ("unsupported://proxy:1080", null, null, null)]
+		public void TestGetProxyClient (string proxyUri, string user, string password, Type expectedType)
+		{
+			var credentials = user != null ? new NetworkCredential (user, password) : null;
+
+			if (expectedType != null) {
+				var proxy = WebProxyClient.GetProxyClient (new Uri (proxyUri), credentials);
+				Assert.That (proxy, Is.InstanceOf (expectedType));
+			} else {
+				Assert.Throws<NotSupportedException> (() => WebProxyClient.GetProxyClient (new Uri (proxyUri), credentials));
+			}
+		}
+
 		[Test]
 		public void TestConnect ()
 		{