From f281771f3efe286623f9be623922dd1cf43ef4f4 Mon Sep 17 00:00:00 2001
From: Marek Habersack <grendel@twistedcode.net>
Date: Wed, 10 Apr 2019 20:10:37 +0200
Subject: [PATCH] [tests] More network resilience for tests

Context: 608d950a703ddb527258565c2a0705aa37f71789
Context: 34dfc6d71d590183f0077b69bbd61964f8879b97

SslTests notoriously fail for reasons not related to the subject of the test,
thus creating false negatives when our bots flag the related builds/PRs as red
while the failure can/should be ignored.

Wrap the tests in code which ignores the most common failures we can safely
ignore.

Additionally, slightly improve connection error handling in
AndroidHttpClientHandler tests.
---
 src/Mono.Android/Test/System.Net/SslTest.cs   | 73 +++++++++++++++++--
 .../AndroidClientHandlerTests.cs              | 31 ++++++--
 2 files changed, 90 insertions(+), 14 deletions(-)

diff --git a/src/Mono.Android/Test/System.Net/SslTest.cs b/src/Mono.Android/Test/System.Net/SslTest.cs
index e271066c950..be0842ebc57 100644
--- a/src/Mono.Android/Test/System.Net/SslTest.cs
+++ b/src/Mono.Android/Test/System.Net/SslTest.cs
@@ -11,7 +11,19 @@
 namespace System.NetTests {
 
 	[TestFixture, Category ("InetAccess")]
-	public class SslTest {
+	public class SslTest
+	{
+		bool ShouldIgnoreException (WebException wex)
+		{
+			switch (wex.Status) {
+				case WebExceptionStatus.ConnectFailure:
+				case WebExceptionStatus.NameResolutionFailure:
+				case WebExceptionStatus.Timeout:
+					return true;
+			}
+
+			return false;
+		}
 
 		// https://xamarin.desk.com/agent/case/35534
 		[Test]
@@ -41,16 +53,33 @@ public void SslWithinTasksShouldWork ()
 			thread.Join ();
 
 			ServicePointManager.ServerCertificateValidationCallback = cb;
+			var wex = (exception as AggregateException)?.InnerException as WebException;
+			if (wex != null) {
+				if (ShouldIgnoreException (wex)) {
+					Assert.Ignore ($"Ignoring network failure: {wex}");
+					return;
+				}
+				throw wex;
+			}
+
+			if (exception != null)
+				throw exception;
+
 			Assert.AreEqual (TaskStatus.RanToCompletion, status);
 		}
 
 		[Test]
 		public void HttpsShouldWork ()
+		{
+			RunIgnoringWebException (DoHttpsShouldWork);
+		}
+
+		void DoHttpsShouldWork ()
 		{
 			// string url = "https://bugzilla.novell.com/show_bug.cgi?id=634817";
 			string url = "https://encrypted.google.com/";
 			// string url = "http://slashdot.org";
-			var request = (HttpWebRequest) WebRequest.Create(url);
+			HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);
 			request.Method = "GET";
 			var response = (HttpWebResponse) request.GetResponse ();
 			int len = 0;
@@ -62,18 +91,48 @@ public void HttpsShouldWork ()
 					len += n;
 				}
 			}
+
 			Assert.IsTrue (len > 0);
 		}
 
 		[Test (Description="Bug https://bugzilla.xamarin.com/show_bug.cgi?id=18962")]
 		public void VerifyTrustedCertificates ()
 		{
-			Assert.DoesNotThrow (() => {
-				var tcpClient = new TcpClient ("google.com", 443);
-				using (var ssl = new SslStream (tcpClient.GetStream (), false)) {
-					ssl.AuthenticateAsClient ("google.com");
+			Assert.DoesNotThrow (() => RunIgnoringWebException (DoVerifyTrustedCertificates), "Certificate validation");
+		}
+
+		void DoVerifyTrustedCertificates ()
+		{
+			var tcpClient = new TcpClient ("google.com", 443);
+			using (var ssl = new SslStream (tcpClient.GetStream (), false)) {
+				ssl.AuthenticateAsClient ("google.com");
+			}
+		}
+
+		void RunIgnoringWebException (Action test)
+		{
+			Exception ex = null;
+			WebException wex = null;
+
+			try {
+				test ();
+			} catch (AggregateException e) {
+				ex = e;
+				wex = e.InnerException as WebException;
+			} catch (WebException e) {
+				wex = e;
+			}
+
+			if (wex != null) {
+				if (ShouldIgnoreException (wex)) {
+					Assert.Ignore ($"Ignoring network failure: {wex.Status}");
+					return;
 				}
-			}, "Certificate validation");
+				throw wex;
+			}
+
+			if (ex != null)
+				throw ex;
 		}
 	}
 }
diff --git a/src/Mono.Android/Test/Xamarin.Android.Net/AndroidClientHandlerTests.cs b/src/Mono.Android/Test/Xamarin.Android.Net/AndroidClientHandlerTests.cs
index 43d51b6f97b..c444662a85b 100644
--- a/src/Mono.Android/Test/Xamarin.Android.Net/AndroidClientHandlerTests.cs
+++ b/src/Mono.Android/Test/Xamarin.Android.Net/AndroidClientHandlerTests.cs
@@ -151,7 +151,7 @@ protected Task<HttpResponseMessage> ConnectIgnoreFailure (Func<Task<HttpResponse
 			try {
 				return connector ();
 			} catch (AggregateException ex) {
-				if (IgnoreIfConnectionFailed (ex.InnerException as WebException, out connectionFailed))
+				if (IgnoreIfConnectionFailed (ex, out connectionFailed))
 					return null;
 				throw;
 			}
@@ -163,24 +163,41 @@ protected void RunIgnoringNetworkIssues (Action runner, out bool connectionFaile
 			try {
 				runner ();
 			} catch (AggregateException ex) {
-				if (IgnoreIfConnectionFailed (ex.InnerException as WebException, out connectionFailed))
+				if (IgnoreIfConnectionFailed (ex, out connectionFailed))
 					return;
 				throw;
 			}
 		}
 
+		bool IgnoreIfConnectionFailed (AggregateException aex, out bool connectionFailed)
+		{
+			if (IgnoreIfConnectionFailed (aex.InnerException as HttpRequestException, out connectionFailed))
+				return true;
+
+			return IgnoreIfConnectionFailed (aex.InnerException as WebException, out connectionFailed);
+		}
+
+		bool IgnoreIfConnectionFailed (HttpRequestException hrex, out bool connectionFailed)
+		{
+			return IgnoreIfConnectionFailed (hrex?.InnerException as WebException, out connectionFailed);
+		}
+
 		bool IgnoreIfConnectionFailed (WebException wex, out bool connectionFailed)
 		{
 			connectionFailed = false;
 			if (wex == null)
 				return false;
 
-			if (wex.Status != WebExceptionStatus.ConnectFailure)
-				return false;
+			switch (wex.Status) {
+				case WebExceptionStatus.ConnectFailure:
+				case WebExceptionStatus.NameResolutionFailure:
+				case WebExceptionStatus.Timeout:
+					connectionFailed = true;
+					Assert.Ignore ($"Ignoring network failure: {wex}");
+					return true;
+			}
 
-			connectionFailed = true;
-			Assert.Ignore ($"Failed to connect to server. {wex}");
-			return true;
+			return false;
 		}
 	}