Re-enable components E2E tests on the CI

Author: Ryan Nowak

src/Components/test/E2ETest/Infrastructure/ServerFixtures/ServerFixture.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.ExceptionServices;
 using System.Threading;
 
 namespace Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures
@@ -52,13 +53,30 @@ protected static void RunInBackgroundThread(Action action)
         {
             var isDone = new ManualResetEvent(false);
 
+            ExceptionDispatchInfo edi = null;
             new Thread(() =>
             {
-                action();
+                try
+                {
+                    action();
+                }
+                catch (Exception ex)
+                {
+                    edi = ExceptionDispatchInfo.Capture(ex);
+                }
+
                 isDone.Set();
             }).Start();
 
-            isDone.WaitOne();
+            if (!isDone.WaitOne(TimeSpan.FromSeconds(10)))
+            {
+                throw new TimeoutException("Timed out waiting for: " + action);
+            }
+
+            if (edi != null)
+            {
+                throw edi.SourceException;
+            }
         }
     }
 }

src/Components/test/E2ETest/Infrastructure/ServerFixtures/WebHostServerFixture.cs

@@ -24,6 +24,7 @@ public override void Dispose()
         {
             // This can be null if creating the webhost throws, we don't want to throw here and hide
             // the original exception.
+            Host?.Dispose();
             Host?.StopAsync();
         }
 

src/Components/test/E2ETest/Microsoft.AspNetCore.Components.E2ETests.csproj

@@ -7,12 +7,16 @@
     <TargetFramework>netcoreapp3.0</TargetFramework>
     <TestGroupName>Components.E2ETests</TestGroupName>
 
-    <SkipTests Condition="$(ContinuousIntegrationBuild) == 'true'" >true</SkipTests>
     <!-- https://github.com/aspnet/AspNetCore/issues/6857 -->
     <BuildHelixPayload>false</BuildHelixPayload>
+    
+    <!-- Run on platforms where we support Selenium -->
+    <SkipTests Condition="'$(SeleniumE2ETestsSupported)' != 'true'">true</SkipTests>
 
     <!-- Tests do not work on Helix or when bin/ directory is not in project directory due to undeclared dependency on test content. -->
     <BaseOutputPath />
+    
+    
     <OutputPath />
 
   </PropertyGroup>