From a406bfd86fbd1245f1064bc2518a9b5e5067e07d Mon Sep 17 00:00:00 2001
From: John Luo <jt.luo@mail.utoronto.ca>
Date: Fri, 25 Mar 2016 17:11:21 -0700
Subject: [PATCH] Add addtional test and some comments

---
 .../WebHostBuilder.cs                         |  4 ++--
 .../WebHostBuilderTests.cs                    | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Hosting/WebHostBuilder.cs b/src/Microsoft.AspNetCore.Hosting/WebHostBuilder.cs
index 92a6377e63..ff5494b9d6 100644
--- a/src/Microsoft.AspNetCore.Hosting/WebHostBuilder.cs
+++ b/src/Microsoft.AspNetCore.Hosting/WebHostBuilder.cs
@@ -221,8 +221,8 @@ namespace Microsoft.AspNetCore.Hosting
                 configureLogging(_loggerFactory);
             }
 
-            services.AddSingleton(_loggerFactory);
-            services.AddLogging();
+            services.AddSingleton(_loggerFactory); //The configured ILoggerFactory is added as a singleton here. AddLogging below will not add an additional one.
+            services.AddLogging(); //This is required to add ILogger of T.
 
             services.AddTransient<IStartupLoader, StartupLoader>();
 
diff --git a/test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs b/test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs
index ce4ad8c0f4..14531d07a0 100644
--- a/test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs
+++ b/test/Microsoft.AspNetCore.Hosting.Tests/WebHostBuilderTests.cs
@@ -169,6 +169,26 @@ namespace Microsoft.AspNetCore.Hosting
             Assert.Same(loggerFactory, host.Services.GetService<ILoggerFactory>());
         }
 
+        [Fact]
+        public void MultipleConfigureLoggingInvokedInOrder()
+        {
+            var callCount = 0; //Verify ordering
+            var hostBuilder = new WebHostBuilder()
+                .ConfigureLogging(loggerFactory =>
+                {
+                    Assert.Equal(0, callCount++);
+                })
+                .ConfigureLogging(loggerFactory =>
+                {
+                    Assert.Equal(1, callCount++);
+                })
+                .UseServer(new TestServer())
+                .UseStartup<StartupNoServices>();
+
+            var host = (WebHost)hostBuilder.Build();
+            Assert.Equal(2, callCount);
+        }
+
         [Fact]
         public void DefaultHostingConfigurationDoesNotCaptureStartupErrors()
         {