Use a ChainedConfigurationSource in WebApplicationBuilder

src/DefaultBuilder/DefaultBuilder.slnf

@@ -10,15 +10,31 @@
       "src\\Hosting\\Hosting\\src\\Microsoft.AspNetCore.Hosting.csproj",
       "src\\Hosting\\Server.Abstractions\\src\\Microsoft.AspNetCore.Hosting.Server.Abstractions.csproj",
       "src\\Hosting\\Server.IntegrationTesting\\src\\Microsoft.AspNetCore.Server.IntegrationTesting.csproj",
+      "src\\Http\\Authentication.Abstractions\\src\\Microsoft.AspNetCore.Authentication.Abstractions.csproj",
+      "src\\Http\\Authentication.Core\\src\\Microsoft.AspNetCore.Authentication.Core.csproj",
       "src\\Http\\Features\\src\\Microsoft.Extensions.Features.csproj",
       "src\\Http\\Headers\\src\\Microsoft.Net.Http.Headers.csproj",
       "src\\Http\\Http.Abstractions\\src\\Microsoft.AspNetCore.Http.Abstractions.csproj",
       "src\\Http\\Http.Extensions\\src\\Microsoft.AspNetCore.Http.Extensions.csproj",
       "src\\Http\\Http.Features\\src\\Microsoft.AspNetCore.Http.Features.csproj",
       "src\\Http\\Http\\src\\Microsoft.AspNetCore.Http.csproj",
+      "src\\Http\\Metadata\\src\\Microsoft.AspNetCore.Metadata.csproj",
+      "src\\Http\\Routing.Abstractions\\src\\Microsoft.AspNetCore.Routing.Abstractions.csproj",
+      "src\\Http\\Routing\\src\\Microsoft.AspNetCore.Routing.csproj",
       "src\\Http\\WebUtilities\\src\\Microsoft.AspNetCore.WebUtilities.csproj",
+      "src\\Middleware\\Diagnostics.Abstractions\\src\\Microsoft.AspNetCore.Diagnostics.Abstractions.csproj",
+      "src\\Middleware\\Diagnostics\\src\\Microsoft.AspNetCore.Diagnostics.csproj",
+      "src\\Middleware\\HostFiltering\\src\\Microsoft.AspNetCore.HostFiltering.csproj",
+      "src\\Middleware\\HttpOverrides\\src\\Microsoft.AspNetCore.HttpOverrides.csproj",
       "src\\Middleware\\StaticFiles\\src\\Microsoft.AspNetCore.StaticFiles.csproj",
-      "src\\ObjectPool\\src\\Microsoft.Extensions.ObjectPool.csproj"
+      "src\\ObjectPool\\src\\Microsoft.Extensions.ObjectPool.csproj",
+      "src\\Security\\Authorization\\Core\\src\\Microsoft.AspNetCore.Authorization.csproj",
+      "src\\Servers\\Connections.Abstractions\\src\\Microsoft.AspNetCore.Connections.Abstractions.csproj",
+      "src\\Servers\\IIS\\IISIntegration\\src\\Microsoft.AspNetCore.Server.IISIntegration.csproj",
+      "src\\Servers\\IIS\\IIS\\src\\Microsoft.AspNetCore.Server.IIS.csproj",
+      "src\\Servers\\Kestrel\\Core\\src\\Microsoft.AspNetCore.Server.Kestrel.Core.csproj",
+      "src\\Servers\\Kestrel\\Kestrel\\src\\Microsoft.AspNetCore.Server.Kestrel.csproj",
+      "src\\Servers\\Kestrel\\Transport.Sockets\\src\\Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.csproj"
     ]
   }
 }

src/DefaultBuilder/src/WebApplicationBuilder.cs

@@ -177,9 +177,6 @@ private void ConfigureWebHost(IWebHostBuilder genericWebHostBuilder)
         {
             _hostBuilder.ConfigureHostConfiguration(builder =>
             {
-                // TODO: Use a ChainedConfigurationSource instead.
-                // See EnvironmentSpecificLoggingConfigurationSectionPassedToLoggerByDefault in WebApplicationFuncationalTests.
-
                 // All the sources in builder.Sources should be in Configuration.Sources
                 // already thanks to the BootstrapHostBuilder.
                 builder.Sources.Clear();
@@ -189,10 +186,7 @@ private void ConfigureWebHost(IWebHostBuilder genericWebHostBuilder)
                     builder.Properties[key] = value;
                 }
 
-                foreach (var s in ((IConfigurationBuilder)Configuration).Sources)
-                {
-                    builder.Sources.Add(s);
-                }
+                builder.AddConfiguration(Configuration, shouldDisposeConfiguration: true);
             });
 
             genericWebHostBuilder.ConfigureServices((context, services) =>

src/DefaultBuilder/test/Microsoft.AspNetCore.Tests/WebApplicationTests.cs

@@ -227,7 +227,7 @@ public async Task WebApplicationConfiguration_HostFilterOptionsAreReloadable()
             var changed = new TaskCompletionSource<int>(TaskCreationOptions.RunContinuationsAsynchronously);
             monitor.OnChange(newOptions =>
             {
-                changed.SetResult(0);
+                changed.TrySetResult(0);
             });
 
             config["AllowedHosts"] = "NewHost";