Mark WebHostBuilder class as obsolete

src/DataProtection/DataProtection/test/Microsoft.AspNetCore.DataProtection.Tests/HostingTests.cs

@@ -25,6 +25,7 @@ public async Task WebhostLoadsKeyRingBeforeServerStarts()
             .Returns(Mock.Of<IKeyRing>())
             .Callback(() => tcs.TrySetResult());
 
+#pragma warning disable CS0618 // Type or member is obsolete
         var builder = new WebHostBuilder()
             .UseStartup<TestStartup>()
             .ConfigureServices(s =>
@@ -33,6 +34,7 @@ public async Task WebhostLoadsKeyRingBeforeServerStarts()
                 .Replace(ServiceDescriptor.Singleton(mockKeyRing.Object))
                 .AddSingleton<IServer>(
                     new FakeServer(onStart: () => tcs.TrySetException(new InvalidOperationException("Server was started before key ring was initialized")))));
+#pragma warning restore CS0618 // Type or member is obsolete
 
         using (var host = builder.Build())
         {

src/DefaultBuilder/src/WebHost.cs

@@ -154,7 +154,9 @@ public static IWebHostBuilder CreateDefaultBuilder() =>
     /// <returns>The initialized <see cref="IWebHostBuilder"/>.</returns>
     public static IWebHostBuilder CreateDefaultBuilder(string[] args)
     {
+#pragma warning disable CS0618 // Type or member is obsolete
         var builder = new WebHostBuilder();
+#pragma warning restore CS0618 // Type or member is obsolete
 
         if (string.IsNullOrEmpty(builder.GetSetting(WebHostDefaults.ContentRootKey)))
         {

src/Hosting/Hosting/src/WebHostBuilder.cs

@@ -20,6 +20,7 @@ namespace Microsoft.AspNetCore.Hosting;
 /// <summary>
 /// A builder for <see cref="IWebHost"/>
 /// </summary>
+[Obsolete("TODO: Add Obsolete message")]
 public class WebHostBuilder : IWebHostBuilder
 {
     private readonly HostingEnvironment _hostingEnvironment;

src/Hosting/Hosting/test/WebHostBuilderTests.cs

@@ -429,6 +429,7 @@ public void DoNotCaptureStartupErrorsByDefault(IWebHostBuilder builder)
     public void ServiceProviderDisposedOnBuildException()
     {
         var service = new DisposableService();
+#pragma warning disable CS0618 // Type or member is obsolete
         var hostBuilder = new WebHostBuilder()
             .UseServer(new TestServer())
             .ConfigureServices(services =>
@@ -437,6 +438,7 @@ public void ServiceProviderDisposedOnBuildException()
                 services.AddSingleton(sp => service);
             })
             .UseStartup<StartupWithResolvedDisposableThatThrows>();
+#pragma warning restore CS0618 // Type or member is obsolete
 
         Assert.Throws<InvalidOperationException>(() => hostBuilder.Build());
         Assert.True(service.Disposed);
@@ -1483,14 +1485,18 @@ private IWebHostBuilder CreateWebHostBuilder()
             .AddInMemoryCollection(vals);
         var config = builder.Build();
 
+#pragma warning disable CS0618 // Type or member is obsolete
         return new WebHostBuilder().UseConfiguration(config);
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
+#pragma warning disable CS0618 // Type or member is obsolete
     public static TheoryData<IWebHostBuilder> DefaultWebHostBuilders => new TheoryData<IWebHostBuilder>
         {
             new WebHostBuilder(),
             new GenericWebHostBuilderWrapper(new HostBuilder())
         };
+#pragma warning restore CS0618 // Type or member is obsolete
 
     public static TheoryData<IWebHostBuilder> DefaultWebHostBuildersWithConfig
     {
@@ -1506,10 +1512,12 @@ public static TheoryData<IWebHostBuilder> DefaultWebHostBuildersWithConfig
                 .AddInMemoryCollection(vals);
             var config = builder.Build();
 
+#pragma warning disable CS0618 // Type or member is obsolete
             return new TheoryData<IWebHostBuilder> {
                     new WebHostBuilder().UseConfiguration(config),
                     new GenericWebHostBuilderWrapper(new HostBuilder()).UseConfiguration(config)
                 };
+#pragma warning restore CS0618 // Type or member is obsolete
         }
     }
 
@@ -1783,3 +1791,4 @@ public void Dispose()
         public void AddProvider(ILoggerProvider provider) { }
     }
 }
+//#pragma warning restore CS0618 // Type or member is obsolete

src/Hosting/Hosting/test/WebHostTests.cs

@@ -1103,7 +1103,9 @@ private IWebHost CreateHost(RequestDelegate requestDelegate)
 
     private IWebHostBuilder CreateBuilder(IConfiguration config = null)
     {
+#pragma warning disable CS0618 // Type or member is obsolete
         return new WebHostBuilder().UseConfiguration(config ?? new ConfigurationBuilder().Build()).UseStartup("Microsoft.AspNetCore.Hosting.Tests");
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
     private static bool[] RegisterCallbacksThatThrow(IServiceCollection services)

src/Hosting/TestHost/test/ClientHandlerTests.cs

@@ -11,6 +11,7 @@
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.InternalTesting;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Microsoft.Net.Http.Headers;
 
@@ -691,19 +692,27 @@ public async Task ClientHandlerCreateContextWithDefaultRequestParameters()
     {
         // This logger will attempt to access information from HttpRequest once the HttpContext is created
         var logger = new VerifierLogger();
-        var builder = new WebHostBuilder()
-            .ConfigureServices(services =>
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
             {
-                services.AddSingleton<ILogger<IWebHost>>(logger);
+                webHostBuilder
+                    .UseTestServer()
+                    .ConfigureServices(services =>
+                    {
+                        services.AddSingleton<ILogger<IWebHost>>(logger);
+                    })
+                    .Configure(app =>
+                    {
+                        app.Run(context =>
+                        {
+                            return Task.FromResult(0);
+                        });
+                    });
             })
-            .Configure(app =>
-            {
-                app.Run(context =>
-                {
-                    return Task.FromResult(0);
-                });
-            });
-        var server = new TestServer(builder);
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
 
         // The HttpContext will be created and the logger will make sure that the HttpRequest exists and contains reasonable values
         var result = await server.CreateClient().GetStringAsync("/");

src/Hosting/TestHost/test/HttpContextBuilderTests.cs

@@ -1,13 +1,16 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+#pragma warning disable CS0618 // Type or member is obsolete
+
 using System.Text;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.InternalTesting;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.TestHost;
@@ -17,8 +20,18 @@ public class HttpContextBuilderTests
     [Fact]
     public async Task ExpectedValuesAreAvailable()
     {
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webBuilder =>
+            {
+                webBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
+
         server.BaseAddress = new Uri("https://example.com/A/Path/");
         var context = await server.SendAsync(c =>
         {
@@ -48,8 +61,18 @@ public async Task ExpectedValuesAreAvailable()
     public async Task UserAgentHeaderWorks()
     {
         var userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0";
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webBuilder =>
+            {
+                webBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
+
         server.BaseAddress = new Uri("https://example.com/");
         var context = await server.SendAsync(c =>
         {
@@ -63,8 +86,18 @@ public async Task UserAgentHeaderWorks()
     [Fact]
     public async Task SingleSlashNotMovedToPathBase()
     {
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webBuilder =>
+            {
+                webBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
+
         var context = await server.SendAsync(c =>
         {
             c.Request.Path = "/";
@@ -77,15 +110,25 @@ public async Task SingleSlashNotMovedToPathBase()
     [Fact]
     public async Task MiddlewareOnlySetsHeaders()
     {
-        var builder = new WebHostBuilder().Configure(app =>
-        {
-            app.Run(c =>
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webBuilder =>
             {
-                c.Response.Headers["TestHeader"] = "TestValue";
-                return Task.FromResult(0);
-            });
-        });
-        var server = new TestServer(builder);
+                webBuilder
+                    .UseTestServer()
+                    .Configure(app =>
+                    {
+                        app.Run(c =>
+                        {
+                            c.Response.Headers["TestHeader"] = "TestValue";
+                            return Task.FromResult(0);
+                        });
+                    });
+            })
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
+
         var context = await server.SendAsync(c => { });
 
         Assert.Equal("TestValue", context.Response.Headers["TestHeader"]);
@@ -306,19 +349,27 @@ public async Task ClientHandlerCreateContextWithDefaultRequestParameters()
     {
         // This logger will attempt to access information from HttpRequest once the HttpContext is created
         var logger = new VerifierLogger();
-        var builder = new WebHostBuilder()
-            .ConfigureServices(services =>
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webBuilder =>
             {
-                services.AddSingleton<ILogger<IWebHost>>(logger);
+                webBuilder
+                    .UseTestServer()
+                    .ConfigureServices(services =>
+                    {
+                        services.AddSingleton<ILogger<IWebHost>>(logger);
+                    })
+                    .Configure(app =>
+                    {
+                        app.Run(context =>
+                        {
+                            return Task.FromResult(0);
+                        });
+                    });
             })
-            .Configure(app =>
-            {
-                app.Run(context =>
-                {
-                    return Task.FromResult(0);
-                });
-            });
-        var server = new TestServer(builder);
+            .Build();
+        var server = host.GetTestServer();
+
+        await host.StartAsync();
 
         // The HttpContext will be created and the logger will make sure that the HttpRequest exists and contains reasonable values
         var ctx = await server.SendAsync(c => { });

src/Hosting/TestHost/test/RequestBuilderTests.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 
 namespace Microsoft.AspNetCore.TestHost;
 
@@ -10,8 +11,15 @@ public class RequestBuilderTests
     [Fact]
     public void AddRequestHeader()
     {
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
         server.CreateRequest("/")
             .AddHeader("Host", "MyHost:90")
             .And(request =>
@@ -23,8 +31,15 @@ public void AddRequestHeader()
     [Fact]
     public void AddContentHeaders()
     {
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
         server.CreateRequest("/")
             .AddHeader("Content-Type", "Test/Value")
             .And(request =>
@@ -38,8 +53,15 @@ public void AddContentHeaders()
     public void TestServer_PropertyShouldHoldTestServerInstance()
     {
         // Arrange
-        var builder = new WebHostBuilder().Configure(app => { });
-        var server = new TestServer(builder);
+        using var host = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseTestServer()
+                    .Configure(app => { });
+            })
+            .Build();
+        var server = host.GetTestServer();
 
         // Act
         var requestBuilder = server.CreateRequest("/");