Add AddHttpClientDefaults

src/libraries/Microsoft.Extensions.Http/ref/Microsoft.Extensions.Http.cs

@@ -12,12 +12,15 @@ public static partial class HttpClientBuilderExtensions
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddTypedClient<TClient>(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Func<System.Net.Http.HttpClient, System.IServiceProvider, TClient> factory) where TClient : class { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddTypedClient<TClient>(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Func<System.Net.Http.HttpClient, TClient> factory) where TClient : class { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddTypedClient<TClient, [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembersAttribute(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)] TImplementation>(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder) where TClient : class where TImplementation : class, TClient { throw null; }
+        public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigureAdditionalHttpMessageHandlers(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Action<System.Collections.Generic.IList<System.Net.Http.DelegatingHandler>, System.IServiceProvider> configureAdditionalHandlers) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigureHttpClient(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Action<System.IServiceProvider, System.Net.Http.HttpClient> configureClient) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigureHttpClient(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Action<System.Net.Http.HttpClient> configureClient) { throw null; }
+        [System.Obsolete("This method has been deprecated. Use ConfigurePrimaryHttpMessageHandler or ConfigureAdditionalHttpMessageHandlers instead.")]
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigureHttpMessageHandlerBuilder(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Action<Microsoft.Extensions.Http.HttpMessageHandlerBuilder> configureBuilder) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigurePrimaryHttpMessageHandler(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Func<System.IServiceProvider, System.Net.Http.HttpMessageHandler> configureHandler) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigurePrimaryHttpMessageHandler(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Func<System.Net.Http.HttpMessageHandler> configureHandler) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigurePrimaryHttpMessageHandler<THandler>(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder) where THandler : System.Net.Http.HttpMessageHandler { throw null; }
+        public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder ConfigurePrimaryHttpMessageHandler(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Action<System.Net.Http.HttpMessageHandler, System.IServiceProvider> configureHandler) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder RedactLoggedHeaders(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Collections.Generic.IEnumerable<string> redactedLoggedHeaderNames) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder RedactLoggedHeaders(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.Func<string, bool> shouldRedactHeaderValue) { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder SetHandlerLifetime(this Microsoft.Extensions.DependencyInjection.IHttpClientBuilder builder, System.TimeSpan handlerLifetime) { throw null; }
@@ -44,6 +47,7 @@ public static partial class HttpClientFactoryServiceCollectionExtensions
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddHttpClient<TClient, [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembersAttribute(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)] TImplementation>(this Microsoft.Extensions.DependencyInjection.IServiceCollection services, string name, System.Action<System.Net.Http.HttpClient> configureClient) where TClient : class where TImplementation : class, TClient { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddHttpClient<TClient, TImplementation>(this Microsoft.Extensions.DependencyInjection.IServiceCollection services, string name, System.Func<System.Net.Http.HttpClient, System.IServiceProvider, TImplementation> factory) where TClient : class where TImplementation : class, TClient { throw null; }
         public static Microsoft.Extensions.DependencyInjection.IHttpClientBuilder AddHttpClient<TClient, TImplementation>(this Microsoft.Extensions.DependencyInjection.IServiceCollection services, string name, System.Func<System.Net.Http.HttpClient, TImplementation> factory) where TClient : class where TImplementation : class, TClient { throw null; }
+        public static Microsoft.Extensions.DependencyInjection.IServiceCollection ConfigureHttpClientDefaults(Microsoft.Extensions.DependencyInjection.IServiceCollection services, System.Action<Microsoft.Extensions.DependencyInjection.IHttpClientBuilder> configure) { throw null; }
     }
     public partial interface IHttpClientBuilder
     {

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/DefaultHttpClientBuilder.cs

@@ -1,14 +1,21 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Diagnostics;
+using System.Linq;
+
 namespace Microsoft.Extensions.DependencyInjection
 {
     internal sealed class DefaultHttpClientBuilder : IHttpClientBuilder
     {
         public DefaultHttpClientBuilder(IServiceCollection services, string name)
         {
-            Services = services;
-            Name = name;
+            // The tracker references a descriptor. It marks the position of where default services are added to the collection.
+            var tracker = (DefaultHttpClientConfigurationTracker?)services.Single(sd => sd.ServiceType == typeof(DefaultHttpClientConfigurationTracker)).ImplementationInstance;
+            Debug.Assert(tracker != null);
+
+            Services = new DefaultHttpClientBuilderServiceCollection(services, name == null, tracker);
+            Name = name!;
         }
 
         public string Name { get; }

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/DefaultHttpClientBuilderServiceCollection.cs

@@ -0,0 +1,76 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.Extensions.Http;
+using Microsoft.Extensions.Options;
+
+namespace Microsoft.Extensions.DependencyInjection
+{
+    internal sealed class DefaultHttpClientBuilderServiceCollection : IServiceCollection
+    {
+        private readonly IServiceCollection _services;
+        private readonly bool _isDefault;
+        private readonly DefaultHttpClientConfigurationTracker _tracker;
+
+        public DefaultHttpClientBuilderServiceCollection(IServiceCollection services, bool isDefault, DefaultHttpClientConfigurationTracker tracker)
+        {
+            _services = services;
+            _isDefault = isDefault;
+            _tracker = tracker;
+        }
+
+        public void Add(ServiceDescriptor item)
+        {
+            if (item.ServiceType != typeof(IConfigureOptions<HttpClientFactoryOptions>))
+            {
+                _services.Add(item);
+                return;
+            }
+
+            if (_isDefault)
+            {
+                // Insert IConfigureOptions<HttpClientFactoryOptions> services into the collection before named config descriptors.
+                // This ensures they run and apply configuration first. Configuration for named clients run afterwards.
+                if (_tracker.InsertDefaultsAfterDescriptor != null &&
+                    _services.IndexOf(_tracker.InsertDefaultsAfterDescriptor) is var index && index != -1)
+                {
+                    index++;
+                    _services.Insert(index, item);
+                }
+                else
+                {
+                    _services.Add(item);
+                }
+
+                _tracker.InsertDefaultsAfterDescriptor = item;
+            }
+            else
+            {
+                // Track the location of where the first named config descriptor was added.
+                _tracker.InsertDefaultsAfterDescriptor ??= _services.Last();
+
+                _services.Add(item);
+            }
+        }
+
+        public ServiceDescriptor this[int index]
+        {
+            get => _services[index];
+            set => _services[index] = value;
+        }
+        public int Count => _services.Count;
+        public bool IsReadOnly => _services.IsReadOnly;
+        public void Clear() => _services.Clear();
+        public bool Contains(ServiceDescriptor item) => _services.Contains(item);
+        public void CopyTo(ServiceDescriptor[] array, int arrayIndex) => _services.CopyTo(array, arrayIndex);
+        public IEnumerator<ServiceDescriptor> GetEnumerator() => _services.GetEnumerator();
+        public int IndexOf(ServiceDescriptor item) => _services.IndexOf(item);
+        public void Insert(int index, ServiceDescriptor item) => _services.Insert(index, item);
+        public bool Remove(ServiceDescriptor item) => _services.Remove(item);
+        public void RemoveAt(int index) => _services.RemoveAt(index);
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+    }
+}

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/DefaultHttpClientConfigurationTracker.cs

@@ -0,0 +1,10 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.Extensions.DependencyInjection
+{
+    internal sealed class DefaultHttpClientConfigurationTracker
+    {
+        public ServiceDescriptor? InsertDefaultsAfterDescriptor { get; set; }
+    }
+}

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/HttpClientBuilderExtensions.cs

@@ -220,13 +220,40 @@ public static IHttpClientBuilder ConfigurePrimaryHttpMessageHandler<THandler>(th
             return builder;
         }
 
+        /// <summary>
+        /// Adds a delegate that will be used to configure the primary <see cref="HttpMessageHandler"/> for a
+        /// named <see cref="HttpClient"/>.
+        /// </summary>
+        /// <param name="builder">The <see cref="IHttpClientBuilder"/>.</param>
+        /// <param name="configureHandler">A delegate that is used to configure a previously set or default primary <see cref="HttpMessageHandler"/>.</param>
+        /// <returns>An <see cref="IHttpClientBuilder"/> that can be used to configure the client.</returns>
+        /// <remarks>
+        /// <para>
+        /// The <see cref="IServiceProvider"/> argument provided to <paramref name="configureHandler"/> will be
+        /// a reference to a scoped service provider that shares the lifetime of the handler being constructed.
+        /// </para>
+        /// </remarks>
+        public static IHttpClientBuilder ConfigurePrimaryHttpMessageHandler(this IHttpClientBuilder builder, Action<HttpMessageHandler, IServiceProvider> configureHandler)
+        {
+            ThrowHelper.ThrowIfNull(builder);
+            ThrowHelper.ThrowIfNull(configureHandler);
+
+            builder.Services.Configure<HttpClientFactoryOptions>(builder.Name, options =>
+            {
+                options.HttpMessageHandlerBuilderActions.Add(b => configureHandler(b.PrimaryHandler, b.Services));
+            });
+
+            return builder;
+        }
+
         /// <summary>
         /// Adds a delegate that will be used to configure message handlers using <see cref="HttpMessageHandlerBuilder"/>
         /// for a named <see cref="HttpClient"/>.
         /// </summary>
         /// <param name="builder">The <see cref="IHttpClientBuilder"/>.</param>
         /// <param name="configureBuilder">A delegate that is used to configure an <see cref="HttpMessageHandlerBuilder"/>.</param>
         /// <returns>An <see cref="IHttpClientBuilder"/> that can be used to configure the client.</returns>
+        [Obsolete("This method has been deprecated. Use ConfigurePrimaryHttpMessageHandler or ConfigureAdditionalHttpMessageHandlers instead.")]
         public static IHttpClientBuilder ConfigureHttpMessageHandlerBuilder(this IHttpClientBuilder builder, Action<HttpMessageHandlerBuilder> configureBuilder)
         {
             ThrowHelper.ThrowIfNull(builder);
@@ -275,6 +302,11 @@ public static IHttpClientBuilder ConfigureHttpMessageHandlerBuilder(this IHttpCl
             this IHttpClientBuilder builder, bool validateSingleType)
             where TClient : class
         {
+            if (builder.Name is null)
+            {
+                throw new InvalidOperationException($"{nameof(HttpClientBuilderExtensions.AddTypedClient)} isn't supported with {nameof(HttpClientFactoryServiceCollectionExtensions.ConfigureHttpClientDefaults)}.");
+            }
+
             ReserveClient(builder, typeof(TClient), builder.Name, validateSingleType);
 
             builder.Services.AddTransient(s => AddTransientHelper<TClient>(s, builder));
@@ -531,6 +563,26 @@ public static IHttpClientBuilder SetHandlerLifetime(this IHttpClientBuilder buil
             return builder;
         }
 
+        /// <summary>
+        /// Adds a delegate that will be used to configure additional message handlers using <see cref="HttpMessageHandlerBuilder"/>
+        /// for a named <see cref="HttpClient"/>.
+        /// </summary>
+        /// <param name="builder">The <see cref="IHttpClientBuilder"/>.</param>
+        /// <param name="configureAdditionalHandlers">A delegate that is used to configure a collection of <see cref="DelegatingHandler"/>s.</param>
+        /// <returns>An <see cref="IHttpClientBuilder"/> that can be used to configure the client.</returns>
+        public static IHttpClientBuilder ConfigureAdditionalHttpMessageHandlers(this IHttpClientBuilder builder, Action<IList<DelegatingHandler>, IServiceProvider> configureAdditionalHandlers)
+        {
+            ThrowHelper.ThrowIfNull(builder);
+            ThrowHelper.ThrowIfNull(configureAdditionalHandlers);
+
+            builder.Services.Configure<HttpClientFactoryOptions>(builder.Name, options =>
+            {
+                options.HttpMessageHandlerBuilderActions.Add(b => configureAdditionalHandlers(b.AdditionalHandlers, b.Services));
+            });
+
+            return builder;
+        }
+
         // See comments on HttpClientMappingRegistry.
         private static void ReserveClient(IHttpClientBuilder builder, Type type, string name, bool validateSingleType)
         {

src/libraries/Microsoft.Extensions.Http/src/DependencyInjection/HttpClientFactoryServiceCollectionExtensions.cs

@@ -2,7 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Collections.Generic;
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using System.Net.Http;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Http;
@@ -50,6 +53,9 @@ public static IServiceCollection AddHttpClient(this IServiceCollection services)
             // because we access it by reaching into the service collection.
             services.TryAddSingleton(new HttpClientMappingRegistry());
 
+            // This is used to store configuration for the default builder.
+            services.TryAddSingleton(new DefaultHttpClientConfigurationTracker());
+
             // Register default client as HttpClient
             services.TryAddTransient(s =>
             {
@@ -59,6 +65,24 @@ public static IServiceCollection AddHttpClient(this IServiceCollection services)
             return services;
         }
 
+        /// <summary>
+        /// Adds a delegate that will be used to configure all <see cref="HttpClient"/> instances.
+        /// </summary>
+        /// <param name="services">The <see cref="IServiceCollection"/>.</param>
+        /// <param name="configure">A delegate that is used to configure an <see cref="IHttpClientBuilder"/>.</param>
+        /// <returns>The <see cref="IServiceCollection"/>.</returns>
+        public static IServiceCollection ConfigureHttpClientDefaults(this IServiceCollection services, Action<IHttpClientBuilder> configure)
+        {
+            ThrowHelper.ThrowIfNull(services);
+            ThrowHelper.ThrowIfNull(configure);
+
+            AddHttpClient(services);
+
+            configure(new DefaultHttpClientBuilder(services, name: null!));
+
+            return services;
+        }
+
         /// <summary>
         /// Adds the <see cref="IHttpClientFactory"/> and related services to the <see cref="IServiceCollection"/> and configures
         /// a named <see cref="HttpClient"/>.