Public Register() + new Configure()

src/StructureMap.Microsoft.DependencyInjection/ContainerExtensions.cs

@@ -63,21 +63,19 @@ public static void Populate(this ConfigurationExpression config, IEnumerable<Ser
             ((Registry) config).Populate(descriptors, checkDuplicateCalls);
         }
 
-        /// <summary>
-        /// Populates the registry using the specified service descriptors.
-        /// </summary>
-        /// <remarks>
-        /// This method should only be called once per container.
-        /// </remarks>
-        /// <param name="registry">The registry.</param>
-        /// <param name="descriptors">The service descriptors.</param>
+        /// <inheritdoc cref="Populate(Registry, IEnumerable{ServiceDescriptor}, bool)"/>
         public static void Populate(this Registry registry, IEnumerable<ServiceDescriptor> descriptors)
         {
             registry.Populate(descriptors, checkDuplicateCalls: false);
         }
 
         /// <summary>
-        /// Populates the registry using the specified service descriptors.
+        /// Populates the registry using the specified service descriptors, plus:
+        /// <list type="bullet">
+        ///   <item><see cref="AspNetConstructorSelector"/></item>
+        ///   <item><see cref="StructureMapServiceProvider"/> as per-container <see cref="IServiceProvider"/></item>
+        ///   <item><see cref="StructureMapServiceScopeFactory"/> as per-container <see cref="IServiceScopeFactory"/></item>
+        /// </list>
         /// </summary>
         /// <remarks>
         /// This method should only be called once per container.
@@ -116,7 +114,26 @@ private static void ThrowIfMarkerInterfaceIsRegistered(PluginGraph graph)
             }
         }
 
-        private static void Register(this IProfileRegistry registry, IEnumerable<ServiceDescriptor> descriptors)
+        /// <summary>
+        /// Configures <paramref name="registry"/> with <paramref name="configure"/>.
+        /// </summary>
+        /// <remarks>
+        /// Unlike <see cref="Populate(Registry, IEnumerable{ServiceDescriptor})"/>, this method may be be called more than once per container.
+        /// </remarks>
+        /// <param name="registry">The registry.</param>
+        /// <param name="configure">The service configurator.</param>
+        public static void Configure(this IProfileRegistry registry, Func<IServiceCollection, IServiceCollection> configure) =>
+            registry.Register(configure(new SimpleServiceCollection()));
+
+        /// <summary>
+        /// Registers the specified service descriptors.
+        /// </summary>
+        /// <remarks>
+        /// Unlike <see cref="Populate(Registry, IEnumerable{ServiceDescriptor})"/>, this method may be be called more than once per container.
+        /// </remarks>
+        /// <param name="registry">The registry.</param>
+        /// <param name="descriptors">The service descriptors.</param>
+        public static void Register(this IProfileRegistry registry, IEnumerable<ServiceDescriptor> descriptors)
         {
             foreach (var descriptor in descriptors)
             {
@@ -155,5 +172,11 @@ private static Expression<Func<IContext, object>> CreateFactory(this ServiceDesc
         }
 
         private interface IMarkerInterface { }
+
+        // We don't depend on the package that declares ServiceCollection,
+        // but even if we did this is slightly better because we don't need its IsReadOnly checks
+        private class SimpleServiceCollection : List<ServiceDescriptor>, IServiceCollection
+        {
+        }
     }
 }

src/StructureMap.Microsoft.DependencyInjection/ServiceCollectionExtensions.cs

@@ -1,4 +1,5 @@
-using Microsoft.Extensions.DependencyInjection;
+using System;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace StructureMap
 {
@@ -13,5 +14,13 @@ public static IServiceCollection AddStructureMap(this IServiceCollection service
         {
             return services.AddSingleton<IServiceProviderFactory<Registry>>(new StructureMapServiceProviderFactory(registry));
         }
+
+        /// <summary>
+        /// Configures <paramref name="services"/> with <paramref name="configure"/>.
+        /// </summary>
+        /// <param name="services">The service collection.</param>
+        /// <param name="configure">The service configurator.</param>
+        /// <returns>The result of <paramref name="configure"/>, which should be <paramref name="services"/>.</returns>
+        public static IServiceCollection Configure(this IServiceCollection services, Func<IServiceCollection, IServiceCollection> configure) => configure(services);
     }
 }

test/StructureMap.Microsoft.DependencyInjection.Tests/StructureMapContainerTests.cs

@@ -38,6 +38,29 @@ protected override IServiceProvider CreateServiceProvider(IServiceCollection ser
             return container.GetInstance<IServiceProvider>();
         }
 
+        [Fact]
+        public void ConfigureAndRegisterDoNotPreventPopulate()
+        {
+            var services = new ServiceCollection();
+            services.AddTransient<IFakeService, FakeService>();
+
+            var container = new Container();
+            container.Configure(config =>
+            {
+                config.Register(services);
+                config.Register(services);
+
+                config.Configure(ctx => ctx.AddScoped<IFakeScopedService, FakeService>());
+                config.Configure(ctx => ctx.AddSingleton<IFakeSingletonService, FakeService>());
+
+                config.Populate(services, checkDuplicateCalls: true);
+            });
+
+            Assert.NotNull(container.GetInstance<IFakeService>());
+            Assert.NotNull(container.GetInstance<IFakeSingletonService>());
+            Assert.NotNull(container.GetInstance<IFakeScopedService>());
+        }
+
         [Theory]
         [InlineData(true)]
         [InlineData(false)]