Make ServiceCollectionExtensions consistent

samples/ElmPageSample/Startup.cs

@@ -12,9 +12,7 @@ namespace ElmPageSample
     {
         public void ConfigureServices(IServiceCollection services)
         {
-            services.AddElm();
+            services.AddElm(elmOptions =>
-
-            services.ConfigureElm(elmOptions =>
             {
                 elmOptions.Filter = (loggerName, loglevel) => loglevel == LogLevel.Debug;
             });

src/Microsoft.AspNetCore.Diagnostics.Elm/ElmExtensions.cs

@@ -23,9 +23,8 @@ namespace Microsoft.AspNetCore.Builder
 
             // add the elm provider to the factory here so the logger can start capturing logs immediately
             var factory = app.ApplicationServices.GetRequiredService<ILoggerFactory>();
-            var store = app.ApplicationServices.GetRequiredService<ElmStore>();
+            var provider = app.ApplicationServices.GetRequiredService<ElmLoggerProvider>();
-            var options = app.ApplicationServices.GetService<IOptions<ElmOptions>>();
+            factory.AddProvider(provider);
-            factory.AddProvider(new ElmLoggerProvider(store, options?.Value ?? new ElmOptions()));
 
             return app.UseMiddleware<ElmCaptureMiddleware>();
         }

src/Microsoft.AspNetCore.Diagnostics.Elm/ElmLoggerProvider.cs

@@ -3,6 +3,7 @@
 
 using System;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.AspNetCore.Diagnostics.Elm
 {
@@ -11,7 +12,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Elm
         private readonly ElmStore _store;
         private readonly ElmOptions _options;
 
-        public ElmLoggerProvider(ElmStore store, ElmOptions options)
+        public ElmLoggerProvider(ElmStore store, IOptions<ElmOptions> options)
         {
             if (store == null)
             {
@@ -24,7 +25,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Elm
             }
 
             _store = store;
-            _options = options;
+            _options = options.Value;
         }
 
         public ILogger CreateLogger(string name)

src/Microsoft.AspNetCore.Diagnostics.Elm/ElmServiceCollectionExtensions.cs

@@ -3,45 +3,50 @@
 
 using System;
 using Microsoft.AspNetCore.Diagnostics.Elm;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 
 namespace Microsoft.Extensions.DependencyInjection
 {
+    /// <summary>
+    /// Extension methods for setting up Elm services in an <see cref="IServiceCollection" />.
+    /// </summary>
     public static class ElmServiceCollectionExtensions
     {
         /// <summary>
-        /// Registers an <see cref="ElmStore"/> and configures default <see cref="ElmOptions"/>.
+        /// Adds error logging middleware services to the specified <see cref="IServiceCollection" />.
         /// </summary>
-        public static IServiceCollection AddElm(this IServiceCollection services)
+        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
+        public static void AddElm(this IServiceCollection services)
         {
             if (services == null)
             {
                 throw new ArgumentNullException(nameof(services));
             }
-            
+
-            services.AddSingleton<ElmStore>();
+            services.AddOptions();
-            return services;
+            services.TryAddSingleton<ElmStore>();
+            services.TryAddSingleton<ElmLoggerProvider>();
         }
 
         /// <summary>
-        /// Configures a set of <see cref="ElmOptions"/> for the application.
+        /// Adds error logging middleware services to the specified <see cref="IServiceCollection" />.
         /// </summary>
-        /// <param name="services">The services available in the application.</param>
+        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
-        /// <param name="configureOptions">The <see cref="ElmOptions"/> which need to be configured.</param>
+        /// <param name="setupAction">An <see cref="Action{ElmOptions}"/> to configure the provided <see cref="ElmOptions"/>.</param>
-        public static void ConfigureElm(
+        public static void AddElm(this IServiceCollection services, Action<ElmOptions> setupAction)
-            this IServiceCollection services,
-            Action<ElmOptions> configureOptions)
         {
             if (services == null)
             {
                 throw new ArgumentNullException(nameof(services));
             }
 
-            if (configureOptions == null)
+            if (setupAction == null)
             {
-                throw new ArgumentNullException(nameof(configureOptions));
+                throw new ArgumentNullException(nameof(setupAction));
             }
 
-            services.Configure(configureOptions);
+            services.AddElm();
+            services.Configure(setupAction);
         }
     }
 }

src/Microsoft.AspNetCore.MiddlewareAnalysis/AnalysisServiceCollectionExtensions.cs

@@ -1,17 +1,31 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.MiddlewareAnalysis;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 
 namespace Microsoft.Extensions.DependencyInjection
 {
+    /// <summary>
+    /// Extension methods for setting up diagnostic services in an <see cref="IServiceCollection" />.
+    /// </summary>
     public static class AnalysisServiceCollectionExtensions
     {
+        /// <summary>
+        /// Adds diagnostic services to the specified <see cref="IServiceCollection" />.
+        /// </summary>
+        /// <param name="services">The <see cref="IServiceCollection" /> to add services to.</param>
         public static IServiceCollection AddMiddlewareAnalysis(this IServiceCollection services)
         {
-            // This should prevent AnalysisStartupFilter from being registered more than once.
+            if (services == null)
+            {
+                throw new ArgumentNullException(nameof(services));
+            }
+
+            // Prevent registering the same implementation of IStartupFilter (AnalysisStartupFilter) multiple times.
+            // But allow multiple registrations of different implementation types.
             services.TryAddEnumerable(ServiceDescriptor.Transient<IStartupFilter, AnalysisStartupFilter>());
             return services;
         }

test/Microsoft.AspNetCore.Diagnostics.Tests/ElmLoggerTest.cs

@@ -7,6 +7,7 @@ using System.Linq;
 using System.Threading;
 using Microsoft.AspNetCore.Diagnostics.Elm;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Diagnostics.Tests
@@ -22,7 +23,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             // Arrange
             var store = new ElmStore();
             var options = new ElmOptions() { Filter = filter ?? _filter };
-            var provider = new ElmLoggerProvider(store, options);
+            var provider = new ElmLoggerProvider(store, Options.Create(options));
             var logger = (ElmLogger)provider.CreateLogger(name ?? _name);
 
             return new Tuple<ElmLogger, ElmStore>(logger, store);

test/Microsoft.AspNetCore.Diagnostics.Tests/ElmMiddlewareTest.cs

@@ -43,7 +43,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             optionsMock
                 .SetupGet(o => o.Value)
                 .Returns(new ElmOptions());
-            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object.Value));
+            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object));
 
             RequestDelegate next = _ =>
             {
@@ -80,7 +80,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             optionsMock
                 .SetupGet(o => o.Value)
                 .Returns(new ElmOptions());
-            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object.Value));
+            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object));
 
             RequestDelegate next = _ =>
             {
@@ -128,7 +128,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             optionsMock
                 .SetupGet(o => o.Value)
                 .Returns(new ElmOptions());
-            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object.Value));
+            factory.AddProvider(new ElmLoggerProvider(elmStore, optionsMock.Object));
 
             RequestDelegate next = _ =>
             {
@@ -230,7 +230,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             // Arrange
             var context = new DefaultHttpContext();
             var loggerFactory = new LoggerFactory();
-            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), new ElmOptions()));
+            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), Options.Create(new ElmOptions())));
 
             // Act & Assert
             var errorPageMiddleware = new ElmCaptureMiddleware((innerContext) =>
@@ -256,7 +256,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             };
             context.Features.Set<IHttpRequestIdentifierFeature>(requestIdentifierFeature);
             var loggerFactory = new LoggerFactory();
-            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), new ElmOptions()));
+            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), Options.Create(new ElmOptions())));
 
             var errorPageMiddleware = new ElmCaptureMiddleware((innerContext) =>
             {
@@ -278,7 +278,7 @@ namespace Microsoft.AspNetCore.Diagnostics.Tests
             var requestIdentifierFeature = new HttpRequestIdentifierFeature() { TraceIdentifier = requestId };
             context.Features.Set<IHttpRequestIdentifierFeature>(requestIdentifierFeature);
             var loggerFactory = new LoggerFactory();
-            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), new ElmOptions()));
+            loggerFactory.AddProvider(new ElmLoggerProvider(new ElmStore(), Options.Create(new ElmOptions())));
 
             var errorPageMiddleware = new ElmCaptureMiddleware((innerContext) =>
             {