Updates to AddManager behavior

src/Microsoft.AspNet.Identity/IdentityBuilder.cs

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Reflection;
 using Microsoft.Framework.DependencyInjection;
 
 namespace Microsoft.AspNet.Identity
@@ -159,7 +160,15 @@ namespace Microsoft.AspNet.Identity
         /// <returns>The <see cref="IdentityBuilder"/>.</returns>
         public virtual IdentityBuilder AddUserManager<TUserManager>() where TUserManager : class
         {
-            return AddScoped(typeof(UserManager<>).MakeGenericType(UserType), typeof(TUserManager));
+            var userManagerType = typeof(UserManager<>).MakeGenericType(UserType);
+            var customType = typeof(TUserManager);
+            if (userManagerType == customType ||
+                !userManagerType.GetTypeInfo().IsAssignableFrom(customType.GetTypeInfo()))
+            {
+                throw new InvalidOperationException(Resources.FormatInvalidManagerType(customType.Name, "UserManager", UserType.Name));
+            }
+            Services.AddScoped(customType, services => services.GetRequiredService(userManagerType));
+            return AddScoped(userManagerType, customType);
         }
 
         /// <summary>
@@ -169,7 +178,15 @@ namespace Microsoft.AspNet.Identity
         /// <returns>The <see cref="IdentityBuilder"/>.</returns>
         public virtual IdentityBuilder AddRoleManager<TRoleManager>() where TRoleManager : class
         {
-            return AddScoped(typeof(RoleManager<>).MakeGenericType(RoleType), typeof(TRoleManager));
+            var managerType = typeof(RoleManager<>).MakeGenericType(RoleType);
+            var customType = typeof(TRoleManager);
+            if (managerType == customType ||
+                !managerType.GetTypeInfo().IsAssignableFrom(customType.GetTypeInfo()))
+            {
+                throw new InvalidOperationException(Resources.FormatInvalidManagerType(customType.Name, "RoleManager", RoleType.Name));
+            }
+            Services.AddScoped(typeof(TRoleManager), services => services.GetRequiredService(managerType));
+            return AddScoped(managerType, typeof(TRoleManager));
         }
     }
 }

src/Microsoft.AspNet.Identity/Properties/Resources.Designer.cs

@@ -122,6 +122,22 @@ namespace Microsoft.AspNet.Identity
             return string.Format(CultureInfo.CurrentCulture, GetString("InvalidEmail"), p0);
         }
 
+        /// <summary>
+        /// Type {0} must be derived from {1}&lt;{2}&gt;.
+        /// </summary>
+        internal static string InvalidManagerType
+        {
+            get { return GetString("InvalidManagerType"); }
+        }
+
+        /// <summary>
+        /// Type {0} must be derived from {1}&lt;{2}&gt;.
+        /// </summary>
+        internal static string FormatInvalidManagerType(object p0, object p1, object p2)
+        {
+            return string.Format(CultureInfo.CurrentCulture, GetString("InvalidManagerType"), p0, p1, p2);
+        }
+
         /// <summary>
         /// The provided PasswordHasherCompatibilityMode is invalid.
         /// </summary>

src/Microsoft.AspNet.Identity/Resources.resx

@@ -145,6 +145,10 @@
     <value>Email '{0}' is invalid.</value>
     <comment>Invalid email</comment>
   </data>
+  <data name="InvalidManagerType" xml:space="preserve">
+    <value>Type {0} must be derived from {1}&lt;{2}&gt;.</value>
+    <comment>Error when the manager type is not derived correctly</comment>
+  </data>
   <data name="InvalidPasswordHasherCompatibilityMode" xml:space="preserve">
     <value>The provided PasswordHasherCompatibilityMode is invalid.</value>
     <comment>Error when the password hasher doesn't understand the format it's being asked to produce.</comment>

test/Microsoft.AspNet.Identity.Test/UserManagerTest.cs

@@ -31,6 +31,46 @@ namespace Microsoft.AspNet.Identity.Test
             Assert.NotNull(manager.Options);
         }
 
+        [Fact]
+        public void AddUserManagerWithCustomManagerReturnsSameInstance()
+        {
+            var services = new ServiceCollection()
+                    .AddTransient<IUserStore<TestUser>, NoopUserStore>()
+                    .AddSingleton<IHttpContextAccessor, HttpContextAccessor>()
+                    .AddLogging();
+            services.AddIdentity<TestUser, TestRole>()
+                .AddUserManager<CustomUserManager>()
+                .AddRoleManager<CustomRoleManager>();
+            var provider = services.BuildServiceProvider();
+            Assert.Same(provider.GetRequiredService<UserManager<TestUser>>(), 
+                provider.GetRequiredService<CustomUserManager>());
+            Assert.Same(provider.GetRequiredService<RoleManager<TestRole>>(),
+                provider.GetRequiredService<CustomRoleManager>());
+        }
+
+        [Fact]
+        public void AddManagerWithWrongTypesThrows()
+        {
+            var services = new ServiceCollection();
+            var builder = services.AddIdentity<TestUser, TestRole>();
+            Assert.Throws<InvalidOperationException>(() => builder.AddUserManager<UserManager<TestUser>>());
+            Assert.Throws<InvalidOperationException>(() => builder.AddRoleManager<RoleManager<TestRole>>());
+            Assert.Throws<InvalidOperationException>(() => builder.AddUserManager<object>());
+            Assert.Throws<InvalidOperationException>(() => builder.AddRoleManager<object>());
+        }
+
+        public class CustomUserManager : UserManager<TestUser>
+        {
+            public CustomUserManager() : base(new Mock<IUserStore<TestUser>>().Object, null, null, null, null, null, null, null, null, null)
+            { }
+        }
+
+        public class CustomRoleManager : RoleManager<TestRole>
+        {
+            public CustomRoleManager() : base(new Mock<IRoleStore<TestRole>>().Object, null, null, null, null, null)
+            { }
+        }
+
         [Fact]
         public async Task CreateCallsStore()
         {