Add missing TimeProvider registration (#53946)

Author: Prologh

src/Identity/Core/src/IdentityBuilderExtensions.cs

@@ -106,12 +106,14 @@ public static IdentityBuilder AddApiEndpoints(this IdentityBuilder builder)
     // Set TimeProvider from DI on all options instances, if not already set by tests.
     private sealed class PostConfigureSecurityStampValidatorOptions : IPostConfigureOptions<SecurityStampValidatorOptions>
     {
-        public PostConfigureSecurityStampValidatorOptions(TimeProvider timeProvider)
+        public PostConfigureSecurityStampValidatorOptions(TimeProvider? timeProvider = null)
         {
+            // We could assign this to "timeProvider ?? TimeProvider.System", but
+            // SecurityStampValidator already has system clock fallback logic.
             TimeProvider = timeProvider;
         }
 
-        private TimeProvider TimeProvider { get; }
+        private TimeProvider? TimeProvider { get; }
 
         public void PostConfigure(string? name, SecurityStampValidatorOptions options)
         {

src/Identity/Core/src/IdentityServiceCollectionExtensions.cs

@@ -171,12 +171,14 @@ public static IServiceCollection ConfigureExternalCookie(this IServiceCollection
 
     private sealed class PostConfigureSecurityStampValidatorOptions : IPostConfigureOptions<SecurityStampValidatorOptions>
     {
-        public PostConfigureSecurityStampValidatorOptions(TimeProvider timeProvider)
+        public PostConfigureSecurityStampValidatorOptions(TimeProvider? timeProvider = null)
         {
+            // We could assign this to "timeProvider ?? TimeProvider.System", but
+            // SecurityStampValidator already has system clock fallback logic.
             TimeProvider = timeProvider;
         }
 
-        private TimeProvider TimeProvider { get; }
+        private TimeProvider? TimeProvider { get; }
 
         public void PostConfigure(string? name, SecurityStampValidatorOptions options)
         {

src/Identity/test/Identity.Test/IdentityBuilderTest.cs

@@ -196,6 +196,45 @@ public void EnsureDefaultServices()
         Assert.IsType<UserManager<PocoUser>>(provider.GetRequiredService<UserManager<PocoUser>>());
     }
 
+    [Fact]
+    public void EnsureDefaultSignInManagerDependenciesForIdentity()
+    {
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build());
+        services.AddLogging()
+            .AddIdentity<PocoUser, PocoRole>()
+            .AddUserStore<NoopUserStore>()
+            .AddRoleStore<NoopRoleStore>()
+            .AddSignInManager<MySignInManager>();
+
+        var provider = services.BuildServiceProvider();
+
+        Assert.IsType<MySignInManager>(provider.GetRequiredService<SignInManager<PocoUser>>());
+        Assert.IsType<SecurityStampValidator<PocoUser>>(provider.GetRequiredService<ISecurityStampValidator>());
+        Assert.IsType<TwoFactorSecurityStampValidator<PocoUser>>(provider.GetRequiredService<ITwoFactorSecurityStampValidator>());
+        Assert.NotNull(provider.GetService<IOptions<SecurityStampValidatorOptions>>());
+    }
+
+    [Fact]
+    public void EnsureDefaultSignInManagerDependenciesForIdentityCore()
+    {
+        var services = new ServiceCollection()
+            .AddSingleton<IConfiguration>(new ConfigurationBuilder().Build());
+        services.AddLogging()
+            .AddIdentityCore<PocoUser>()
+            .AddRoles<PocoRole>()
+            .AddUserStore<NoopUserStore>()
+            .AddRoleStore<NoopRoleStore>()
+            .AddSignInManager<MySignInManager>();
+
+        var provider = services.BuildServiceProvider();
+
+        Assert.IsType<MySignInManager>(provider.GetRequiredService<SignInManager<PocoUser>>());
+        Assert.IsType<SecurityStampValidator<PocoUser>>(provider.GetRequiredService<ISecurityStampValidator>());
+        Assert.IsType<TwoFactorSecurityStampValidator<PocoUser>>(provider.GetRequiredService<ITwoFactorSecurityStampValidator>());
+        Assert.NotNull(provider.GetService<IOptions<SecurityStampValidatorOptions>>());
+    }
+
     [Fact]
     public void EnsureDefaultTokenProviders()
     {