Changes for error handling in Authentication

src/Microsoft.AspNet.Http.Abstractions/Authentication/AuthenticationManager.cs

@@ -11,6 +11,11 @@ namespace Microsoft.AspNet.Http.Authentication
 {
     public abstract class AuthenticationManager
     {
+        /// <summary>
+        /// Constant used to represent the automatic scheme
+        /// </summary>
+        public const string AutomaticScheme = "Automatic";
+
         public abstract IEnumerable<AuthenticationDescription> GetAuthenticationSchemes();
 
         public abstract Task AuthenticateAsync(AuthenticateContext context);
@@ -34,14 +39,14 @@ namespace Microsoft.AspNet.Http.Authentication
 
         public virtual Task ChallengeAsync(AuthenticationProperties properties)
         {
-            return ChallengeAsync(authenticationScheme: string.Empty, properties: properties);
+            return ChallengeAsync(authenticationScheme: AutomaticScheme, properties: properties);
         }
 
         public virtual Task ChallengeAsync(string authenticationScheme)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             return ChallengeAsync(authenticationScheme: authenticationScheme, properties: null);
@@ -50,9 +55,9 @@ namespace Microsoft.AspNet.Http.Authentication
         // Leave it up to authentication handler to do the right thing for the challenge
         public virtual Task ChallengeAsync(string authenticationScheme, AuthenticationProperties properties)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             return ChallengeAsync(authenticationScheme, properties, ChallengeBehavior.Automatic);
@@ -60,9 +65,9 @@ namespace Microsoft.AspNet.Http.Authentication
 
         public virtual Task SignInAsync(string authenticationScheme, ClaimsPrincipal principal)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             if (principal == null)

src/Microsoft.AspNet.Http.Features/Authentication/AuthenticateContext.cs

@@ -11,9 +11,9 @@ namespace Microsoft.AspNet.Http.Features.Authentication
     {
         public AuthenticateContext(string authenticationScheme)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             AuthenticationScheme = authenticationScheme;
@@ -29,6 +29,8 @@ namespace Microsoft.AspNet.Http.Features.Authentication
 
         public IDictionary<string, object> Description { get; private set; }
 
+        public Exception Error { get; private set; }
+
         public virtual void Authenticated(ClaimsPrincipal principal, IDictionary<string, string> properties, IDictionary<string, object> description)
         {
             Accepted = true;
@@ -41,5 +43,11 @@ namespace Microsoft.AspNet.Http.Features.Authentication
         {
             Accepted = true;
         }
+
+        public virtual void Failed(Exception error)
+        {
+            Error = error;
+            Accepted = true;
+        }
     }
 }

src/Microsoft.AspNet.Http.Features/Authentication/ChallengeContext.cs

@@ -15,9 +15,9 @@ namespace Microsoft.AspNet.Http.Features.Authentication
 
         public ChallengeContext(string authenticationScheme, IDictionary<string, string> properties, ChallengeBehavior behavior)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             AuthenticationScheme = authenticationScheme;

src/Microsoft.AspNet.Http.Features/Authentication/SignInContext.cs

@@ -11,9 +11,9 @@ namespace Microsoft.AspNet.Http.Features.Authentication
     {
         public SignInContext(string authenticationScheme, ClaimsPrincipal principal, IDictionary<string, string> properties)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             if (principal == null)

src/Microsoft.AspNet.Http.Features/Authentication/SignOutContext.cs

@@ -10,9 +10,9 @@ namespace Microsoft.AspNet.Http.Features.Authentication
     {
         public SignOutContext(string authenticationScheme, IDictionary<string, string> properties)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             AuthenticationScheme = authenticationScheme;

src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs

@@ -54,7 +54,6 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
             }
 
             var handler = HttpAuthenticationFeature.Handler;
-
             if (handler != null)
             {
                 await handler.AuthenticateAsync(context);
@@ -62,15 +61,15 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
 
             if (!context.Accepted)
             {
-                throw new InvalidOperationException($"The following authentication scheme was not accepted: {context.AuthenticationScheme}");
+                throw new InvalidOperationException($"No authentication handler is configured to authenticate for the scheme: {context.AuthenticationScheme}");
             }
         }
 
         public override async Task ChallengeAsync(string authenticationScheme, AuthenticationProperties properties, ChallengeBehavior behavior)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             var handler = HttpAuthenticationFeature.Handler;
@@ -83,15 +82,15 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
 
             if (!challengeContext.Accepted)
             {
-                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
+                throw new InvalidOperationException($"No authentication handler is configured to handle the scheme: {authenticationScheme}");
             }
         }
 
         public override async Task SignInAsync(string authenticationScheme, ClaimsPrincipal principal, AuthenticationProperties properties)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             if (principal == null)
@@ -109,15 +108,15 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
 
             if (!signInContext.Accepted)
             {
-                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
+                throw new InvalidOperationException($"No authentication handler is configured to handle the scheme: {authenticationScheme}");
             }
         }
 
         public override async Task SignOutAsync(string authenticationScheme, AuthenticationProperties properties)
         {
-            if (authenticationScheme == null)
+            if (string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new ArgumentNullException(nameof(authenticationScheme));
+                throw new ArgumentException(nameof(authenticationScheme));
             }
 
             var handler = HttpAuthenticationFeature.Handler;
@@ -130,7 +129,7 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
 
             if (!signOutContext.Accepted)
             {
-                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
+                throw new InvalidOperationException($"No authentication handler is configured to handle the scheme: {authenticationScheme}");
             }
         }
     }

test/Microsoft.AspNet.Http.Tests/Authentication/DefaultAuthenticationManagerTests.cs

@@ -12,7 +12,7 @@ using Xunit;
 
 namespace Microsoft.AspNet.Http.Authentication.Internal
 {
-    public class AuthenticationManagerTests
+    public class DefaultAuthenticationManagerTests
     {
 
         [Fact]
@@ -23,7 +23,7 @@ namespace Microsoft.AspNet.Http.Authentication.Internal
         }
 
         [Theory]
-        [InlineData("")]
+        [InlineData("Automatic")]
         [InlineData("Foo")]
         public async Task ChallengeWithNoAuthMiddlewareMayThrow(string scheme)
         {