ISystemOperations.AuthenticateAsync now returns AuthResponse.

src/Docker.DotNet/Endpoints/ISystemOperations.cs

@@ -18,7 +18,7 @@ public interface ISystemOperations
         /// 204 - No error.
         /// 500 - Server error.
         /// </remarks>
-        Task AuthenticateAsync(AuthConfig authConfig, CancellationToken cancellationToken = default(CancellationToken));
+        Task<AuthResponse> AuthenticateAsync(AuthConfig authConfig, CancellationToken cancellationToken = default(CancellationToken));
 
         /// <summary>
         /// Get version.

src/Docker.DotNet/Endpoints/SystemOperations.cs

@@ -16,15 +16,16 @@ internal SystemOperations(DockerClient client)
             this._client = client;
         }
 
-        public Task AuthenticateAsync(AuthConfig authConfig, CancellationToken cancellationToken = default(CancellationToken))
+        public async Task<AuthResponse> AuthenticateAsync(AuthConfig authConfig, CancellationToken cancellationToken = default(CancellationToken))
         {
             if (authConfig == null)
             {
                 throw new ArgumentNullException(nameof(authConfig));
             }
-            var data = new JsonRequestContent<AuthConfig>(authConfig, this._client.JsonSerializer);
-
-            return this._client.MakeRequestAsync(this._client.NoErrorHandlers, HttpMethod.Post, "auth", null, data, cancellationToken);
+            var data = new JsonRequestContent<AuthConfig>(authConfig, this._client.JsonSerializer);
+
+            var response = await this._client.MakeRequestAsync(this._client.NoErrorHandlers, HttpMethod.Post, "auth", null, data, cancellationToken).ConfigureAwait(false);
+            return this._client.JsonSerializer.DeserializeObject<AuthResponse>(response.Body);
         }
 
         public async Task<VersionResponse> GetVersionAsync(CancellationToken cancellationToken = default(CancellationToken))

test/Docker.DotNet.Tests/ISystemOperations.Tests.cs

@@ -220,6 +220,17 @@ public async Task PingAsync_Succeeds()
             await _client.System.PingAsync();
         }
 
+        [Fact]
+        public async Task AuthenticateAsync_Succeeds()
+        {
+            // The blank config goes to Dockerhub, which allows anonymous 
+            // reads, so the auth will definitely be accepted. This lets
+            // us check whether we correctly retrieve that acceptance.
+            var config = new AuthConfig();
+            var response = await _client.System.AuthenticateAsync(config);
+            Assert.Equal("Login Succeeded", response.Status);
+        }
+
         private class ProgressMessage : IProgress<Message>
         {
             internal Action<Message> _onMessageCalled;