Add explicit content types to 'no formatter' logging (#11213)

* Add explicit content types to 'no formatter' logging

* Remove dead code

src/Mvc/Mvc.Core/src/Infrastructure/DefaultOutputFormatterSelector.cs

@@ -147,14 +147,11 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
                 }
             }
 
-            if (selectedFormatter == null)
+            if (selectedFormatter != null)
             {
-                // No formatter supports this.
+                _logger.FormatterSelected(selectedFormatter, context);
-                _logger.NoFormatter(context);
-                return null;
             }
 
-            _logger.FormatterSelected(selectedFormatter, context);
             return selectedFormatter;
         }
 

src/Mvc/Mvc.Core/src/Infrastructure/ObjectResultExecutor.cs

@@ -148,7 +148,7 @@ namespace Microsoft.AspNetCore.Mvc.Infrastructure
             if (selectedFormatter == null)
             {
                 // No formatter supports this.
-                Logger.NoFormatter(formatterContext);
+                Logger.NoFormatter(formatterContext, result.ContentTypes);
 
                 context.HttpContext.Response.StatusCode = StatusCodes.Status406NotAcceptable;
                 return Task.CompletedTask;

src/Mvc/Mvc.Core/src/MvcCoreLoggerExtensions.cs

@@ -4,7 +4,6 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using System.Reflection;
 using System.Security.Claims;
@@ -28,8 +27,6 @@ namespace Microsoft.AspNetCore.Mvc
         public const string ActionFilter = "Action Filter";
         private static readonly string[] _noFilters = new[] { "None" };
 
-        private static readonly double TimestampToTicks = TimeSpan.TicksPerSecond / (double)Stopwatch.Frequency;
-
         private static readonly Action<ILogger, string, string, Exception> _actionExecuting;
         private static readonly Action<ILogger, string, MethodInfo, string, string, Exception> _controllerActionExecuting;
         private static readonly Action<ILogger, string, double, Exception> _actionExecuted;
@@ -73,7 +70,7 @@ namespace Microsoft.AspNetCore.Mvc
         private static readonly Action<ILogger, string, Exception> _localRedirectResultExecuting;
 
         private static readonly Action<ILogger, string, Exception> _objectResultExecuting;
-        private static readonly Action<ILogger, string, Exception> _noFormatter;
+        private static readonly Action<ILogger, IEnumerable<string>, Exception> _noFormatter;
         private static readonly Action<ILogger, IOutputFormatter, string, Exception> _formatterSelected;
         private static readonly Action<ILogger, string, Exception> _skippedContentNegotiation;
         private static readonly Action<ILogger, Exception> _noAcceptForNegotiation;
@@ -300,10 +297,10 @@ namespace Microsoft.AspNetCore.Mvc
                 new EventId(1, "LocalRedirectResultExecuting"),
                 "Executing LocalRedirectResult, redirecting to {Destination}.");
 
-            _noFormatter = LoggerMessage.Define<string>(
+            _noFormatter = LoggerMessage.Define<IEnumerable<string>>(
                 LogLevel.Warning,
                 new EventId(1, "NoFormatter"),
-                "No output formatter was found for content type '{ContentType}' to write the response.");
+                "No output formatter was found for content types '{ContentTypes}' to write the response.");
 
             _objectResultExecuting = LoggerMessage.Define<string>(
                 LogLevel.Information,
@@ -1017,11 +1014,19 @@ namespace Microsoft.AspNetCore.Mvc
 
         public static void NoFormatter(
             this ILogger logger,
-            OutputFormatterCanWriteContext formatterContext)
+            OutputFormatterCanWriteContext context,
+            MediaTypeCollection contentTypes)
         {
             if (logger.IsEnabled(LogLevel.Warning))
             {
-                _noFormatter(logger, Convert.ToString(formatterContext.ContentType), null);
+                var considered = new List<string>(contentTypes);
+
+                if (context.ContentType.HasValue)
+                {
+                    considered.Add(Convert.ToString(context.ContentType));
+                }
+
+                _noFormatter(logger, considered, null);
             }
         }
 

src/Mvc/Mvc.Core/test/MvcCoreLoggerExtensionsTest.cs

@@ -1,7 +1,9 @@
 // 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 Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.Extensions.Logging.Testing;
 using Moq;
 using Xunit;
@@ -282,6 +284,37 @@ namespace Microsoft.AspNetCore.Mvc
                 write.State.ToString());
         }
 
+        [Fact]
+        public void NoFormatter_LogsListOfContentTypes()
+        {
+            // Arrange
+            var testSink = new TestSink();
+            var loggerFactory = new TestLoggerFactory(testSink, enabled: true);
+            var logger = loggerFactory.CreateLogger("test");
+
+            var mediaTypes = new MediaTypeCollection
+            {
+                "application/problem+json",
+                "application/problem+xml",
+            };
+
+            var httpContext = Mock.Of<HttpContext>();
+            var context = new Mock<OutputFormatterCanWriteContext>(httpContext);
+
+            context.SetupGet(x => x.ContentType).Returns("application/json");
+
+            // Act
+            logger.NoFormatter(context.Object, mediaTypes);
+
+            // Assert
+            var write = Assert.Single(testSink.Writes);
+            Assert.Equal(
+                "No output formatter was found for content types " +
+                "'application/problem+json, application/problem+xml, application/json'" +
+                " to write the response.",
+                write.State.ToString());
+        }
+
         public interface IOrderedAuthorizeFilter : IAuthorizationFilter, IAsyncAuthorizationFilter, IOrderedFilter { }
 
         public interface IOrderedResourceFilter : IResourceFilter, IAsyncResourceFilter, IOrderedFilter { }