Enable nullable on Diagnostics and Rewrite middleware (#28621)

Author: JamesNK

src/Middleware/Diagnostics/src/DeveloperExceptionPage/DeveloperExceptionPageExtensions.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using System;
 using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.Extensions.Options;

src/Middleware/Diagnostics/src/DeveloperExceptionPage/DeveloperExceptionPageMiddleware.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -165,10 +163,7 @@ private Task DisplayCompilationException(
             HttpContext context,
             ICompilationException compilationException)
         {
-            var model = new CompilationErrorPageModel
-            {
-                Options = _options,
-            };
+            var model = new CompilationErrorPageModel(_options);
 
             var errorPage = new CompilationErrorPage
             {

src/Middleware/Diagnostics/src/DeveloperExceptionPage/DeveloperExceptionPageOptions.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.Extensions.FileProviders;
 

src/Middleware/Diagnostics/src/DeveloperExceptionPage/Views/CompilationErrorModel.cs

@@ -12,10 +12,15 @@ namespace Microsoft.AspNetCore.Diagnostics.RazorViews
     /// </summary>
     internal class CompilationErrorPageModel
     {
+        public CompilationErrorPageModel(DeveloperExceptionPageOptions options)
+        {
+            Options = options;
+        }
+
         /// <summary>
         /// Options for what output to display.
         /// </summary>
-        public DeveloperExceptionPageOptions Options { get; set; }
+        public DeveloperExceptionPageOptions Options { get; }
 
         /// <summary>
         /// Detailed information about each parse or compilation error.
@@ -25,6 +30,6 @@ internal class CompilationErrorPageModel
         /// <summary>
         /// Gets the generated content that produced the corresponding <see cref="ErrorDetails"/>.
         /// </summary>
-        public IList<string> CompiledContent { get; } = new List<string>();
+        public IList<string?> CompiledContent { get; } = new List<string?>();
     }
-}
+}

src/Middleware/Diagnostics/src/DeveloperExceptionPage/Views/EndpointModel.cs

@@ -5,9 +5,9 @@ namespace Microsoft.AspNetCore.Diagnostics.RazorViews
 {
     internal class EndpointModel
     {
-        public string DisplayName { get; set; }
-        public string RoutePattern { get; set; }
+        public string? DisplayName { get; set; }
+        public string? RoutePattern { get; set; }
         public int? Order { get; set; }
-        public string HttpMethods { get; set; }
+        public string? HttpMethods { get; set; }
     }
 }

src/Middleware/Diagnostics/src/DiagnosticsLoggerExtensions.cs

@@ -13,17 +13,17 @@ internal static class DiagnosticsLoggerExtensions
             LoggerMessage.Define(LogLevel.Error, new EventId(1, "UnhandledException"), "An unhandled exception has occurred while executing the request.");
 
         // ExceptionHandlerMiddleware
-        private static readonly Action<ILogger, Exception> _responseStartedErrorHandler =
+        private static readonly Action<ILogger, Exception?> _responseStartedErrorHandler =
             LoggerMessage.Define(LogLevel.Warning, new EventId(2, "ResponseStarted"), "The response has already started, the error handler will not be executed.");
 
         private static readonly Action<ILogger, Exception> _errorHandlerException =
             LoggerMessage.Define(LogLevel.Error, new EventId(3, "Exception"), "An exception was thrown attempting to execute the error handler.");
 
-        private static readonly Action<ILogger, Exception> _errorHandlerNotFound =
+        private static readonly Action<ILogger, Exception?> _errorHandlerNotFound =
             LoggerMessage.Define(LogLevel.Warning, new EventId(4, "HandlerNotFound"), "No exception handler was found, rethrowing original exception.");
 
         // DeveloperExceptionPageMiddleware
-        private static readonly Action<ILogger, Exception> _responseStartedErrorPageMiddleware =
+        private static readonly Action<ILogger, Exception?> _responseStartedErrorPageMiddleware =
             LoggerMessage.Define(LogLevel.Warning, new EventId(2, "ResponseStarted"), "The response has already started, the error page middleware will not be executed.");
 
         private static readonly Action<ILogger, Exception> _displayErrorPageException =

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerExtensions.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using System;
 using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.AspNetCore.Http;

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerFeature.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using System;
 
 namespace Microsoft.AspNetCore.Diagnostics

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerMiddleware.cs

@@ -1,8 +1,6 @@
 // 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.
 
-#nullable enable
-
 using System;
 using System.Diagnostics;
 using System.Runtime.ExceptionServices;

src/Middleware/Diagnostics/src/ExceptionHandler/ExceptionHandlerOptions.cs

@@ -2,8 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using Microsoft.AspNetCore.Diagnostics;
-#nullable enable
-
 using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.Builder