Nullable followup for Routing (#23474)

* Nullable followup for routing.

* Update nullability based on usage
* Use nullable enable in a few files

* More nullable

Author: pranavkm

src/Http/Http.Abstractions/src/Routing/RouteValueDictionary.cs

@@ -512,7 +512,7 @@ public bool TryGetValue(string key, out object? value)
             return TryGetValueSlow(key, out value);
         }
 
-        private bool TryGetValueSlow(string key, [NotNullWhen(true)] out object? value)
+        private bool TryGetValueSlow(string key, out object? value)
         {
             if (_propertyStorage != null)
             {

src/Http/Routing.Abstractions/ref/Microsoft.AspNetCore.Routing.Abstractions.netcoreapp.cs

@@ -5,35 +5,35 @@ namespace Microsoft.AspNetCore.Routing
 {
     public partial interface IOutboundParameterTransformer : Microsoft.AspNetCore.Routing.IParameterPolicy
     {
-        string TransformOutbound(object value);
+        string? TransformOutbound(object? value);
     }
     public partial interface IParameterPolicy
     {
     }
     public partial interface IRouteConstraint : Microsoft.AspNetCore.Routing.IParameterPolicy
     {
-        bool Match(Microsoft.AspNetCore.Http.HttpContext httpContext, Microsoft.AspNetCore.Routing.IRouter route, string routeKey, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteDirection routeDirection);
+        bool Match(Microsoft.AspNetCore.Http.HttpContext? httpContext, Microsoft.AspNetCore.Routing.IRouter route, string routeKey, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteDirection routeDirection);
     }
     public partial interface IRouteHandler
     {
         Microsoft.AspNetCore.Http.RequestDelegate GetRequestHandler(Microsoft.AspNetCore.Http.HttpContext httpContext, Microsoft.AspNetCore.Routing.RouteData routeData);
     }
     public partial interface IRouter
     {
-        Microsoft.AspNetCore.Routing.VirtualPathData GetVirtualPath(Microsoft.AspNetCore.Routing.VirtualPathContext context);
+        Microsoft.AspNetCore.Routing.VirtualPathData? GetVirtualPath(Microsoft.AspNetCore.Routing.VirtualPathContext context);
         System.Threading.Tasks.Task RouteAsync(Microsoft.AspNetCore.Routing.RouteContext context);
     }
     public partial interface IRoutingFeature
     {
-        Microsoft.AspNetCore.Routing.RouteData RouteData { get; set; }
+        Microsoft.AspNetCore.Routing.RouteData? RouteData { get; set; }
     }
     public abstract partial class LinkGenerator
     {
         protected LinkGenerator() { }
-        public abstract string GetPathByAddress<TAddress>(Microsoft.AspNetCore.Http.HttpContext httpContext, TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteValueDictionary? ambientValues = null, Microsoft.AspNetCore.Http.PathString? pathBase = default(Microsoft.AspNetCore.Http.PathString?), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
-        public abstract string GetPathByAddress<TAddress>(TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
-        public abstract string GetUriByAddress<TAddress>(Microsoft.AspNetCore.Http.HttpContext httpContext, TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteValueDictionary? ambientValues = null, string? scheme = null, Microsoft.AspNetCore.Http.HostString? host = default(Microsoft.AspNetCore.Http.HostString?), Microsoft.AspNetCore.Http.PathString? pathBase = default(Microsoft.AspNetCore.Http.PathString?), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
-        public abstract string GetUriByAddress<TAddress>(TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, string scheme, Microsoft.AspNetCore.Http.HostString host, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
+        public abstract string? GetPathByAddress<TAddress>(Microsoft.AspNetCore.Http.HttpContext httpContext, TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteValueDictionary? ambientValues = null, Microsoft.AspNetCore.Http.PathString? pathBase = default(Microsoft.AspNetCore.Http.PathString?), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
+        public abstract string? GetPathByAddress<TAddress>(TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
+        public abstract string? GetUriByAddress<TAddress>(Microsoft.AspNetCore.Http.HttpContext httpContext, TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteValueDictionary? ambientValues = null, string? scheme = null, Microsoft.AspNetCore.Http.HostString? host = default(Microsoft.AspNetCore.Http.HostString?), Microsoft.AspNetCore.Http.PathString? pathBase = default(Microsoft.AspNetCore.Http.PathString?), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
+        public abstract string? GetUriByAddress<TAddress>(TAddress address, Microsoft.AspNetCore.Routing.RouteValueDictionary values, string scheme, Microsoft.AspNetCore.Http.HostString host, Microsoft.AspNetCore.Http.PathString pathBase = default(Microsoft.AspNetCore.Http.PathString), Microsoft.AspNetCore.Http.FragmentString fragment = default(Microsoft.AspNetCore.Http.FragmentString), Microsoft.AspNetCore.Routing.LinkOptions? options = null);
     }
     public partial class LinkOptions
     {
@@ -57,13 +57,13 @@ public RouteData(Microsoft.AspNetCore.Routing.RouteValueDictionary values) { }
         public Microsoft.AspNetCore.Routing.RouteValueDictionary DataTokens { get { throw null; } }
         public System.Collections.Generic.IList<Microsoft.AspNetCore.Routing.IRouter> Routers { get { throw null; } }
         public Microsoft.AspNetCore.Routing.RouteValueDictionary Values { get { throw null; } }
-        public Microsoft.AspNetCore.Routing.RouteData.RouteDataSnapshot PushState(Microsoft.AspNetCore.Routing.IRouter router, Microsoft.AspNetCore.Routing.RouteValueDictionary values, Microsoft.AspNetCore.Routing.RouteValueDictionary dataTokens) { throw null; }
+        public Microsoft.AspNetCore.Routing.RouteData.RouteDataSnapshot PushState(Microsoft.AspNetCore.Routing.IRouter? router, Microsoft.AspNetCore.Routing.RouteValueDictionary? values, Microsoft.AspNetCore.Routing.RouteValueDictionary? dataTokens) { throw null; }
         [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
         public readonly partial struct RouteDataSnapshot
         {
             private readonly object _dummy;
             private readonly int _dummyPrimitive;
-            public RouteDataSnapshot(Microsoft.AspNetCore.Routing.RouteData routeData, Microsoft.AspNetCore.Routing.RouteValueDictionary dataTokens, System.Collections.Generic.IList<Microsoft.AspNetCore.Routing.IRouter> routers, Microsoft.AspNetCore.Routing.RouteValueDictionary values) { throw null; }
+            public RouteDataSnapshot(Microsoft.AspNetCore.Routing.RouteData routeData, Microsoft.AspNetCore.Routing.RouteValueDictionary? dataTokens, System.Collections.Generic.IList<Microsoft.AspNetCore.Routing.IRouter>? routers, Microsoft.AspNetCore.Routing.RouteValueDictionary? values) { throw null; }
             public void Restore() { }
         }
     }

src/Http/Routing.Abstractions/src/IOutboundParameterTransformer.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// 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.
 
 namespace Microsoft.AspNetCore.Routing
@@ -14,6 +14,6 @@ public interface IOutboundParameterTransformer : IParameterPolicy
         /// </summary>
         /// <param name="value">The route value to transform.</param>
         /// <returns>The transformed value.</returns>
-        string TransformOutbound(object value);
+        string? TransformOutbound(object? value);
     }
 }

src/Http/Routing.Abstractions/src/IRouteConstraint.cs

@@ -24,7 +24,7 @@ public interface IRouteConstraint : IParameterPolicy
         /// </param>
         /// <returns><c>true</c> if the URL parameter contains a valid value; otherwise, <c>false</c>.</returns>
         bool Match(
-            HttpContext httpContext,
+            HttpContext? httpContext,
             IRouter route,
             string routeKey,
             RouteValueDictionary values,

src/Http/Routing.Abstractions/src/IRouter.cs

@@ -9,6 +9,6 @@ public interface IRouter
     {
         Task RouteAsync(RouteContext context);
 
-        VirtualPathData GetVirtualPath(VirtualPathContext context);
+        VirtualPathData? GetVirtualPath(VirtualPathContext context);
     }
 }

src/Http/Routing.Abstractions/src/IRoutingFeature.cs

@@ -1,6 +1,8 @@
 // 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
+
 namespace Microsoft.AspNetCore.Routing
 {
     /// <summary>
@@ -11,6 +13,6 @@ public interface IRoutingFeature
         /// <summary>
         /// Gets or sets the <see cref="Routing.RouteData"/> associated with the current request.
         /// </summary>
-        RouteData RouteData { get; set; }
+        RouteData? RouteData { get; set; }
     }
 }

src/Http/Routing.Abstractions/src/LinkGenerator.cs

@@ -11,13 +11,13 @@ namespace Microsoft.AspNetCore.Routing
     /// <remarks>
     /// <para>
     /// Generating URIs in endpoint routing occurs in two phases. First, an address is bound to a list of
-    /// endpoints that match the address. Secondly, each endpoint's <c>RoutePattern</c> is evaluated, until 
+    /// endpoints that match the address. Secondly, each endpoint's <c>RoutePattern</c> is evaluated, until
     /// a route pattern that matches the supplied values is found. The resulting output is combined with
     /// the other URI parts supplied to the link generator and returned.
     /// </para>
     /// <para>
     /// The methods provided by the <see cref="LinkGenerator"/> type are general infrastructure, and support
-    /// the standard link generator functionality for any type of address. The most convenient way to use 
+    /// the standard link generator functionality for any type of address. The most convenient way to use
     /// <see cref="LinkGenerator"/> is through extension methods that perform operations for a specific
     /// address type.
     /// </para>
@@ -30,7 +30,7 @@ public abstract class LinkGenerator
         /// <typeparam name="TAddress">The address type.</typeparam>
         /// <param name="httpContext">The <see cref="HttpContext"/> associated with the current request.</param>
         /// <param name="address">The address value. Used to resolve endpoints.</param>
-        /// <param name="values">The route values. Used to expand parameters in the route template. Optional.</param>
+        /// <param name="values">The route values. Used to expand parameters in the route template.</param>
         /// <param name="ambientValues">The values associated with the current request. Optional.</param>
         /// <param name="pathBase">
         /// An optional URI path base. Prepended to the path in the resulting URI. If not provided, the value of <see cref="HttpRequest.PathBase"/> will be used.
@@ -41,7 +41,7 @@ public abstract class LinkGenerator
         /// names from <c>RouteOptions</c>.
         /// </param>
         /// <returns>A URI with an absolute path, or <c>null</c>.</returns>
-        public abstract string GetPathByAddress<TAddress>(
+        public abstract string? GetPathByAddress<TAddress>(
             HttpContext httpContext,
             TAddress address,
             RouteValueDictionary values,
@@ -55,15 +55,15 @@ public abstract string GetPathByAddress<TAddress>(
         /// </summary>
         /// <typeparam name="TAddress">The address type.</typeparam>
         /// <param name="address">The address value. Used to resolve endpoints.</param>
-        /// <param name="values">The route values. Used to expand parameters in the route template. Optional.</param>
+        /// <param name="values">The route values. Used to expand parameters in the route template.</param>
         /// <param name="pathBase">An optional URI path base. Prepended to the path in the resulting URI.</param>
         /// <param name="fragment">An optional URI fragment. Appended to the resulting URI.</param>
         /// <param name="options">
         /// An optional <see cref="LinkOptions"/>. Settings on provided object override the settings with matching
         /// names from <c>RouteOptions</c>.
         /// </param>
         /// <returns>A URI with an absolute path, or <c>null</c>.</returns>
-        public abstract string GetPathByAddress<TAddress>(
+        public abstract string? GetPathByAddress<TAddress>(
             TAddress address,
             RouteValueDictionary values,
             PathString pathBase = default,
@@ -76,7 +76,7 @@ public abstract string GetPathByAddress<TAddress>(
         /// <typeparam name="TAddress">The address type.</typeparam>
         /// <param name="httpContext">The <see cref="HttpContext"/> associated with the current request.</param>
         /// <param name="address">The address value. Used to resolve endpoints.</param>
-        /// <param name="values">The route values. Used to expand parameters in the route template. Optional.</param>
+        /// <param name="values">The route values. Used to expand parameters in the route template.</param>
         /// <param name="ambientValues">The values associated with the current request. Optional.</param>
         /// <param name="scheme">
         /// The URI scheme, applied to the resulting URI. Optional. If not provided, the value of <see cref="HttpRequest.Scheme"/> will be used.
@@ -102,7 +102,7 @@ public abstract string GetPathByAddress<TAddress>(
         /// your deployment environment.
         /// </para>
         /// </remarks>
-        public abstract string GetUriByAddress<TAddress>(
+        public abstract string? GetUriByAddress<TAddress>(
             HttpContext httpContext,
             TAddress address,
             RouteValueDictionary values,
@@ -118,7 +118,7 @@ public abstract string GetUriByAddress<TAddress>(
         /// </summary>
         /// <typeparam name="TAddress">The address type.</typeparam>
         /// <param name="address">The address value. Used to resolve endpoints.</param>
-        /// <param name="values">The route values. Used to expand parameters in the route template. Optional.</param>
+        /// <param name="values">The route values. Used to expand parameters in the route template.</param>
         /// <param name="scheme">The URI scheme, applied to the resulting URI.</param>
         /// <param name="host">
         /// The URI host/authority, applied to the resulting URI.
@@ -139,7 +139,7 @@ public abstract string GetUriByAddress<TAddress>(
         /// your deployment environment.
         /// </para>
         /// </remarks>
-        public abstract string GetUriByAddress<TAddress>(
+        public abstract string? GetUriByAddress<TAddress>(
             TAddress address,
             RouteValueDictionary values,
             string scheme,