Implement AddRoutingCore to support excluding Regex.

Author: mitchdenny

src/DefaultBuilder/src/WebApplicationBuilder.cs

@@ -59,6 +59,11 @@ internal WebApplicationBuilder(WebApplicationOptions options, Action<IHostBuilde
 
         bootstrapHostBuilder.ConfigureWebHostDefaults(webHostBuilder =>
         {
+            webHostBuilder.ConfigureServices(services =>
+            {
+                services.AddRouting();
+            });
+
             // Runs inline.
             webHostBuilder.Configure(ConfigureApplication);
 
@@ -136,6 +141,11 @@ internal WebApplicationBuilder(WebApplicationOptions options, bool slim, Action<
             {
                 AspNetCore.WebHost.UseKestrel(webHostBuilder);
 
+                webHostBuilder.ConfigureServices(services =>
+                {
+                    services.AddRoutingCore();
+                });
+
                 webHostBuilder.Configure(ConfigureEmptyApplication);
 
                 webHostBuilder.UseSetting(WebHostDefaults.ApplicationKey, _hostApplicationBuilder.Environment.ApplicationName ?? "");

src/DefaultBuilder/src/WebHost.cs

@@ -257,7 +257,7 @@ internal static void UseKestrel(IWebHostBuilder builder)
             services.AddTransient<IStartupFilter, ForwardedHeadersStartupFilter>();
             services.AddTransient<IConfigureOptions<ForwardedHeadersOptions>, ForwardedHeadersOptionsSetup>();
 
-            services.AddRouting();
+            services.AddRoutingCore();
         });
     }
 

src/Http/Routing/src/DependencyInjection/RoutingServiceCollectionExtensions.cs

@@ -20,12 +20,20 @@ namespace Microsoft.Extensions.DependencyInjection;
 /// </summary>
 public static class RoutingServiceCollectionExtensions
 {
+    public static IServiceCollection AddRouting(this IServiceCollection services)
+    {
+        return services.AddRoutingCore(routeOptions =>
+        {
+            routeOptions.AddRegexConstraints();
+        });
+    }
+
     /// <summary>
     /// Adds services required for routing requests.
     /// </summary>
     /// <param name="services">The <see cref="IServiceCollection"/> to add the services to.</param>
     /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
-    public static IServiceCollection AddRouting(this IServiceCollection services)
+    public static IServiceCollection AddRoutingCore(this IServiceCollection services)
     {
         ArgumentNullException.ThrowIfNull(services);
 
@@ -101,21 +109,32 @@ public static IServiceCollection AddRouting(this IServiceCollection services)
         return services;
     }
 
+    public static IServiceCollection AddRouting(
+        this IServiceCollection services,
+        Action<RouteOptions> configureOptions)
+    {
+        return services.AddRoutingCore(routeOptions =>
+        {
+            routeOptions.AddRegexConstraints();
+            configureOptions(routeOptions);
+        });
+    }
+
     /// <summary>
     /// Adds services required for routing requests.
     /// </summary>
     /// <param name="services">The <see cref="IServiceCollection"/> to add the services to.</param>
     /// <param name="configureOptions">The routing options to configure the middleware with.</param>
     /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
-    public static IServiceCollection AddRouting(
+    public static IServiceCollection AddRoutingCore(
         this IServiceCollection services,
         Action<RouteOptions> configureOptions)
     {
         ArgumentNullException.ThrowIfNull(services);
         ArgumentNullException.ThrowIfNull(configureOptions);
 
         services.Configure(configureOptions);
-        services.AddRouting();
+        services.AddRoutingCore();
 
         return services;
     }

src/Http/Routing/src/RouteOptions.cs

@@ -4,6 +4,7 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.AspNetCore.Routing.Constraints;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNetCore.Routing;
 
@@ -89,6 +90,16 @@ public IDictionary<string, Type> ConstraintMap
     /// </summary>
     internal IDictionary<string, Type> TrimmerSafeConstraintMap => _constraintTypeMap;
 
+    /// <summary>
+    /// Add Regex-based constraints to the constraint map (e.g. alpha and regex constraint types). This is called automatically by <see cref="RoutingServiceCollectionExtensions.AddRouting(IServiceCollection)"/>.
+    /// </summary>
+    public void AddRegexConstraints()
+    {
+        // Regex-based constraints
+        AddConstraint<AlphaRouteConstraint>(_constraintTypeMap, "alpha");
+        AddConstraint<RegexInlineRouteConstraint>(_constraintTypeMap, "regex");
+    }
+
     private static IDictionary<string, Type> GetDefaultConstraintMap()
     {
         var defaults = new Dictionary<string, Type>(StringComparer.OrdinalIgnoreCase);
@@ -113,10 +124,6 @@ private static IDictionary<string, Type> GetDefaultConstraintMap()
         AddConstraint<MaxRouteConstraint>(defaults, "max");
         AddConstraint<RangeRouteConstraint>(defaults, "range");
 
-        // Regex-based constraints
-        AddConstraint<AlphaRouteConstraint>(defaults, "alpha");
-        AddConstraint<RegexInlineRouteConstraint>(defaults, "regex");
-
         AddConstraint<RequiredRouteConstraint>(defaults, "required");
 
         // Files
@@ -152,7 +159,7 @@ public void SetParameterPolicy(string token, [DynamicallyAccessedMembers(Dynamic
         _constraintTypeMap[token] = type;
     }
 
-    private static void AddConstraint<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] TConstraint>(Dictionary<string, Type> constraintMap, string text) where TConstraint : IRouteConstraint
+    private static void AddConstraint<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] TConstraint>(IDictionary<string, Type> constraintMap, string text) where TConstraint : IRouteConstraint
     {
         constraintMap[text] = typeof(TConstraint);
     }