[Routing] [Mvc] Support RoutePattern required values in matcher and link generator

src/Mvc/benchmarks/Microsoft.AspNetCore.Mvc.Performance/MvcEndpointDatasourceBenchmark.cs

@@ -58,6 +58,8 @@ public void AttributeRouteEndpoints()
         {
             var endpointDataSource = CreateMvcEndpointDataSource(_attributeActionProvider);
             var endpoints = endpointDataSource.Endpoints;
+
+            AssertHasEndpoints(endpoints);
         }
 
         [Benchmark]
@@ -66,6 +68,8 @@ public void ConventionalEndpoints()
             var endpointDataSource = CreateMvcEndpointDataSource(_conventionalActionProvider);
             endpointDataSource.ConventionalEndpointInfos.AddRange(_conventionalEndpointInfos);
             var endpoints = endpointDataSource.Endpoints;
+
+            AssertHasEndpoints(endpoints);
         }
 
         private ActionDescriptor CreateAttributeRoutedAction(int id)
@@ -110,11 +114,20 @@ private MvcEndpointDataSource CreateMvcEndpointDataSource(
             var dataSource = new MvcEndpointDataSource(
                 actionDescriptorCollectionProvider,
                 new MvcEndpointInvokerFactory(new ActionInvokerFactory(Array.Empty<IActionInvokerProvider>())),
-                new MockParameterPolicyFactory());
+                new MockParameterPolicyFactory(),
+                new MockRoutePatternTransformer());
 
             return dataSource;
         }
 
+        private class MockRoutePatternTransformer : RoutePatternTransformer
+        {
+            public override RoutePattern SubstituteRequiredValues(RoutePattern original, object requiredValues)
+            {
+                return original;
+            }
+        }
+
         private class MockActionDescriptorCollectionProvider : IActionDescriptorCollectionProvider
         {
             public MockActionDescriptorCollectionProvider(List<ActionDescriptor> actionDescriptors)
@@ -137,5 +150,13 @@ public override IParameterPolicy Create(RoutePatternParameterPart parameter, IPa
                 throw new NotImplementedException();
             }
         }
+
+        private static void AssertHasEndpoints(IReadOnlyList<Http.Endpoint> endpoints)
+        {
+            if (endpoints.Count == 0)
+            {
+                throw new InvalidOperationException("Expected endpoints from data source.");
+            }
+        }
     }
 }

src/Mvc/samples/MvcSandbox/SlugifyParameterTransformer.cs

@@ -0,0 +1,19 @@
+// 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 System;
+using System.Text.RegularExpressions;
+using Microsoft.AspNetCore.Routing;
+
+namespace MvcSandbox
+{
+    public class SlugifyParameterTransformer : IOutboundParameterTransformer
+    {
+        public string TransformOutbound(object value)
+        {
+            // Slugify value
+            return value == null ? null : Regex.Replace(value.ToString(), "([a-z])([A-Z])", "$1-$2", RegexOptions.None, TimeSpan.FromMilliseconds(100)).ToLower();
+        }
+    }
+}
+

src/Mvc/samples/MvcSandbox/Startup.cs

@@ -5,11 +5,13 @@
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
+using Microsoft.AspNetCore.Routing.Internal;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
@@ -20,6 +22,10 @@ public class Startup
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
+            services.AddRouting(options =>
+            {
+                options.ConstraintMap["slugify"] = typeof(SlugifyParameterTransformer);
+            });
             services.AddMvc().SetCompatibilityVersion(Microsoft.AspNetCore.Mvc.CompatibilityVersion.Latest);
         }
 
@@ -37,6 +43,27 @@ public void Configure(IApplicationBuilder app)
                     name: "default",
                     template: "{controller=Home}/{action=Index}/{id?}");
 
+                builder.MapControllerRoute(
+                    name: "transform",
+                    template: "Transform/{controller:slugify=Home}/{action:slugify=Index}/{id?}",
+                    defaults: null,
+                    constraints: new { controller = "Home" });
+
+                builder.MapGet(
+                    "/graph",
+                    "DFA Graph",
+                    (httpContext) =>
+                    {
+                        using (var writer = new StreamWriter(httpContext.Response.Body, Encoding.UTF8, 1024, leaveOpen: true))
+                        {
+                            var graphWriter = httpContext.RequestServices.GetRequiredService<DfaGraphWriter>();
+                            var dataSource = httpContext.RequestServices.GetRequiredService<EndpointDataSource>();
+                            graphWriter.Write(dataSource, writer);
+                        }
+
+                        return Task.CompletedTask;
+                    });
+
                 builder.MapApplication();
 
                 builder.MapHealthChecks("/healthz");
@@ -50,7 +77,7 @@ public void Configure(IApplicationBuilder app)
 
         private static Task WriteEndpoints(HttpContext httpContext)
         {
-            var dataSource = httpContext.RequestServices.GetRequiredService<CompositeEndpointDataSource>();
+            var dataSource = httpContext.RequestServices.GetRequiredService<EndpointDataSource>();
 
             var sb = new StringBuilder();
             sb.AppendLine("Endpoints:");
@@ -81,6 +108,7 @@ public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
                     factory
                         .AddConsole()
                         .AddDebug();
+                    factory.SetMinimumLevel(LogLevel.Trace);
                 })
                 .UseIISIntegration()
                 .UseKestrel()