Improve linker friendliness for RouteOptions

src/Http/HttpAbstractions.slnf

@@ -2,15 +2,15 @@
   "solution": {
     "path": "..\\..\\AspNetCore.sln",
     "projects": [
+      "src\\Extensions\\Features\\src\\Microsoft.Extensions.Features.csproj",
+      "src\\Extensions\\Features\\test\\Microsoft.Extensions.Features.Tests.csproj",
       "src\\Hosting\\Abstractions\\src\\Microsoft.AspNetCore.Hosting.Abstractions.csproj",
       "src\\Hosting\\Hosting\\src\\Microsoft.AspNetCore.Hosting.csproj",
       "src\\Hosting\\Server.Abstractions\\src\\Microsoft.AspNetCore.Hosting.Server.Abstractions.csproj",
       "src\\Hosting\\TestHost\\src\\Microsoft.AspNetCore.TestHost.csproj",
       "src\\Http\\Authentication.Abstractions\\src\\Microsoft.AspNetCore.Authentication.Abstractions.csproj",
       "src\\Http\\Authentication.Core\\src\\Microsoft.AspNetCore.Authentication.Core.csproj",
       "src\\Http\\Authentication.Core\\test\\Microsoft.AspNetCore.Authentication.Core.Test.csproj",
-      "src\\Extensions\\Features\\src\\Microsoft.Extensions.Features.csproj",
-      "src\\Extensions\\Features\\test\\Microsoft.Extensions.Features.Tests.csproj",
       "src\\Http\\Headers\\src\\Microsoft.Net.Http.Headers.csproj",
       "src\\Http\\Headers\\test\\Microsoft.Net.Http.Headers.Tests.csproj",
       "src\\Http\\Http.Abstractions\\perf\\Microbenchmarks\\Microsoft.AspNetCore.Http.Abstractions.Microbenchmarks.csproj",
@@ -46,6 +46,7 @@
       "src\\Middleware\\HttpOverrides\\src\\Microsoft.AspNetCore.HttpOverrides.csproj",
       "src\\Middleware\\StaticFiles\\src\\Microsoft.AspNetCore.StaticFiles.csproj",
       "src\\ObjectPool\\src\\Microsoft.Extensions.ObjectPool.csproj",
+      "src\\Security\\Authorization\\Core\\src\\Microsoft.AspNetCore.Authorization.csproj",
       "src\\Security\\Authorization\\Policy\\src\\Microsoft.AspNetCore.Authorization.Policy.csproj",
       "src\\Servers\\Connections.Abstractions\\src\\Microsoft.AspNetCore.Connections.Abstractions.csproj",
       "src\\Servers\\IIS\\IISIntegration\\src\\Microsoft.AspNetCore.Server.IISIntegration.csproj",

src/Http/Routing/src/PublicAPI.Unshipped.txt

@@ -29,6 +29,8 @@ Microsoft.AspNetCore.Routing.EndpointGroupNameAttribute.EndpointGroupName.get ->
 Microsoft.AspNetCore.Routing.EndpointNameAttribute
 Microsoft.AspNetCore.Routing.EndpointNameAttribute.EndpointNameAttribute(string! endpointName) -> void
 Microsoft.AspNetCore.Routing.EndpointNameAttribute.EndpointName.get -> string!
+Microsoft.AspNetCore.Routing.RouteOptions.SetParameterPolicy(string! token, System.Type! type) -> void
+Microsoft.AspNetCore.Routing.RouteOptions.SetParameterPolicy<T>(string! token) -> void
 static Microsoft.AspNetCore.Builder.EndpointRouteBuilderExtensions.Map(this Microsoft.AspNetCore.Routing.IEndpointRouteBuilder! endpoints, Microsoft.AspNetCore.Routing.Patterns.RoutePattern! pattern, System.Delegate! handler) -> Microsoft.AspNetCore.Builder.RouteHandlerBuilder!
 static Microsoft.AspNetCore.Builder.EndpointRouteBuilderExtensions.Map(this Microsoft.AspNetCore.Routing.IEndpointRouteBuilder! endpoints, string! pattern, System.Delegate! handler) -> Microsoft.AspNetCore.Builder.RouteHandlerBuilder!
 static Microsoft.AspNetCore.Builder.EndpointRouteBuilderExtensions.MapDelete(this Microsoft.AspNetCore.Routing.IEndpointRouteBuilder! endpoints, string! pattern, System.Delegate! handler) -> Microsoft.AspNetCore.Builder.RouteHandlerBuilder!

src/Http/Routing/src/RouteOptions.cs

@@ -72,6 +72,7 @@ internal ICollection<EndpointDataSource> EndpointDataSources
         /// </summary>
         public IDictionary<string, Type> ConstraintMap
         {
+            [RequiresUnreferencedCode($"The linker cannot determine what constraints are being added via the ConstraintMap property. Prefer {nameof(RouteOptions)}.{nameof(SetParameterPolicy)} instead for setting constraints. This warning can be suppressed if this property is being used to read of delete constraints.")]
             get
             {
                 return _constraintTypeMap;
@@ -124,7 +125,32 @@ private static IDictionary<string, Type> GetDefaultConstraintMap()
             return defaults;
         }
 
-        // This API could be exposed on RouteOptions
+        /// <summary>
+        /// Adds or overwrites the parameter policy with the associated route pattern token.
+        /// </summary>
+        /// <typeparam name="T">The parameter policy type.</typeparam>
+        /// <param name="token">The route token used to apply the parameter policy.</param>
+        public void SetParameterPolicy<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]T>(string token) where T : IParameterPolicy
+        {
+            ConstraintMap[token] = typeof(T);
+        }
+
+        /// <summary>
+        /// Adds or overwrites the parameter policy with the associated route pattern token.
+        /// </summary>
+        /// <param name="token">The route token used to apply the parameter policy.</param>
+        /// <param name="type">The parameter policy type.</param>
+        /// <exception cref="InvalidOperationException">Throws an exception if the type is not an <see cref="IParameterPolicy"/>.</exception>
+        public void SetParameterPolicy(string token, [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] Type type)
+        {
+            if (!type.IsAssignableTo(typeof(IParameterPolicy)))
+            {
+                throw new InvalidOperationException($"{type} must implement {typeof(IParameterPolicy)}");
+            }
+
+            ConstraintMap[token] = type;
+        }
+
         private static void AddConstraint<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]TConstraint>(Dictionary<string, Type> constraintMap, string text) where TConstraint : IRouteConstraint
         {
             constraintMap[text] = typeof(TConstraint);

src/Http/Routing/test/UnitTests/DefaultInlineConstraintResolverTest.cs

@@ -269,6 +269,46 @@ public void ResolveConstraint_SupportsCustomConstraints()
             Assert.IsType<CustomRouteConstraint>(constraint);
         }
 
+        [Fact]
+        public void ResolveConstraint_SupportsCustomConstraintsUsingNonGenericOverload()
+        {
+            // Arrange
+            var routeOptions = new RouteOptions();
+            routeOptions.SetParameterPolicy("custom", typeof(CustomRouteConstraint));
+            var resolver = GetInlineConstraintResolver(routeOptions);
+
+            // Act
+            var constraint = resolver.ResolveConstraint("custom(argument)");
+
+            // Assert
+            Assert.IsType<CustomRouteConstraint>(constraint);
+        }
+
+        [Fact]
+        public void SetParameterPolicyThrowsIfTypeIsNotIParameterPolicy()
+        {
+            // Arrange
+            var routeOptions = new RouteOptions();
+            var ex = Assert.Throws<InvalidOperationException>(() => routeOptions.SetParameterPolicy("custom", typeof(string)));
+
+            Assert.Equal("System.String must implement Microsoft.AspNetCore.Routing.IParameterPolicy", ex.Message);
+        }
+
+        [Fact]
+        public void ResolveConstraint_SupportsCustomConstraintsUsingGenericOverloads()
+        {
+            // Arrange
+            var routeOptions = new RouteOptions();
+            routeOptions.SetParameterPolicy<CustomRouteConstraint>("custom");
+            var resolver = GetInlineConstraintResolver(routeOptions);
+
+            // Act
+            var constraint = resolver.ResolveConstraint("custom(argument)");
+
+            // Assert
+            Assert.IsType<CustomRouteConstraint>(constraint);
+        }
+
         [Fact]
         public void ResolveConstraint_CustomConstraintThatDoesNotImplementIRouteConstraint_Throws()
         {