Added support for suppressing link generation for endpoints

src/Microsoft.AspNetCore.Routing.Abstractions/ISuppressLinkGenerationMetadata.cs

@@ -0,0 +1,9 @@
+// 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
+{
+    public interface ISuppressLinkGenerationMetadata
+    {
+    }
+}

src/Microsoft.AspNetCore.Routing/RouteValuesBasedEndpointFinder.cs

@@ -107,6 +107,13 @@ namespace Microsoft.AspNetCore.Routing
             var endpoints = _endpointDataSource.Endpoints.OfType<MatcherEndpoint>();
             foreach (var endpoint in endpoints)
             {
+                // Do not consider an endpoint for link generation if the following marker metadata is on it
+                var suppressLinkGeneration = endpoint.Metadata.GetMetadata<ISuppressLinkGenerationMetadata>();
+                if (suppressLinkGeneration != null)
+                {
+                    continue;
+                }
+
                 var entry = CreateOutboundRouteEntry(endpoint);
 
                 var outboundMatch = new OutboundMatch() { Entry = entry };

test/Microsoft.AspNetCore.Routing.Tests/RouteValueBasedEndpointFinderTest.cs

@@ -224,6 +224,21 @@ namespace Microsoft.AspNetCore.Routing
             Assert.Same(expected, actual);
         }
 
+        [Fact]
+        public void GetOutboundMatches_DoesNotInclude_EndpointsWithSuppressLinkGenerationMetadata()
+        {
+            // Arrange
+            var endpoint = CreateEndpoint(
+                "/a",
+                metadataCollection: new EndpointMetadataCollection(new[] { new SuppressLinkGenerationMetadata() }));
+
+            // Act
+            var finder = CreateEndpointFinder(endpoint);
+
+            // Assert
+            Assert.Empty(finder.AllMatches);
+        }
+
         private CustomRouteValuesBasedEndpointFinder CreateEndpointFinder(params Endpoint[] endpoints)
         {
             return CreateEndpointFinder(new DefaultEndpointDataSource(endpoints));
@@ -304,5 +319,7 @@ namespace Microsoft.AspNetCore.Routing
                 return matches;
             }
         }
+
+        private class SuppressLinkGenerationMetadata : ISuppressLinkGenerationMetadata { }
     }
 }