From 34499dbe24034e402a483a9dd70722edab3a615f Mon Sep 17 00:00:00 2001
From: Kiran Challa <kichalla@microsoft.com>
Date: Tue, 24 Jul 2018 12:19:16 -0700
Subject: [PATCH] Added support for suppressing link generation for endpoints

---
 .../ISuppressLinkGenerationMetadata.cs          |  9 +++++++++
 .../RouteValuesBasedEndpointFinder.cs           |  7 +++++++
 .../RouteValueBasedEndpointFinderTest.cs        | 17 +++++++++++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 src/Microsoft.AspNetCore.Routing.Abstractions/ISuppressLinkGenerationMetadata.cs

diff --git a/src/Microsoft.AspNetCore.Routing.Abstractions/ISuppressLinkGenerationMetadata.cs b/src/Microsoft.AspNetCore.Routing.Abstractions/ISuppressLinkGenerationMetadata.cs
new file mode 100644
index 0000000000..2e6a7da5d8
--- /dev/null
+++ b/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
+    {
+    }
+}
diff --git a/src/Microsoft.AspNetCore.Routing/RouteValuesBasedEndpointFinder.cs b/src/Microsoft.AspNetCore.Routing/RouteValuesBasedEndpointFinder.cs
index 2c3afaf55d..e4fc5c16a7 100644
--- a/src/Microsoft.AspNetCore.Routing/RouteValuesBasedEndpointFinder.cs
+++ b/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 };
diff --git a/test/Microsoft.AspNetCore.Routing.Tests/RouteValueBasedEndpointFinderTest.cs b/test/Microsoft.AspNetCore.Routing.Tests/RouteValueBasedEndpointFinderTest.cs
index 6296604d2a..fab9c41600 100644
--- a/test/Microsoft.AspNetCore.Routing.Tests/RouteValueBasedEndpointFinderTest.cs
+++ b/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 { }
     }
 }