From 97f54c532bddfb584ebe2f6474ce985c09337410 Mon Sep 17 00:00:00 2001
From: Ryan Nowak <nowakra@gmail.com>
Date: Wed, 15 Aug 2018 20:57:40 -0700
Subject: [PATCH] Support supression of matching for endpoints

---
 .../ISuppressMatchingMetadata.cs              | 13 ++++++++++++
 .../Internal/DfaGraphWriter.cs                |  2 +-
 .../Matching/DataSourceDependentMatcher.cs    |  2 +-
 .../SuppressMatchingMetadata.cs               | 13 ++++++++++++
 .../DataSourceDependentMatcherTest.cs         | 21 +++++++++++++++++++
 5 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 src/Microsoft.AspNetCore.Routing/ISuppressMatchingMetadata.cs
 create mode 100644 src/Microsoft.AspNetCore.Routing/SuppressMatchingMetadata.cs

diff --git a/src/Microsoft.AspNetCore.Routing/ISuppressMatchingMetadata.cs b/src/Microsoft.AspNetCore.Routing/ISuppressMatchingMetadata.cs
new file mode 100644
index 0000000000..8baa0e0a77
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Routing/ISuppressMatchingMetadata.cs
@@ -0,0 +1,13 @@
+// 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
+{
+    /// <summary>
+    /// Metadata used to prevent URL matching. The associated endpoint will not be
+    /// considered URL matching for incoming requests.
+    /// </summary>
+    public interface ISuppressMatchingMetadata
+    {
+    }
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNetCore.Routing/Internal/DfaGraphWriter.cs b/src/Microsoft.AspNetCore.Routing/Internal/DfaGraphWriter.cs
index 9a1c8773f3..2d036ac76b 100644
--- a/src/Microsoft.AspNetCore.Routing/Internal/DfaGraphWriter.cs
+++ b/src/Microsoft.AspNetCore.Routing/Internal/DfaGraphWriter.cs
@@ -39,7 +39,7 @@ namespace Microsoft.AspNetCore.Routing.Internal
             for (var i = 0; i < endpoints.Count; i++)
             {
                 var endpoint = endpoints[i] as MatcherEndpoint;
-                if (endpoint != null)
+                if (endpoint != null && endpoint.Metadata.GetMetadata<ISuppressMatchingMetadata>() == null)
                 {
                     builder.AddEndpoint(endpoint);
                 }
diff --git a/src/Microsoft.AspNetCore.Routing/Matching/DataSourceDependentMatcher.cs b/src/Microsoft.AspNetCore.Routing/Matching/DataSourceDependentMatcher.cs
index 5ff901b96d..9dced3dc3d 100644
--- a/src/Microsoft.AspNetCore.Routing/Matching/DataSourceDependentMatcher.cs
+++ b/src/Microsoft.AspNetCore.Routing/Matching/DataSourceDependentMatcher.cs
@@ -40,7 +40,7 @@ namespace Microsoft.AspNetCore.Routing.Matching
                 // register other endpoint types, which are non-routable, and it's
                 // ok that we won't route to them.
                 var endpoint = endpoints[i] as MatcherEndpoint;
-                if (endpoint != null)
+                if (endpoint != null && endpoint.Metadata.GetMetadata<ISuppressMatchingMetadata>() == null)
                 {
                     builder.AddEndpoint(endpoint);
                 }
diff --git a/src/Microsoft.AspNetCore.Routing/SuppressMatchingMetadata.cs b/src/Microsoft.AspNetCore.Routing/SuppressMatchingMetadata.cs
new file mode 100644
index 0000000000..da7a3bce1d
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Routing/SuppressMatchingMetadata.cs
@@ -0,0 +1,13 @@
+// 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
+{
+    /// <summary>
+    /// Metadata used to prevent URL matching. The associated endpoint will not be
+    /// considered URL matching for incoming requests.
+    /// </summary>
+    public sealed class SuppressMatchingMetadata : ISuppressMatchingMetadata
+    {
+    }
+}
diff --git a/test/Microsoft.AspNetCore.Routing.Tests/Matching/DataSourceDependentMatcherTest.cs b/test/Microsoft.AspNetCore.Routing.Tests/Matching/DataSourceDependentMatcherTest.cs
index 07c1db9537..74b87b56fc 100644
--- a/test/Microsoft.AspNetCore.Routing.Tests/Matching/DataSourceDependentMatcherTest.cs
+++ b/test/Microsoft.AspNetCore.Routing.Tests/Matching/DataSourceDependentMatcherTest.cs
@@ -67,6 +67,27 @@ namespace Microsoft.AspNetCore.Routing.Matching
             Assert.Empty(inner.Endpoints);
         }
 
+        [Fact]
+        public void Matcher_Ignores_SuppressedEndpoint()
+        {
+            // Arrange
+            var dataSource = new DynamicEndpointDataSource();
+            var endpoint = new MatcherEndpoint(
+                MatcherEndpoint.EmptyInvoker,
+                RoutePatternFactory.Parse("/"),
+                0,
+                new EndpointMetadataCollection(new SuppressMatchingMetadata()),
+                "test");
+            dataSource.AddEndpoint(endpoint);
+
+            // Act
+            var matcher = new DataSourceDependentMatcher(dataSource, TestMatcherBuilder.Create);
+
+            // Assert
+            var inner = Assert.IsType<TestMatcher>(matcher.CurrentMatcher);
+            Assert.Empty(inner.Endpoints);
+        }
+
         [Fact]
         public void Cache_Reinitializes_WhenDataSourceChanges()
         {