WebAPI V4 EntityReferences Link does not support $count query option.

 #205

Author: VikingsFan

OData/src/System.Web.OData/OData/Formatter/Serialization/ODataEntityReferenceLinksSerializer.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using System.Runtime.Serialization;
 using System.Web.Http;
+using System.Web.OData.Extensions;
 using System.Web.OData.Properties;
 using System.Web.OData.Routing;
 using Microsoft.OData.Core;
@@ -52,6 +53,11 @@ public override void WriteObject(object graph, Type type, ODataMessageWriter mes
                     {
                         Links = uris.Select(uri => new ODataEntityReferenceLink { Url = uri })
                     };
+
+                    if (writeContext.Request != null)
+                    {
+                        entityReferenceLinks.Count = writeContext.Request.ODataProperties().TotalCount;
+                    }
                 }
 
                 messageWriter.WriteEntityReferenceLinks(entityReferenceLinks);

OData/test/System.Web.OData.Test/OData/Formatter/Serialization/ODataEntityReferenceLinksSerializerTest.cs

@@ -1,7 +1,11 @@
 // Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
 
 using System.IO;
+using System.Linq;
+using System.Net.Http;
 using System.Runtime.Serialization;
+using System.Web.OData.Extensions;
+using System.Xml.Linq;
 using Microsoft.OData.Core;
 using Microsoft.TestCommon;
 
@@ -98,5 +102,49 @@ public void ODataEntityReferenceLinkSerializer_Serializes_UrisAndEntityReference
                 "\"value\":[{\"@odata.id\":\"http://uri1/\"},{\"@odata.id\":\"http://uri2/\"}]}",
                 result);
         }
+
+        public static TheoryDataSet<object> SerializationTestData2
+        {
+            get
+            {
+                Uri uri1 = new Uri("http://uri1");
+                return new TheoryDataSet<object>
+                {
+                    new Uri[] {uri1}
+                };
+            }
+        }
+
+        [Theory]
+        [PropertyData("SerializationTestData2")]
+        public void ODataEntityReferenceLinkSerializer_Serializes_UrisAndEntityReferenceLinks_WithCount(object uris)
+        {
+            // Arrange
+            ODataEntityReferenceLinksSerializer serializer = new ODataEntityReferenceLinksSerializer();
+            ODataSerializerContext writeContext = new ODataSerializerContext();
+            writeContext.Request = new HttpRequestMessage();
+            writeContext.Request.ODataProperties().TotalCount = 1;
+
+            MemoryStream stream = new MemoryStream();
+            IODataResponseMessage message = new ODataMessageWrapper(stream);
+
+            ODataMessageWriterSettings settings = new ODataMessageWriterSettings
+            {
+                ODataUri = new ODataUri { ServiceRoot = new Uri("http://any/") }
+            };
+
+            settings.SetContentType(ODataFormat.Json);
+            ODataMessageWriter writer = new ODataMessageWriter(message, settings);
+
+            // Act
+            serializer.WriteObject(uris, typeof(ODataEntityReferenceLinks), writer, writeContext);
+            stream.Seek(0, SeekOrigin.Begin);
+            string result = new StreamReader(stream).ReadToEnd();
+            Assert.Equal(
+                string.Format("{0},{1},{2}",
+                    "{\"@odata.context\":\"http://any/$metadata#Collection($ref)\"",
+                    "\"@odata.count\":1",
+                    "\"value\":[{\"@odata.id\":\"http://uri1/\"}]}"), result);
+        }
     }
 }