Retrieve the navigation properties if there's on $expand for delta serializer

Author: xuzhg

src/Microsoft.AspNet.OData.Shared/Formatter/Serialization/ODataResourceSerializer.cs

@@ -1808,7 +1808,7 @@ private IEnumerable<KeyValuePair<IEdmNavigationProperty, Type>> GetNavigationPro
 
             if (navigationProperties == null)
             {
-                yield break;
+                navigationProperties = resourceContext.StructuredType.DeclaredNavigationProperties();
             }
 
             if (resourceContext.EdmObject is IDelta changedObject)

test/E2ETest/Microsoft.Test.E2E.AspNet.OData/BulkOperation/BulkOperationTest.cs

@@ -42,7 +42,69 @@ protected override void UpdateConfiguration(WebRouteConfiguration configuration)
         }
 
         #region Update
-         
+
+        [Fact]
+        public async Task PatchEmployee_WithNestedFriends_WithNestedOrders_IsSerializedSuccessfully()
+        {
+            //Arrange
+            string requestUri = this.BaseAddress + "/convention/Employees";
+            var content = @"{
+                '@odata.context':'http://host/service/$metadata#Employees/$delta',
+                'value':[
+                    {'ID':1,'Name':'Employee1','Friends@odata.delta':[{'Id':1,'Name':'Friend1','Orders@odata.delta':[{'Id':1,'Price': 10},{'Id':2,'Price':20} ]},{'Id':2,'Name':'Friend2'}]},
+                    {'ID':2,'Name':'Employee2','Friends@odata.delta':[{'Id':3,'Name':'Friend3','Orders@odata.delta' :[{'Id':3,'Price': 30}, {'Id':4,'Price': 40} ]},{'Id':4,'Name':'Friend4'}]}
+                ]}";
+
+            var requestForPatch = new HttpRequestMessage(new HttpMethod("PATCH"), requestUri);
+
+            string expectedResponse = "{" +
+                "\"@context\":\"" + this.BaseAddress + "/convention/$metadata#Employees/$delta\"," +
+                "\"value\":[" +
+                "{\"ID\":1,\"Name\":\"Employee1\",\"SkillSet\":[],\"Gender\":\"0\",\"AccessLevel\":\"0\",\"FavoriteSports\":null,\"Friends@delta\":[{\"Id\":1,\"Name\":\"Friend1\",\"Age\":0,\"Orders@delta\":[{\"Id\":1,\"Price\":10},{\"Id\":2,\"Price\":20}]},{\"Id\":2,\"Name\":\"Friend2\",\"Age\":0}]}," +
+                "{\"ID\":2,\"Name\":\"Employee2\",\"SkillSet\":[],\"Gender\":\"0\",\"AccessLevel\":\"0\",\"FavoriteSports\":null,\"Friends@delta\":[{\"Id\":3,\"Name\":\"Friend3\",\"Age\":0,\"Orders@delta\":[{\"Id\":3,\"Price\":30},{\"Id\":4,\"Price\":40}]},{\"Id\":4,\"Name\":\"Friend4\",\"Age\":0}]}]}";
+            StringContent stringContent = new StringContent(content: content, encoding: Encoding.UTF8, mediaType: "application/json");
+            requestForPatch.Content = stringContent;
+
+            // Act & Assert
+            using (HttpResponseMessage response = await this.Client.SendAsync(requestForPatch))
+            {
+                Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+                var json = response.Content.ReadAsStringAsync().Result;
+                Assert.Equal(expectedResponse.ToString().ToLower(), json.ToString().ToLower());
+                Assert.Contains("Employee1", json);
+                Assert.Contains("Employee2", json);
+            }
+        }
+
+        [Fact]
+        public async Task PatchEmployee_WithDeletedAndODataId_IsSerializedSuccessfully()
+        {
+            //Arrange
+            string requestUri = this.BaseAddress + "/convention/Employees";
+
+            var content = @"{
+                '@odata.context':'http://host/service/$metadata#Employees/$delta',
+                'value':[
+                    {'ID':1,'Name':'Employee1','Friends@odata.delta':[{'@odata.removed':{'reason':'changed'},'Id':1}]},
+                    {'ID':2,'Name':'Employee2','Friends@odata.delta':[{'@odata.id':'Friends(1)'}]}
+                ]}";
+
+            string expectedResponse = "{\"@context\":\"" + this.BaseAddress + "/convention/$metadata#Employees/$delta\",\"value\":[{\"ID\":1,\"Name\":\"Employee1\",\"SkillSet\":[],\"Gender\":\"0\",\"AccessLevel\":\"0\",\"FavoriteSports\":null,\"Friends@delta\":[{\"@removed\":{\"reason\":\"changed\"},\"@id\":\"http://host/service/Friends(1)\",\"Id\":1,\"Name\":null,\"Age\":0}]},{\"ID\":2,\"Name\":\"Employee2\",\"SkillSet\":[],\"Gender\":\"0\",\"AccessLevel\":\"0\",\"FavoriteSports\":null,\"Friends@delta\":[{\"Id\":0,\"Name\":null,\"Age\":0}]}]}";
+
+            var requestForUpdate = new HttpRequestMessage(new HttpMethod("PATCH"), requestUri);
+
+            StringContent stringContent = new StringContent(content: content, encoding: Encoding.UTF8, mediaType: "application/json");
+            requestForUpdate.Content = stringContent;
+
+            //Act & Assert
+            using (HttpResponseMessage response = await this.Client.SendAsync(requestForUpdate))
+            {
+                Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+                var json = response.Content.ReadAsStringAsync().Result;
+                Assert.Equal(expectedResponse.ToString().ToLower(), json.ToString().ToLower());
+            }
+        }
+
         [Fact]
         public async Task PatchEmployee_WithUpdates()
         {