update based on review comments

test/FunctionalTests/Tests/DataServices/UnitTests/Client.TDD.Tests/Tests/BulkUpdateE2ETests.cs

@@ -10,6 +10,7 @@
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Xml;
 using AstoriaUnitTests.Tests;
@@ -125,7 +126,7 @@ public void CallingBulkUpdateRequest_WithNullArguments_ShouldThrowAnException()
         }
 
         [Fact]
-        public async Task CallingBulkUpdateAsync_WithNullArguments_ShouldThrowAnExceptionAsync()
+        public async Task CallingBulkUpdateAsync_WithNullArguments_ShouldThrowAnException()
         {
             await Assert.ThrowsAsync<ArgumentException>(async () => await this.context.BulkUpdateAsync<Person>(null));
         }
@@ -171,6 +172,29 @@ public void BulkUpdateAnEntry_WithOneLevelOfNesting_ReturnsOne_OperationResponse
             Assert.Equal(1001, returnedCar.ID);
         }
 
+        [Fact]
+        public async Task BulkUpdateAsync_ShouldThrowExceptions_RaisedDuringSeriliazation()
+        {
+            var expectedResponse = "{\"@context\":\"http://localhost:8000/$metadata#Persons/$delta\",\"value\":[{\"ID\":100,\"Name\":\"Bing\"}]}";
+
+            SetupContextWithRequestPipelineForSaving(
+                this.context,
+                expectedResponse);
+
+            var person = new Person
+            {
+                ID = 100,
+                Name = "Bing",
+            };
+
+            this.context.AttachTo("Persons", person);
+
+            var entitydesc = this.context.Entities[0] as EntityDescriptor;
+            entitydesc.Entity = null;
+
+            await Assert.ThrowsAsync<NullReferenceException>(() => this.context.BulkUpdateAsync(person));
+        }
+
         [Fact]
         public void HandleResponse_Of_AnInvalidResponse_ThrowsException()
         {
@@ -404,57 +428,6 @@ public async Task BulkUpdateAsyncTwoTopLevelObjects_WithTheSameNestedObject_Dese
             Assert.Equal(carTargetEntity, car2TargetEntity);
         }
 
-        [Fact]
-        public async Task NullTopLevelObjects_ShouldThrowException()
-        {
-            var expectedResponse = "{\"@context\":\"http://localhost:8000/$metadata#Persons/$delta\",\"value\":[{\"ID\":100,\"Name\":\"Bing\",\"Cars@delta\":[{\"@id\":\"http://localhost:8000/Cars(1001)\"}]},{\"ID\":200,\"Name\":\"Edge\",\"Cars@delta\":[{\"@id\":\"http://localhost:8000/Cars(1001)\"}]}]}";
-
-            SetupContextWithRequestPipelineForSaving(
-                this.context,
-                expectedResponse);
-
-            var person = new Person
-            {
-                ID = 100,
-                Name = "Bing",
-            };
-
-            var person2 = new Person
-            {
-                ID = 200,
-                Name = "Edge"
-            };
-
-            var car = new Car
-            {
-                ID = 1002,
-                Name = "CarA"
-            };
-
-            this.context.AttachTo("Persons", person);
-            this.context.AttachTo("Persons", person2);
-            this.context.AttachTo("Cars", car);
-
-            this.context.AddLink(person, "Cars", car);
-            this.context.AddLink(person2, "Cars", car);
-
-            DataServiceResponse response = await this.context.BulkUpdateAsync(person, person2);
-
-            var personOperationResponse = response.First() as ChangeOperationResponse;
-            var person1 = (personOperationResponse.Descriptor as EntityDescriptor).Entity as Person;
-            var personcarOperationResponse = personOperationResponse.NestedResponses.FirstOrDefault() as ChangeOperationResponse;
-            var carTargetEntity = (personcarOperationResponse.Descriptor as LinkDescriptor).Target as Car;
-            var person2OperationResponse = response.Last() as ChangeOperationResponse;
-            var person2Response = (person2OperationResponse.Descriptor as EntityDescriptor).Entity as Person;
-            var person2carOperationResponse = personOperationResponse.NestedResponses.FirstOrDefault() as ChangeOperationResponse;
-            var car2TargetEntity = (person2carOperationResponse.Descriptor as LinkDescriptor).Target as Car;
-
-            Assert.Equal(2, response.Count());
-            Assert.Equal("Bing", person1.Name);
-            Assert.Equal("Edge", person2Response.Name);
-            Assert.Equal(carTargetEntity, car2TargetEntity);
-        }
-
         [Fact]
         public void TwoTopLevelObjects_WithNestedProperties_UpdatedSuccessfully()
         {