[OData] Allow serialization of complex type properties that have a null value

5 files changed, 40 insertions, 15 deletions

diff --git a/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataCollectionSerializer.cs b/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataCollectionSerializer.cs
index c18fd953..587cef71 100644
--- a/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataCollectionSerializer.cs
+++ b/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataCollectionSerializer.cs
@@ -69,7 +69,11 @@ namespace System.Web.Http.OData.Formatter.Serialization
             }
 
             IEnumerable enumerable = graph as IEnumerable;
-            if (enumerable != null)
+            if (enumerable == null)
+            {
+                return new ODataProperty() { Name = elementName, Value = null };
+            }
+            else
             {
                 ArrayList valueCollection = new ArrayList();
 
@@ -90,8 +94,6 @@ namespace System.Web.Http.OData.Formatter.Serialization
                 // Also, note that TypeName is an optional property for ODataCollectionValue
                 return new ODataProperty() { Name = elementName, Value = new ODataCollectionValue { Items = valueCollection } };
             }
-
-            return null;
         }
     }
 }
diff --git a/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataComplexTypeSerializer.cs b/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataComplexTypeSerializer.cs
index 7013c961..0b0f5df0 100644
--- a/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataComplexTypeSerializer.cs
+++ b/src/System.Web.Http.OData/OData/Formatter/Serialization/ODataComplexTypeSerializer.cs
@@ -47,11 +47,13 @@ namespace System.Web.Http.OData.Formatter.Serialization
                 throw Error.ArgumentNull("writeContext");
             }
 
-            List<ODataProperty> propertyCollection = null;
-
-            if (graph != null)
+            if (graph == null)
             {
-                propertyCollection = new List<ODataProperty>();
+                return new ODataProperty() { Name = elementName, Value = null };
+            }
+            else
+            {
+                List<ODataProperty> propertyCollection = new List<ODataProperty>();
                 foreach (IEdmProperty property in _edmComplexType.ComplexDefinition().Properties())
                 {
                     IEdmTypeReference propertyType = property.Type;
@@ -66,10 +68,6 @@ namespace System.Web.Http.OData.Formatter.Serialization
 
                     propertyCollection.Add(propertySerializer.CreateProperty(propertyValue, property.Name, writeContext));
                 }
-            }
-
-            if (propertyCollection != null)
-            {
                 return new ODataProperty()
                 {
                     Name = elementName,
@@ -80,10 +78,6 @@ namespace System.Web.Http.OData.Formatter.Serialization
                     }
                 };
             }
-            else
-            {
-                return null;
-            }
         }
     }
 }
diff --git a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataCollectionSerializerTests.cs b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataCollectionSerializerTests.cs
index f78652be..d03c3f4d 100644
--- a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataCollectionSerializerTests.cs
+++ b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataCollectionSerializerTests.cs
@@ -53,5 +53,14 @@ namespace System.Web.Http.OData.Formatter.Serialization
 
             Assert.Equal(elements, new int[] { 1, 2, 3 });
         }
+
+        [Fact]
+        public void CreateProperty_ReturnsODataProperty_ForNullValue()
+        {
+            var property = _serializer.CreateProperty(null, "TestCollection", new ODataSerializerContext());
+
+            Assert.NotNull(property);
+            Assert.Null(property.Value);
+        }
     }
 }
diff --git a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataComplexTypeSerializerTests.cs b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataComplexTypeSerializerTests.cs
index 78174117..b9d87118 100644
--- a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataComplexTypeSerializerTests.cs
+++ b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataComplexTypeSerializerTests.cs
@@ -52,5 +52,14 @@ namespace System.Web.Http.OData.Formatter.Serialization
                     Tuple.Create("Country", "United States"),
                     Tuple.Create("ZipCode","98052") });
         }
+
+        [Fact]
+        public void CreateProperty_ReturnsODataProperty_ForNullValue()
+        {
+            var property = _serializer.CreateProperty(null, "ComplexElement", new ODataSerializerContext());
+
+            Assert.NotNull(property);
+            Assert.Null(property.Value);
+        }
     }
 }
diff --git a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataPrimitiveSerializerTests.cs b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataPrimitiveSerializerTests.cs
index 2601a2f3..20b74ebd 100644
--- a/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataPrimitiveSerializerTests.cs
+++ b/test/System.Web.Http.OData.Test/OData/Formatter/Serialization/ODataPrimitiveSerializerTests.cs
@@ -112,6 +112,17 @@ namespace System.Web.Http.OData.Formatter.Serialization
             Assert.Equal(odataProperty.Value, 20);
         }
 
+        [Fact]
+        public void CreateProperty_ReturnsODataProperty_ForNullValue()
+        {
+            IEdmPrimitiveTypeReference edmPrimitiveType = EdmLibHelpers.GetEdmPrimitiveTypeReferenceOrNull(typeof(string));
+            var serializer = new ODataPrimitiveSerializer(edmPrimitiveType);
+            var property = serializer.CreateProperty(null, "elementName", new ODataSerializerContext());
+
+            Assert.NotNull(property);
+            Assert.Null(property.Value);
+        }
+
         [Theory]
         [PropertyData("EdmPrimitiveData")]
         [PropertyData("NonEdmPrimitiveData")]