Http and Bolt clients serialize input parameters differently (#423)

* * Introduce property `SerializeNullValues` in `ExecutionConfiguration` class
* Pass new `serializeNullValues` parameter to constructors
* Modify `Neo4jDriverExtensions` to either preserve or skip null values of Objects and Dictionaries depending on congifuration
* Introduce new tests to verify new logic

* Change constructor parameter from `bool? serializeNullValues = null` to `bool serializeNullValues = false`

Author: andrey-kastryukhin

Neo4jClient.Tests/BoltGraphClientTests/BoltGraphClientTests.cs

@@ -219,6 +219,79 @@ public async Task SerializesGuidsProperlyWhenAutoGeneratingParams()
             var query = cfq.Query;
             query.ToNeo4jDriverParameters(bgc).IsEqualTo(expectedParameters).Should().BeTrue();
         }
+        
+        [Fact]
+        // Issue from https://github.com/DotNet4Neo4j/Neo4jClient/issues/419
+        public async Task SerializesObjectProperlyWithoutNullPropertiesDefaultConfiguration()
+        {
+            var expectedParameters = new Dictionary<string, object>
+            {
+                {"param", new Dictionary<string, object> {{"Param1", 1}}}
+            };
+
+            await SerializesObjectProperlyWitDifferentStrategies(
+                expectedParameters,
+                client => {}
+            );
+        }
+        
+        [Fact]
+        // Issue from https://github.com/DotNet4Neo4j/Neo4jClient/issues/419
+        public async Task SerializesObjectProperlyWithNullProperties()
+        {
+            var expectedParameters = new Dictionary<string, object>
+            {
+                {"param", new Dictionary<string, object> {{"Param1", 1}, {"Param2", null}}}
+            };
+
+            await SerializesObjectProperlyWitDifferentStrategies(
+                expectedParameters,
+                client => client.ExecutionConfiguration.SerializeNullValues = true
+            );
+        }
+        
+        [Fact]
+        // Issue from https://github.com/DotNet4Neo4j/Neo4jClient/issues/419
+        public async Task SerializesObjectProperlyWithoutNullProperties()
+        {
+            var expectedParameters = new Dictionary<string, object>
+            {
+                { "param", new Dictionary<string, object> { { "Param1", 1 } } }
+            };
+            
+            await SerializesObjectProperlyWitDifferentStrategies(
+                expectedParameters,
+                client => client.ExecutionConfiguration.SerializeNullValues = false
+            );
+        }
+
+        private static async Task SerializesObjectProperlyWitDifferentStrategies(IDictionary<string, object> expectedParameters, Action<BoltGraphClient> setupClient)
+        {
+            var mockSession = new Mock<IAsyncSession>();
+            mockSession.Setup(s => s.RunAsync("CALL dbms.components()"))
+                .Returns(Task.FromResult<IResultCursor>(new ServerInfo()));
+
+            var mockDriver = new Mock<IDriver>();
+            mockDriver.Setup(d => d.AsyncSession(It.IsAny<Action<SessionConfigBuilder>>())).Returns(mockSession.Object);
+
+            var bgc = new BoltGraphClient(mockDriver.Object);
+            await bgc.ConnectAsync();
+
+            setupClient(bgc);
+
+            var obj = new
+            {
+                Param1 = 1,
+                Param2 = (object)null
+            };
+
+            var cfq = bgc.Cypher.Create("MATCH (node:FakeNode) SET node += $param").WithParam("param", obj);
+
+            var query = cfq.Query;
+            var t = query.ToNeo4jDriverParameters(bgc);
+            t.IsEqualTo(expectedParameters).Should().BeTrue();
+        }
+
         //
         // [Fact]
         // public void RootNode_ThrowsInvalidOperationException()

Neo4jClient.Tests/TestUtilities.cs

@@ -21,10 +21,10 @@ public static bool IsEqualTo<TKey, TValue>(this IDictionary<TKey, TValue> d1, ID
 
                 var v1 = d1[d1Key];
                 var v2 = d2[d1Key];
-                if (v1.GetType() == typeof(Dictionary<TKey, TValue>))
+                if (v1?.GetType() == typeof(Dictionary<TKey, TValue>))
                     return IsEqualTo((IDictionary<TKey, TValue>)v1, (IDictionary<TKey, TValue>)v2);
 
-                if (!d1[d1Key].Equals(d2[d1Key]))
+                if(!Equals(d1[d1Key], d2[d1Key]))
                     return false;
             }
             return true;

Neo4jClient/BoltGraphClient.cs

@@ -70,7 +70,7 @@ public class BoltGraphClient : IBoltGraphClient, IRawGraphClient, ITransactional
         /// <param name="username">The username to connect to Neo4j with.</param>
         /// <param name="password">The password to connect to Neo4j with.</param>
         /// <param name="realm">The realm to connect to Neo4j with.</param>
-        public BoltGraphClient(Uri uri, IEnumerable<Uri> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null)
+        public BoltGraphClient(Uri uri, IEnumerable<Uri> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null, bool serializeNullValues = false)
         {
             var localUris = uris?.ToList();
             if (localUris != null && localUris.Any())
@@ -104,30 +104,31 @@ public BoltGraphClient(Uri uri, IEnumerable<Uri> uris, string username = null, s
                 JsonConverters = JsonConverters,
                 Username = username,
                 Password = password,
-                Realm = realm
+                Realm = realm,
+                SerializeNullValues = serializeNullValues
             };
 
             transactionManager = new BoltTransactionManager(this);
         }
 
-        public BoltGraphClient(Uri uri, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null)
-            : this(uri, null, username, password, realm, encryptionLevel)
+        public BoltGraphClient(Uri uri, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null, bool serializeNullValues = false)
+            : this(uri, null, username, password, realm, encryptionLevel, serializeNullValues)
         { }
 
-        public BoltGraphClient(IEnumerable<string> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null)
-            : this(new Uri("neo4j://virtual.neo4j.uri"), uris?.Select(UriCreator.From).ToList(), username, password, realm, encryptionLevel)
+        public BoltGraphClient(IEnumerable<string> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null, bool serializeNullValues = false)
+            : this(new Uri("neo4j://virtual.neo4j.uri"), uris?.Select(UriCreator.From).ToList(), username, password, realm, encryptionLevel, serializeNullValues)
         { }
 
-        public BoltGraphClient(string uri, IEnumerable<string> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null)
-        : this(new Uri(uri), uris?.Select(UriCreator.From).ToList(), username, password, realm, encryptionLevel)
+        public BoltGraphClient(string uri, IEnumerable<string> uris, string username = null, string password = null, string realm = null, EncryptionLevel? encryptionLevel = null, bool serializeNullValues = false)
+        : this(new Uri(uri), uris?.Select(UriCreator.From).ToList(), username, password, realm, encryptionLevel, serializeNullValues)
         {}
 
-        public BoltGraphClient(string uri, string username = null, string password= null, string realm = null, EncryptionLevel? encryptionLevel = null)
-            : this(new Uri(uri), username, password, realm, encryptionLevel)
+        public BoltGraphClient(string uri, string username = null, string password= null, string realm = null, EncryptionLevel? encryptionLevel = null, bool serializeNullValues = false)
+            : this(new Uri(uri), username, password, realm, encryptionLevel, serializeNullValues)
         { }
 
         public BoltGraphClient(IDriver driver)
-            : this(new Uri("neo4j://Neo4j-Driver-Does-Not-Supply-This/"), null, null, null, null)
+            : this(new Uri("neo4j://Neo4j-Driver-Does-Not-Supply-This/"), null, null, null, null, false)
         {
             Driver = driver;
         }

Neo4jClient/Execution/ExecutionConfiguration.cs

@@ -22,5 +22,6 @@ public ExecutionConfiguration()
         public Guid ResourceManagerId { get; set; }
         public string Realm { get; set; }
         public EncryptionLevel? EncryptionLevel { get; set; }
+        public bool SerializeNullValues { get; set; }
     }
 }

Neo4jClient/Neo4jDriverExtensions.cs

@@ -8,7 +8,6 @@
 using Neo4j.Driver;
 using Neo4jClient.Cypher;
 using Neo4jClient.Serialization;
-using Neo4jClient.Transactions;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 
@@ -100,9 +99,20 @@ private static object Serialize(object value, IList<JsonConverter> converters, I
 
         private static object SerializeObject(Type type, object value, IList<JsonConverter> converters, IGraphClient gc)
         {
-            return type.GetProperties(BindingFlags.Instance | BindingFlags.Public)
-                .Where(pi => !(pi.GetIndexParameters().Any() || pi.IsDefined(typeof(JsonIgnoreAttribute)) || pi.IsDefined(typeof(Neo4jIgnoreAttribute))))
-                .ToDictionary(pi => GetPropertyName(pi.Name, gc, type), pi => Serialize(pi.GetValue(value), converters, gc, pi.CustomAttributes));
+            var serialized = new Dictionary<string, object>();
+            foreach (var propertyInfo in type.GetProperties(BindingFlags.Instance | BindingFlags.Public)
+                .Where(pi => !(pi.GetIndexParameters().Any() || pi.IsDefined(typeof(JsonIgnoreAttribute)) || pi.IsDefined(typeof(Neo4jIgnoreAttribute)))))
+            {
+                var propertyName = GetPropertyName(propertyInfo.Name, gc, type);
+                var propertyValue = propertyInfo.GetValue(value);
+
+                if (propertyValue != null || gc.ExecutionConfiguration.SerializeNullValues)
+                {
+                    serialized.Add(propertyName, Serialize(propertyValue, converters, gc, propertyInfo.CustomAttributes));
+                }
+            }
+            
+            return serialized;
         }
 
         private static string GetPropertyName(string argName, IGraphClient gc, Type type)
@@ -181,7 +191,10 @@ private static object SerializeDictionary(Type type, object value, IList<JsonCon
                 string key = item.Key;
                 object entry = item.Value;
 
-                serialized[key] = Serialize(entry, converters, gc);
+                if (entry != null || gc.ExecutionConfiguration.SerializeNullValues)
+                {
+                    serialized[key] = Serialize(entry, converters, gc);
+                }
             }
 
             return serialized;