fix #1731 contract resolvers were never called

Author: Mpdreamz

Diff for: src/Nest/CommonAbstractions/SerializationBehavior/ElasticContractResolver.cs

@@ -32,7 +32,6 @@ public ElasticContractResolver(IConnectionSettingsValues connectionSettings, ILi
 			this.ConnectionSettings = connectionSettings;
 		}
 
-
 		protected override JsonContract CreateContract(Type objectType)
 		{
 			JsonContract contract = base.CreateContract(objectType);
@@ -44,12 +43,8 @@ protected override JsonContract CreateContract(Type objectType)
 			else if (objectType == typeof(ServerError))
 				contract.Converter = new ServerErrorJsonConverter();
 			else if (objectType == typeof(DateTime) || objectType == typeof(DateTime?))
-				contract.Converter = new IsoDateTimeConverter();
-			else if (!objectType.FullName.StartsWith("Nest.", StringComparison.OrdinalIgnoreCase)) return contract;
-
-			else if (ApplyExactContractJsonAttribute(objectType, contract)) return contract;
-			else if (ApplyContractJsonAttribute(objectType, contract)) return contract;
-
+				contract.Converter = new IsoDateTimeConverter();
+
 			if (this._contractConverters.HasAny())
 			{
 				foreach (var c in this._contractConverters)
@@ -60,7 +55,12 @@ protected override JsonContract CreateContract(Type objectType)
 					contract.Converter = converter;
 					break;
 				}
-			}
+			}
+			if (!objectType.FullName.StartsWith("Nest.", StringComparison.OrdinalIgnoreCase)) return contract;
+
+			else if (ApplyExactContractJsonAttribute(objectType, contract)) return contract;
+			else if (ApplyContractJsonAttribute(objectType, contract)) return contract;
+
 			return contract;
 		}
 

Diff for: src/Tests/ClientConcepts/LowLevel/Connecting.doc.cs

@@ -9,6 +9,7 @@
 using Nest;
 using Newtonsoft.Json;
 using Tests.Framework;
+using Tests.Framework.MockData;
 
 namespace Tests.ClientConcepts.LowLevel
 {
@@ -296,14 +297,21 @@ public MyJsonNetSerializer(IConnectionSettingsValues settings) : base(settings)
 			/** 
 			* Override ModifyJsonSerializerSettings if you need access to `JsonSerializerSettings`
 			*/
-			public int X { get; set; } = 0;
-			protected override void ModifyJsonSerializerSettings(JsonSerializerSettings settings) => ++X;
+			public int CallToModify { get; set; } = 0;
+			protected override void ModifyJsonSerializerSettings(JsonSerializerSettings settings) => ++CallToModify;
 
 			/**
 			* You can inject contract resolved converters by implementing the ContractConverters property
 			* This can be much faster then registering them on JsonSerializerSettings.Converters
 			*/
-			protected override IList<Func<Type, JsonConverter>> ContractConverters => new List<Func<Type, JsonConverter>>();
+			public int CallToContractConverter { get; set; } = 0;
+			protected override IList<Func<Type, JsonConverter>> ContractConverters => new List<Func<Type, JsonConverter>>()
+			{
+				{ t => {
+					CallToContractConverter++;
+					return null;
+				} }
+			};
 
 		}
 
@@ -320,7 +328,10 @@ public void ModifyJsonSerializerSettingsIsCalled()
 			client.RootNodeInfo();
 			client.RootNodeInfo();
 			var serializer = ((IConnectionSettingsValues)settings).Serializer as MyJsonNetSerializer;
-			serializer.X.Should().BeGreaterThan(0);
+			serializer.CallToModify.Should().BeGreaterThan(0);
+
+			serializer.SerializeToString(new Project { });
+			serializer.CallToContractConverter.Should().BeGreaterThan(0);
 		}
 	}
 }