fix #3544 JsonNetSerializer now also implements IPropertyMappingProvi… (#3545)

* fix #3544 JsonNetSerializer now also implements IPropertyMappingProvider making it easier to bootstrap

* extended unit test for property resolving with custom source serializer with a Field resolution assertion for completeness sake

Author: Mpdreamz

src/Nest/CommonAbstractions/ConnectionSettings/ConnectionSettingsBase.cs

@@ -88,7 +88,8 @@ IPropertyMappingProvider propertyMappingProvider
 			var defaultSerializer = new InternalSerializer(this);
 			_sourceSerializer = sourceSerializerFactory?.Invoke(defaultSerializer, this) ?? defaultSerializer;
 			UseThisRequestResponseSerializer = defaultSerializer;
-			_propertyMappingProvider = propertyMappingProvider ?? new PropertyMappingProvider();
+			var serializerAsMappingProvider = _sourceSerializer as IPropertyMappingProvider;
+			_propertyMappingProvider = propertyMappingProvider ?? serializerAsMappingProvider ?? new PropertyMappingProvider();
 
 			_defaultTypeNameInferrer = t => !_defaultTypeName.IsNullOrEmpty() ? _defaultTypeName : t.Name.ToLowerInvariant();
 			_defaultFieldNameInferrer = p => p.ToCamelCase();

src/Serializers/Nest.JsonNetSerializer/ConnectionSettingsAwareSerializerBase.PropertyMappingProvider.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Concurrent;
+using System.IO;
+using System.Reflection;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Elasticsearch.Net;
+using Newtonsoft.Json;
+
+namespace Nest.JsonNetSerializer
+{
+	public abstract partial class ConnectionSettingsAwareSerializerBase : IPropertyMappingProvider
+	{
+		protected readonly ConcurrentDictionary<string, IPropertyMapping> Properties = new ConcurrentDictionary<string, IPropertyMapping>();
+
+		public IPropertyMapping CreatePropertyMapping(MemberInfo memberInfo)
+		{
+			var memberInfoString = $"{memberInfo.DeclaringType?.FullName}.{memberInfo.Name}";
+			if (Properties.TryGetValue(memberInfoString, out var mapping)) return mapping;
+			mapping = FromAttributes(memberInfo);
+
+			Properties.TryAdd(memberInfoString, mapping);
+			return mapping;
+		}
+
+		private static IPropertyMapping FromAttributes(MemberInfo memberInfo)
+		{
+			var jsonProperty = memberInfo.GetCustomAttribute<JsonPropertyAttribute>(true);
+			var dataMemberProperty = memberInfo.GetCustomAttribute<DataMemberAttribute>(true);
+			var propertyName = memberInfo.GetCustomAttribute<PropertyNameAttribute>(true);
+			var ignore = memberInfo.GetCustomAttribute<IgnoreAttribute>(true);
+			var jsonIgnore = memberInfo.GetCustomAttribute<JsonIgnoreAttribute>(true);
+			if (jsonProperty == null && ignore == null && propertyName == null && dataMemberProperty == null && jsonIgnore == null) return null;
+
+			return new PropertyMapping
+				{ Name = propertyName?.Name ?? jsonProperty?.PropertyName ?? dataMemberProperty?.Name, Ignore = ignore != null || jsonIgnore != null };
+		}
+	}
+}

src/Tests/Tests/ClientConcepts/HighLevel/Inference/FieldInference.doc.cs

@@ -8,6 +8,7 @@
 using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
+using Nest.JsonNetSerializer;
 using Newtonsoft.Json;
 using Tests.Core.Client;
 using Tests.Core.Client.Settings;
@@ -563,5 +564,42 @@ public void CodeBasedConfigurationInherits()
 			});
 
 		}
+
+
+		public class SourceModel
+		{
+			[PropertyName("gexo")]
+			public GeoModel Geo { get; set; }
+		}
+
+		public class GeoModel
+		{
+			[JsonProperty("country_iso_code")]
+			public string CountryIsoCode { get; set; }
+		}
+
+		/// this tests runs both during development as wel as during canary builds which reference
+		/// all the artifacts as nuget packages instead of project references
+		[U]
+		public void JsonPropertyIsPickedWhenSerializerIsInternalized()
+		{
+			var usingSettings = WithConnectionSettings(s => s)
+				.WithSourceSerializer(JsonNetSerializer.Default);
+
+			usingSettings.Expect("gexo").ForField(Field<SourceModel>(p=>p.Geo));
+			usingSettings.Expect("country_iso_code").ForField(Field<GeoModel>(p=>p.CountryIsoCode));
+			usingSettings.Expect(new []
+			{
+				"country_iso_code",
+			}).AsPropertiesOf(new GeoModel { CountryIsoCode = "nl" });
+			usingSettings.Expect(new []
+			{
+				"gexo",
+			}).AsPropertiesOf(new SourceModel { Geo = new GeoModel { CountryIsoCode = "nl" } });
+
+			usingSettings.Expect("gexo.country_iso_code").ForField(Field<SourceModel>(p=>p.Geo.CountryIsoCode));
+		}
+
+
 	}
 }