Merge branch 'sklirg-fix/4029-enum-get-type-throwing'

(cherry picked from commit 7d974ac)

Author: russcam

src/Elasticsearch.Net/Utf8Json/Formatters/EnumFormatter.cs

@@ -151,11 +151,11 @@ public static object GetDeserializeDelegate(Type type, out bool isBoxed)
 	// can inherit for set optimize manual serialize/deserialize func.
 	internal class EnumFormatter<T> : IJsonFormatter<T>, IObjectPropertyNameFormatter<T>
 	{
-		readonly static ByteArrayStringHashTable<T> nameValueMapping;
-		readonly static Dictionary<T, string> valueNameMapping;
+		private static readonly ByteArrayStringHashTable<T> nameValueMapping;
+		private static readonly Dictionary<T, string> valueNameMapping;
 
-		readonly static JsonSerializeAction<T> defaultSerializeByUnderlyingValue;
-		readonly static JsonDeserializeFunc<T> defaultDeserializeByUnderlyingValue;
+		private static readonly JsonSerializeAction<T> defaultSerializeByUnderlyingValue;
+		private static readonly JsonDeserializeFunc<T> defaultDeserializeByUnderlyingValue;
 
 		static EnumFormatter()
 		{
@@ -166,7 +166,7 @@ static EnumFormatter()
 			foreach (var item in type.GetFields().Where(fi => fi.FieldType == type))
 			{
 				var value = item.GetValue(null);
-				var name = Enum.GetName(type, value);
+				var name = item.Name;
 				var dataMember = item.GetCustomAttributes(typeof(DataMemberAttribute), true)
 					.OfType<DataMemberAttribute>()
 					.FirstOrDefault();

src/Tests/Tests/CodeStandards/Serialization/Enums.cs

@@ -1,12 +1,18 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Net;
 using System.Reflection;
 using System.Runtime.Serialization;
+using System.Text;
 using Elastic.Xunit.XunitPlumbing;
 using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
+using Tests.Core.Serialization;
+using Tests.QueryDsl.Geo.Shape;
+using Tests.XPack.MachineLearning;
 
 namespace Tests.CodeStandards.Serialization
 {
@@ -34,5 +40,48 @@ public void EnumsWithEnumMembersShouldBeMarkedWithStringEnumAttribute()
 			}
 			notMarkedStringEnum.Should().BeEmpty();
 		}
+
+		[U]
+		public void CanSerializeEnumsWithMultipleMembersMappedToSameValue()
+		{
+			var document = new EnumDocument
+			{
+				Int = HttpStatusCode.Moved,
+				String = AnotherEnum.Value1
+			};
+
+			var client = new ElasticClient();
+
+			var json = client.RequestResponseSerializer.SerializeToString(document);
+
+			// "Value2" will be written for both "Value1" and "Value2" because the underlying integer value
+			// for both is the same, and "Value2" field member is listed after "Value1", overwriting
+			// the value mapping.
+			//
+			// Json.Net behaves similarly, except the first string mapped for a value
+			// is not overwritten i.e. "Value1" will be written for both "Value1" and "Value2"
+			json.Should().Be("{\"int\":301,\"string\":\"Value2\"}");
+
+			EnumDocument deserializedDocument;
+			using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(json)))
+				deserializedDocument = client.RequestResponseSerializer.Deserialize<EnumDocument>(stream);
+
+			deserializedDocument.Int.Should().Be(document.Int);
+			deserializedDocument.String.Should().Be(document.String);
+		}
+
+		private class EnumDocument
+	    {
+			public HttpStatusCode Int { get;set;}
+
+			public AnotherEnum String { get; set; }
+		}
+
+		[StringEnum]
+		public enum AnotherEnum : int
+		{
+			Value1 = 1,
+			Value2 = 1
+		}
 	}
 }