Deserialize caused_by as part of ServerError

Fixes #1845

Author: russcam

src/Elasticsearch.Net/Responses/ServerError.cs

@@ -43,6 +43,7 @@ internal static ServerError Create(IDictionary<string, object> dict, IJsonSerial
 		{
 			object status, error;
 			int statusCode = -1;
+
 			if (dict.TryGetValue("status", out status))
 				statusCode = Convert.ToInt32(status);
 
@@ -82,11 +83,17 @@ public class Error : IRootCause
 		public string ResourceType { get; set; }
 		public string Type { get; set; }
 		public List<RootCause> RootCause { get; set; }
+		public CausedBy CausedBy { get; set; }
 
 		internal static Error Create(IDictionary<string, object> dict, IJsonSerializerStrategy strategy)
 		{
 			var error = new Error();
-			error.FillValues(dict);
+			error.FillValues(dict);
+
+			object causedBy;
+			if (dict.TryGetValue("caused_by", out causedBy))
+				error.CausedBy = (CausedBy) strategy.DeserializeObject(causedBy, typeof(CausedBy));
+
 			object rootCause;
 			if (!dict.TryGetValue("root_cause", out rootCause)) return error;
 
@@ -96,6 +103,26 @@ internal static Error Create(IDictionary<string, object> dict, IJsonSerializerSt
 			return error;
 		}
 
+		public override string ToString() => CausedBy == null
+			? $"Type: {this.Type} Reason: \"{this.Reason}\""
+			: $"Type: {this.Type} Reason: \"{this.Reason}\" CausedBy: \"{this.CausedBy}\"";
+	}
+
+	public class CausedBy
+	{
+		public string Reason { get; set; }
+		public string Type { get; set; }
+
+		internal static CausedBy Create(IDictionary<string, object> dict, IJsonSerializerStrategy strategy)
+		{
+			var causedBy = new CausedBy();
+			object reason;
+			if (dict.TryGetValue("reason", out reason)) causedBy.Reason = Convert.ToString(reason);
+			object type;
+			if (dict.TryGetValue("type", out type)) causedBy.Type = Convert.ToString(type);
+			return causedBy;
+		}
+
 		public override string ToString() => $"Type: {this.Type} Reason: \"{this.Reason}\"";
 	}
 

src/Elasticsearch.Net/Serialization/ElasticsearchNetJsonStrategy.cs

@@ -29,6 +29,11 @@ public override object DeserializeObject(object value, Type type)
 				var dict = base.DeserializeObject(value, typeof(IDictionary<string, object>)) as IDictionary<string, object>;
 				return RootCause.Create(dict, this);
 			}
+			if (type == typeof(CausedBy))
+			{
+				var dict = base.DeserializeObject(value, typeof(IDictionary<string, object>)) as IDictionary<string, object>;
+				return CausedBy.Create(dict, this);
+			}
 			return base.DeserializeObject(value, type);
 		}
 	}

src/Tests/ClientConcepts/ServerError/ServerErrorTests.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices.ComTypes;
+using System.Threading.Tasks;
+using Tests.Framework;
+using Elasticsearch.Net;
+using FluentAssertions;
+using Xunit;
+
+namespace Tests.ClientConcepts.ServerError
+{
+    public class ServerErrorTests : SerializationTestBase
+    {
+		[U]
+	    public void CanDeserializeServerError()
+	    {
+		    var serverErrorJson = @"{
+			   ""error"": {
+				  ""root_cause"": [
+					 {
+						""type"": ""parse_exception"",
+						""reason"": ""failed to parse source for create index""
+					 }
+				  ],
+				  ""type"": ""parse_exception"",
+				  ""reason"": ""failed to parse source for create index"",
+				  ""caused_by"": {
+					 ""type"": ""json_parse_exception"",
+					 ""reason"": ""Unexpected character ('\""' (code 34)): was expecting a colon to separate field name and value\n at [Source: [B@1231dcb3; line: 6, column: 10]""
+				  }
+			   },
+			   ""status"": 400
+			}";
+
+		    var serverError = this.Deserialize<Elasticsearch.Net.ServerError>(serverErrorJson);
+
+		    serverError.Should().NotBeNull();
+			serverError.Status.Should().Be(400);
+
+			serverError.Error.Should().NotBeNull();
+			serverError.Error.RootCause.Count.Should().Be(1);
+			serverError.Error.CausedBy.Should().NotBeNull();
+	    }
+    }
+}

src/Tests/tests.yaml

@@ -1,5 +1,5 @@
 # mode either u (unit test), i (integration test) or m (mixed mode)
-mode: u
+mode: m
 # the elasticsearch version that should be started
 elasticsearch_version: 2.0.1
 # whether we want to forcefully reseed on the node, if you are starting the tests with a node already running