Include Result property on IBulkResponseItem (#3376)

closes #3375

(cherry picked from commit 5bf170d)

Author: russcam

src/Nest/Document/Multiple/Bulk/BulkResponseItem/BulkIndexResponseItem.cs

@@ -10,7 +10,8 @@ public class BulkIndexResponseItem : BulkResponseItemBase
 		public override string Operation { get; internal set; }
 
         /// <summary>
-        /// Null if Percolation was not requested while indexing this doc, otherwise returns the percolator _ids that matched (if any)
+        /// The _ids that matched (if any) for the Percolate API.
+        /// Will be null if the operation is not in response to Percolate API.
         /// </summary>
         [JsonProperty("matches")]
         public IEnumerable<string> Matches { get; internal set; }

src/Nest/Document/Multiple/Bulk/BulkResponseItem/BulkResponseItemBase.cs

@@ -38,6 +38,12 @@ public interface IBulkResponseItem
 		[JsonProperty("_version")]
 		long Version { get; }
 
+		/// <summary>
+		/// The result of the bulk operation
+		/// </summary>
+		[JsonProperty("result")]
+		string Result { get; }
+
 		/// <summary>
 		/// The status of the bulk operation
 		/// </summary>
@@ -86,6 +92,9 @@ public abstract class BulkResponseItemBase : IBulkResponseItem
 		/// <inheritdoc />
 		public long Version { get; internal set; }
 
+		/// <inheritdoc />
+		public string Result { get; internal set; }
+
 		/// <inheritdoc />
 		public int Status { get; internal set; }
 

src/Tests/Tests/Document/Multiple/Bulk/BulkApiTests.cs

@@ -144,6 +144,7 @@ protected override void ExpectResponse(IBulkResponse response)
 				item.Shards.Successful.Should().BeGreaterThan(0);
 				item.SequenceNumber.Should().BeGreaterOrEqualTo(0);
 				item.PrimaryTerm.Should().BeGreaterThan(0);
+				item.Result.Should().NotBeNullOrEmpty();
 			}
 
 			var project1 = this.Client.Source<Project>(Project.Instance.Name, p => p.Index(CallIsolatedValue));