Fix parsing of DateHistogramBucket key (#131)

Signed-off-by: Thomas Farr <[email protected]>

CHANGELOG.md

@@ -17,6 +17,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Removed `net461` target from internal packages ([#128](https://github.com/opensearch-project/opensearch-net/pull/128))
 
 ### Fixed
+- Fixed parsing of date histogram buckets ([#131](https://github.com/opensearch-project/opensearch-net/pull/131))
 
 ### Security
 - CVE-2019-0820: Removed transitive dependencies on `System.Text.RegularExpressions` from internal packages; **Client Not Impacted** ([#137](https://github.com/opensearch-project/opensearch-net/pull/137))

src/OpenSearch.Client/Aggregations/AggregateFormatter.cs

@@ -843,7 +843,7 @@ private IBucket GetDateHistogramBucket(ref JsonReader reader, IJsonFormatterReso
 			reader.ReadNext(); // ,
 			reader.ReadNext(); // "key"
 			reader.ReadNext(); // :
-			var key = reader.ReadInt64();
+			var key = reader.ReadDouble();
 			reader.ReadNext(); // ,
 			reader.ReadNext(); // "doc_count"
 			reader.ReadNext(); // :

tests/Tests.Reproduce/GitHubIssue130.cs

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: Apache-2.0
+*
+* The OpenSearch Contributors require contributions made to
+* this file be licensed under the Apache-2.0 license or a
+* compatible open source license.
+*/
+
+using System;
+using System.Linq;
+using System.Threading;
+using OpenSearch.Client;
+using OpenSearch.OpenSearch.Xunit.XunitPlumbing;
+using Tests.Core.Extensions;
+using Tests.Core.ManagedOpenSearch.Clusters;
+using Tests.Domain;
+
+namespace Tests.Reproduce
+{
+	/// <summary>
+	/// Parsing histogram interval failed: <a href="https://github.com/opensearch-project/opensearch-net/issues/130">Issue #130</a>
+	/// </summary>
+	///
+	public class GitHubIssue130 : IClusterFixture<WritableCluster>
+	{
+		private readonly WritableCluster _cluster;
+
+		public GitHubIssue130(WritableCluster cluster) => _cluster = cluster;
+
+		[I] public void CanDeserializeDateHistogramBucket()
+		{
+			var response = _cluster.Client.Search<Project>(c => c
+				.Size(0)
+				.Query(q => q.MatchAll())
+				.Aggregations(a => a.Histogram("aggregation_ranges", r => r
+						.Field(f => f.LastActivity)
+						.Interval(5000)
+					)
+				)
+			);
+
+			response.ShouldBeValid();
+		}
+	}
+}