[Backport 1.x] Allow passing "auto" as the slices parameter

CHANGELOG.md

@@ -9,6 +9,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Fixed `HttpConnection.ConvertHttpMethod` to support `Patch` method ([#489](https://github.com/opensearch-project/opensearch-net/pull/489))
 - Fixed `IEnumerable<int?>` property mapping. ([#503](https://github.com/opensearch-project/opensearch-net/pull/503))
 - Fixed `ConnectionConfiguration.DefaultMemoryStreamFactory` actually used as default. ([#552](https://github.com/opensearch-project/opensearch-net/pull/552))
+- Fixed passing `"auto"` to the `slices` parameter ([#553](https://github.com/opensearch-project/opensearch-net/pull/553))
 
 ### Dependencies
 - Bumps `NSwag.Core.Yaml` from 13.19.0 to 14.0.3

src/OpenSearch.Client/Descriptors.NoNamespace.cs

@@ -357,7 +357,7 @@ public DeleteByQueryDescriptor<TDocument> Index<TOther>()
 		///<summary>Search operation type</summary>
 		public DeleteByQueryDescriptor<TDocument> SearchType(SearchType? searchtype) => Qs("search_type", searchtype);
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks.</summary>
-		public DeleteByQueryDescriptor<TDocument> Slices(long? slices) => Qs("slices", slices);
+		public DeleteByQueryDescriptor<TDocument> Slices(Slices slices) => Qs("slices", slices);
 		///<summary>A comma-separated list of &lt;field&gt;:&lt;direction&gt; pairs</summary>
 		public DeleteByQueryDescriptor<TDocument> Sort(params string[] sort) => Qs("sort", sort);
 		///<summary>Whether the _source should be included in the response.</summary>
@@ -1171,7 +1171,7 @@ public partial class ReindexOnServerDescriptor : RequestDescriptorBase<ReindexOn
 		///<summary>Control how long to keep the search context alive</summary>
 		public ReindexOnServerDescriptor Scroll(Time scroll) => Qs("scroll", scroll);
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks. Can be set to `auto`.</summary>
-		public ReindexOnServerDescriptor Slices(long? slices) => Qs("slices", slices);
+		public ReindexOnServerDescriptor Slices(Slices slices) => Qs("slices", slices);
 		///<summary>Time each individual bulk request should wait for shards that are unavailable.</summary>
 		public ReindexOnServerDescriptor Timeout(Time timeout) => Qs("timeout", timeout);
 		///<summary>Sets the number of shard copies that must be active before proceeding with the reindex operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)</summary>
@@ -1651,7 +1651,7 @@ public UpdateByQueryDescriptor<TDocument> Index<TOther>()
 		///<summary>Search operation type</summary>
 		public UpdateByQueryDescriptor<TDocument> SearchType(SearchType? searchtype) => Qs("search_type", searchtype);
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks. Can be set to `auto`.</summary>
-		public UpdateByQueryDescriptor<TDocument> Slices(long? slices) => Qs("slices", slices);
+		public UpdateByQueryDescriptor<TDocument> Slices(Slices slices) => Qs("slices", slices);
 		///<summary>A comma-separated list of &lt;field&gt;:&lt;direction&gt; pairs</summary>
 		public UpdateByQueryDescriptor<TDocument> Sort(params string[] sort) => Qs("sort", sort);
 		///<summary>Whether the _source should be included in the response.</summary>

src/OpenSearch.Client/Document/Multiple/Slices/Slices.cs

@@ -0,0 +1,29 @@
+/* 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 OpenSearch.Net.Utf8Json;
+
+namespace OpenSearch.Client;
+
+[JsonFormatter(typeof(SlicesFormatter))]
+public class Slices : Union<long, string>
+{
+	public Slices(long value) : base(value) { }
+
+	public Slices(string value) : base(value) { }
+
+	public static implicit operator Slices(long value) => new(value);
+	public static implicit operator Slices(long? value) => value is { } v ? new Slices(v) : null;
+	public static implicit operator Slices(string value) => value is { } v ? new Slices(value) : null;
+
+	public override string ToString() => Tag switch
+	{
+		0 => Item1.ToString(),
+		1 => Item2,
+		_ => null
+	};
+}

src/OpenSearch.Client/Document/Multiple/Slices/SlicesFormatter.cs

@@ -0,0 +1,31 @@
+/* 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 OpenSearch.Net.Utf8Json;
+
+namespace OpenSearch.Client;
+
+internal class SlicesFormatter : IJsonFormatter<Slices>
+{
+	private static readonly UnionFormatter<long, string> UnionFormatter = new();
+
+	public void Serialize(ref JsonWriter writer, Slices value, IJsonFormatterResolver formatterResolver) =>
+		UnionFormatter.Serialize(ref writer, value, formatterResolver);
+
+	public Slices Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
+	{
+		var union = UnionFormatter.Deserialize(ref reader, formatterResolver);
+		if (union == null) return null;
+
+		return union.Tag switch
+		{
+			0 => new Slices(union.Item1),
+			1 => new Slices(union.Item2),
+			_ => null
+		};
+	}
+}

src/OpenSearch.Client/Requests.NoNamespace.cs

@@ -771,9 +771,9 @@ public SearchType? SearchType
 		}
 
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks.</summary>
-		public long? Slices
+		public Slices Slices
 		{
-			get => Q<long? >("slices");
+			get => Q<Slices>("slices");
 			set => Q("slices", value);
 		}
 
@@ -2477,9 +2477,9 @@ public Time Scroll
 		}
 
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks. Can be set to `auto`.</summary>
-		public long? Slices
+		public Slices Slices
 		{
-			get => Q<long? >("slices");
+			get => Q<Slices>("slices");
 			set => Q("slices", value);
 		}
 
@@ -3605,9 +3605,9 @@ public SearchType? SearchType
 		}
 
 		///<summary>The number of slices this task should be divided into. Defaults to 1, meaning the task isn't sliced into subtasks. Can be set to `auto`.</summary>
-		public long? Slices
+		public Slices Slices
 		{
-			get => Q<long? >("slices");
+			get => Q<Slices>("slices");
 			set => Q("slices", value);
 		}
 

src/OpenSearch.Client/Search/TrackTotalHits/TrackTotalHits.cs

@@ -0,0 +1,31 @@
+/* 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 OpenSearch.Net.Utf8Json;
+
+namespace OpenSearch.Client;
+
+[JsonFormatter(typeof(TrackTotalHitsFormatter))]
+public class TrackTotalHits : Union<bool, long>
+{
+	public TrackTotalHits(bool item) : base(item) { }
+
+	public TrackTotalHits(long item) : base(item) { }
+
+	public static implicit operator TrackTotalHits(bool trackTotalHits) => new(trackTotalHits);
+	public static implicit operator TrackTotalHits(bool? trackTotalHits) => trackTotalHits is {} b ? new TrackTotalHits(b) : null;
+
+	public static implicit operator TrackTotalHits(long trackTotalHitsUpTo) => new(trackTotalHitsUpTo);
+	public static implicit operator TrackTotalHits(long? trackTotalHitsUpTo) => trackTotalHitsUpTo is {} l ? new TrackTotalHits(l) : null;
+
+	public override string ToString() => Tag switch
+	{
+		0 => Item1.ToString(),
+		1 => Item2.ToString(),
+		_ => null
+	};
+}

src/OpenSearch.Client/Search/TrackTotalHits/TrackTotalHitsFormatter.cs

@@ -0,0 +1,30 @@
+/* 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 OpenSearch.Net.Utf8Json;
+
+namespace OpenSearch.Client;
+
+internal class TrackTotalHitsFormatter : IJsonFormatter<TrackTotalHits>
+{
+	private static readonly UnionFormatter<bool, long> UnionFormatter = new();
+
+	public void Serialize(ref JsonWriter writer, TrackTotalHits value, IJsonFormatterResolver formatterResolver) =>
+		UnionFormatter.Serialize(ref writer, value, formatterResolver);
+
+	public TrackTotalHits Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
+	{
+		var union = UnionFormatter.Deserialize(ref reader, formatterResolver);
+		if (union == null) return null;
+		return union.Tag switch
+		{
+			0 => new TrackTotalHits(union.Item1),
+			1 => new TrackTotalHits(union.Item2),
+			_ => null
+		};
+	}
+}