Fix #4289 low level client index http method generation wrong (#4290)

* Fix #4289 low level client index http method generation wrong

We used to always send POST which is not right either but the server
accepted it. Now that we have a new format and transform to the old
format in the interim we only picked up PUT for all which is not correct
for index operations without an id.

* add unit tests

(cherry picked from commit 02d4076)

Author: Mpdreamz

src/CodeGeneration/ApiGenerator/Domain/Specification/ApiEndpoint.cs

@@ -133,6 +133,10 @@ public IReadOnlyCollection<LowLevelClientMethod> LowLevelClientMethods
 					var methodName = CsharpNames.PerPathMethodName(path.Path);
 					var parts = new List<UrlPart>(path.Parts);
 					var mapsApiArgumentHints = parts.Select(p => p.Name).ToList();
+					// TODO This is hack until we stop transforming the new spec format into the old
+					if (Name == "index" && !mapsApiArgumentHints.Contains("id"))
+						httpMethod = "POST";
+					else if (Name == "index") httpMethod = PreferredHttpMethod;
 
 					if (Body != null)
 					{

src/Elasticsearch.Net/Api/RequestParameters/RequestParameters.CrossClusterReplication.cs

@@ -79,6 +79,7 @@ public class GetAutoFollowPatternRequestParameters : RequestParameters<GetAutoFo
 	public class PauseAutoFollowPatternRequestParameters : RequestParameters<PauseAutoFollowPatternRequestParameters>
 	{
 		public override HttpMethod DefaultHttpMethod => HttpMethod.POST;
+		public override bool SupportsBody => false;
 	}
 
 	///<summary>Request options for PauseFollowIndex <para>https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-post-pause-follow.html</para></summary>
@@ -99,6 +100,7 @@ public class CreateAutoFollowPatternRequestParameters : RequestParameters<Create
 	public class ResumeAutoFollowPatternRequestParameters : RequestParameters<ResumeAutoFollowPatternRequestParameters>
 	{
 		public override HttpMethod DefaultHttpMethod => HttpMethod.POST;
+		public override bool SupportsBody => false;
 	}
 
 	///<summary>Request options for ResumeFollowIndex <para>https://www.elastic.co/guide/en/elasticsearch/reference/current/ccr-post-resume-follow.html</para></summary>

src/Elasticsearch.Net/ElasticLowLevelClient.NoNamespace.cs

@@ -516,19 +516,19 @@ public TResponse Index<TResponse>(string index, string id, PostData body, IndexR
 		[MapsApi("index", "index, id, body")]
 		public Task<TResponse> IndexAsync<TResponse>(string index, string id, PostData body, IndexRequestParameters requestParameters = null, CancellationToken ctx = default)
 			where TResponse : class, IElasticsearchResponse, new() => DoRequestAsync<TResponse>(PUT, Url($"{index:index}/_doc/{id:id}"), ctx, body, RequestParams(requestParameters));
-		///<summary>PUT on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
+		///<summary>POST on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
 		///<param name = "index">The name of the index</param>
 		///<param name = "body">The document</param>
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>
 		public TResponse Index<TResponse>(string index, PostData body, IndexRequestParameters requestParameters = null)
-			where TResponse : class, IElasticsearchResponse, new() => DoRequest<TResponse>(PUT, Url($"{index:index}/_doc"), body, RequestParams(requestParameters));
-		///<summary>PUT on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
+			where TResponse : class, IElasticsearchResponse, new() => DoRequest<TResponse>(POST, Url($"{index:index}/_doc"), body, RequestParams(requestParameters));
+		///<summary>POST on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
 		///<param name = "index">The name of the index</param>
 		///<param name = "body">The document</param>
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>
 		[MapsApi("index", "index, body")]
 		public Task<TResponse> IndexAsync<TResponse>(string index, PostData body, IndexRequestParameters requestParameters = null, CancellationToken ctx = default)
-			where TResponse : class, IElasticsearchResponse, new() => DoRequestAsync<TResponse>(PUT, Url($"{index:index}/_doc"), ctx, body, RequestParams(requestParameters));
+			where TResponse : class, IElasticsearchResponse, new() => DoRequestAsync<TResponse>(POST, Url($"{index:index}/_doc"), ctx, body, RequestParams(requestParameters));
 		///<summary>GET on / <para>https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html</para></summary>
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>
 		public TResponse RootNodeInfo<TResponse>(RootNodeInfoRequestParameters requestParameters = null)

src/Elasticsearch.Net/IElasticLowLevelClient.Generated.cs

@@ -417,13 +417,13 @@ TResponse Index<TResponse>(string index, string id, PostData body, IndexRequestP
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>
 		Task<TResponse> IndexAsync<TResponse>(string index, string id, PostData body, IndexRequestParameters requestParameters = null, CancellationToken ctx = default)
 			where TResponse : class, IElasticsearchResponse, new();
-		///<summary>PUT on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
+		///<summary>POST on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
 		///<param name = "index">The name of the index</param>
 		///<param name = "body">The document</param>
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>
 		TResponse Index<TResponse>(string index, PostData body, IndexRequestParameters requestParameters = null)
 			where TResponse : class, IElasticsearchResponse, new();
-		///<summary>PUT on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
+		///<summary>POST on /{index}/_doc <para>https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-index_.html</para></summary>
 		///<param name = "index">The name of the index</param>
 		///<param name = "body">The document</param>
 		///<param name = "requestParameters">Request specific configuration such as querystring parameters &amp; request specific connection settings.</param>

src/Tests/Tests/Document/Single/Index/IndexUrlTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using Elastic.Xunit.XunitPlumbing;
+using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
 using Tests.Domain;
@@ -42,6 +43,20 @@ await PUT("/project/_doc/NEST")
 				.RequestAsync(c => c.IndexAsync(new IndexRequest<Project>(project)));
 		}
 
+		[U] public async Task LowLevelUrls()
+		{
+			var project = new Project { Name = "NEST" };
+
+			await POST("/index/_doc")
+				.LowLevel(c => c.Index<VoidResponse>("index", PostData.Empty))
+				.LowLevelAsync(c => c.IndexAsync<VoidResponse>("index", PostData.Empty));
+
+			await PUT("/index/_doc/id")
+				.LowLevel(c => c.Index<VoidResponse>("index", "id", PostData.Empty))
+				.LowLevelAsync(c => c.IndexAsync<VoidResponse>("index", "id", PostData.Empty));
+
+		}
+
 		[U] public async Task CanIndexUrlIds()
 		{
 			var id = "http://my.local/id?qwe=2";

src/Tests/Tests/Framework/EndpointTests/UrlTests.cs

@@ -71,6 +71,11 @@ public UrlTester LowLevel(Func<IElasticLowLevelClient, IApiCallDetails> call)
 			var callDetails = call(Client.LowLevel);
 			return Assert("lowlevel", callDetails);
 		}
+		public async Task<UrlTester> LowLevelAsync(Func<IElasticLowLevelClient, Task<VoidResponse>> call)
+		{
+			var callDetails = await call(Client.LowLevel);
+			return Assert("lowlevel async", callDetails);
+		}
 
 		private UrlTester WhenCalling<TResponse>(Func<IElasticClient, TResponse> call, string typeOfCall)
 			where TResponse : IResponse