Add WithAlias extensions for CreateIndexRequestDescriptor (#8373)

* Add WithAlias extension methods for CreateIndexRequestDescriptor

* Fix incorrect namespaces in manual code files

* Remove params overloads (for now)

src/Elastic.Clients.Elasticsearch.Shared/Api/Extensions/CreateIndexRequestDescriptorExtensions.cs

@@ -0,0 +1,53 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+#if ELASTICSEARCH_SERVERLESS
+namespace Elastic.Clients.Elasticsearch.Serverless.IndexManagement;
+#else
+namespace Elastic.Clients.Elasticsearch.IndexManagement;
+#endif
+
+public static class CreateIndexRequestDescriptorExtensions
+{
+	/// <summary>
+	/// Add multiple aliases to the index at creation time.
+	/// </summary>
+	/// <param name="descriptor">A descriptor for an index request.</param>
+	/// <param name="aliasName">The name of the alias.</param>
+	/// <returns>The <see cref="CreateIndexRequestDescriptor"/> to allow fluent chaining of calls to configure the indexing request.</returns>
+	public static CreateIndexRequestDescriptor WithAlias(this CreateIndexRequestDescriptor descriptor, string aliasName)
+	{
+#if NET8_0_OR_GREATER
+		ArgumentException.ThrowIfNullOrEmpty(aliasName);
+#else
+		if (string.IsNullOrEmpty(aliasName))
+			throw new ArgumentNullException(nameof(aliasName));
+#endif
+
+		descriptor.Aliases(a => a.Add(aliasName, static _ => { }));
+		return descriptor;
+	}
+
+	/// <summary>
+	/// Adds an alias to the index at creation time.
+	/// </summary>
+	/// <typeparam name="TDocument">The type representing documents stored in this index.</typeparam>
+	/// <param name="descriptor">A fluent descriptor for an index request.</param>
+	/// <param name="aliasName">The name of the alias.</param>
+	/// <returns>The <see cref="CreateIndexRequestDescriptor{TDocument}"/> to allow fluent chaining of calls to configure the indexing request.</returns>
+	public static CreateIndexRequestDescriptor<TDocument> WithAlias<TDocument>(this CreateIndexRequestDescriptor<TDocument> descriptor, string aliasName)
+	{
+#if NET8_0_OR_GREATER
+		ArgumentException.ThrowIfNullOrEmpty(aliasName);
+#else
+		if (string.IsNullOrEmpty(aliasName))
+			throw new ArgumentNullException(nameof(aliasName));
+#endif
+
+		descriptor.Aliases(a => a.Add(aliasName, static _ => { }));
+		return descriptor;
+	}
+}

src/Elastic.Clients.Elasticsearch/_Shared/Api/IndexManagement/ExistsAliasResponse.cs

@@ -5,7 +5,7 @@
 using Elastic.Transport.Products.Elasticsearch;
 
 #if ELASTICSEARCH_SERVERLESS
-namespace Elastic.Clients.Elasticsearch.IndexManagement.Serverless;
+namespace Elastic.Clients.Elasticsearch.Serverless.IndexManagement;
 #else
 namespace Elastic.Clients.Elasticsearch.IndexManagement;
 #endif

src/Elastic.Clients.Elasticsearch/_Shared/Api/IndexManagement/ExistsIndexTemplateResponse.cs

@@ -5,7 +5,7 @@
 using Elastic.Transport.Products.Elasticsearch;
 
 #if ELASTICSEARCH_SERVERLESS
-namespace Elastic.Clients.Elasticsearch.IndexManagement.Serverless;
+namespace Elastic.Clients.Elasticsearch.Serverless.IndexManagement;
 #else
 namespace Elastic.Clients.Elasticsearch.IndexManagement;
 #endif

src/Elastic.Clients.Elasticsearch/_Shared/Api/IndexManagement/ExistsTemplateResponse.cs

@@ -5,7 +5,7 @@
 using Elastic.Transport.Products.Elasticsearch;
 
 #if ELASTICSEARCH_SERVERLESS
-namespace Elastic.Clients.Elasticsearch.IndexManagement.Serverless;
+namespace Elastic.Clients.Elasticsearch.Serverless.IndexManagement;
 #else
 namespace Elastic.Clients.Elasticsearch.IndexManagement;
 #endif