Fix tests and BOM

src/Elastic.Transport/Components/Pipeline/RequestData.cs

@@ -40,9 +40,6 @@ public RequestData(ITransportConfiguration global, IRequestConfiguration? local
 		ProxyPassword = global.ProxyPassword;
 		DisableAutomaticProxyDetection = global.DisableAutomaticProxyDetection;
 		UserAgent = global.UserAgent;
-		ResponseBuilders = local?.ResponseBuilders ?? global.ResponseBuilders;
-		ProductResponseBuilders = global.ProductRegistration.ResponseBuilders;
-
 		KeepAliveInterval = (int)(global.KeepAliveInterval?.TotalMilliseconds ?? 2000);
 		KeepAliveTime = (int)(global.KeepAliveTime?.TotalMilliseconds ?? 2000);
 		RunAs = local?.RunAs ?? global.RunAs;
@@ -89,8 +86,36 @@ public RequestData(ITransportConfiguration global, IRequestConfiguration? local
 			Headers ??= [];
 			Headers.Add(OpaqueIdHeader, local.OpaqueId);
 		}
-	}
 
+		// If there are builders set at the transport level and on the request config, we combine them,
+		// prioritising the request config response builders as most specific.
+		if (local is not null && local.ResponseBuilders.Count > 0 && global.ResponseBuilders.Count > 0)
+		{
+			var builders = new IResponseBuilder[local.ResponseBuilders.Count + global.ResponseBuilders.Count];
+
+			var counter = 0;
+			foreach (var builder in local.ResponseBuilders)
+			{
+				builders[counter++] = builder;
+			}
+			foreach (var builder in global.ResponseBuilders)
+			{
+				builders[counter++] = builder;
+			}
+
+			ResponseBuilders = builders;
+		}
+		else if (local is not null && local.ResponseBuilders.Count > 0)
+		{
+			ResponseBuilders = local.ResponseBuilders;
+		}
+		else
+		{
+			ResponseBuilders = global.ResponseBuilders;
+		}
+
+		ProductResponseBuilders = global.ProductRegistration.ResponseBuilders;
+	}
 
 	/// <inheritdoc cref="ITransportConfiguration.MemoryStreamFactory"/>
 	public MemoryStreamFactory MemoryStreamFactory { get; }

src/Elastic.Transport/Configuration/IRequestConfiguration.cs

@@ -1,4 +1,4 @@
-// Licensed to Elasticsearch B.V under one or more agreements.
+// 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
 

src/Elastic.Transport/Configuration/RequestConfiguration.cs

@@ -64,6 +64,7 @@ public RequestConfiguration(IRequestConfiguration config)
 		ResponseHeadersToParse = (config.ResponseHeadersToParse is null) ? null : new HeadersList(config.ResponseHeadersToParse);
 		ParseAllHeaders = config.ParseAllHeaders;
 		RequestMetaData = config.RequestMetaData;
+		ResponseBuilders = config.ResponseBuilders;
 	}
 
 	/// <inheritdoc />

src/Elastic.Transport/Configuration/RequestConfigurationDescriptor.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Linq;
 using System.Security.Cryptography.X509Certificates;
 
 using Elastic.Transport.Extensions;
@@ -49,6 +50,7 @@ public RequestConfigurationDescriptor(IRequestConfiguration? config)
 		_responseHeadersToParse = (config.ResponseHeadersToParse is null) ? null : new HeadersList(config.ResponseHeadersToParse);
 		_parseAllHeaders = config.ParseAllHeaders;
 		_requestMetaData = config.RequestMetaData;
+		_responseBuilders = [.. config.ResponseBuilders];
 	}
 
 	private string? _accept;
@@ -336,5 +338,5 @@ public RequestConfigurationDescriptor ResponseBuilder(IResponseBuilder responseB
 
 	RequestMetaData? IRequestConfiguration.RequestMetaData => _requestMetaData;
 
-	IReadOnlyCollection<IResponseBuilder> IRequestConfiguration.ResponseBuilders => _responseBuilders;
+	IReadOnlyCollection<IResponseBuilder> IRequestConfiguration.ResponseBuilders => _responseBuilders ?? [];
 }

tests/Elastic.Transport.Tests/Configuration/RequestConfigurationTests.cs

@@ -38,7 +38,7 @@ public void SameDefaults()
 	public void CopiesAllProperties()
 	{
 		var autoFaker = new AutoFaker<RequestConfiguration>();
-		autoFaker.RuleFor(x => x.ClientCertificates, f => new X509CertificateCollection());
+		autoFaker.RuleFor(x => x.ClientCertificates, f => []);
 
 		var config = autoFaker.Generate();
 		config.Accept.Should().NotBeEmpty();