Introduce providing json options as its own construct

src/Elastic.Transport/Components/Serialization/IJsonSerializerOptionsProvider.cs

@@ -0,0 +1,47 @@
+// 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;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Elastic.Transport;
+
+/// <summary>
+/// Provides an instance of <see cref="JsonSerializerOptions"/> to <see cref="SystemTextJsonSerializer"/>
+/// </summary>
+public interface IJsonSerializerOptionsProvider
+{
+	/// <inheritdoc cref="IJsonSerializerOptionsProvider"/>
+	JsonSerializerOptions CreateJsonSerializerOptions();
+}
+/// <summary>
+/// Default implementation of <see cref="IJsonSerializerOptionsProvider"/> specialized in providing more converters and
+/// altering the shared <see cref="JsonSerializerOptions"/> used by <see cref="SystemTextJsonSerializer"/> and its derrived classes
+/// </summary>
+public class TransportSerializerOptionsProvider : IJsonSerializerOptionsProvider
+{
+	private readonly JsonSerializerOptions _options = new();
+
+	/// <inheritdoc cref="IJsonSerializerOptionsProvider"/>
+	public JsonSerializerOptions? CreateJsonSerializerOptions() => _options;
+
+	/// <inheritdoc cref="TransportSerializerOptionsProvider"/>
+	public TransportSerializerOptionsProvider() { }
+
+	/// <inheritdoc cref="TransportSerializerOptionsProvider"/>
+	public TransportSerializerOptionsProvider(IReadOnlyCollection<JsonConverter> bakedIn, IReadOnlyCollection<JsonConverter>? userProvided, Action<JsonSerializerOptions>? optionsAction = null)
+	{
+		foreach (var converter in bakedIn)
+			_options.Converters.Add(converter);
+
+		foreach (var converter in userProvided ?? [])
+			_options.Converters.Add(converter);
+
+		optionsAction?.Invoke(_options);
+
+	}
+}
+

src/Elastic.Transport/Components/Serialization/LowLevelRequestResponseSerializer.cs

@@ -3,66 +3,35 @@
 // See the LICENSE file in the project root for more information
 
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Linq;
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
-using Elastic.Transport.Extensions;
-
 namespace Elastic.Transport;
 
 /// <summary>
 /// Default low level request/response-serializer implementation for <see cref="Serializer"/> which serializes using
 /// the Microsoft <c>System.Text.Json</c> library
 /// </summary>
-internal sealed class LowLevelRequestResponseSerializer :
-	SystemTextJsonSerializer
+internal sealed class LowLevelRequestResponseSerializer : SystemTextJsonSerializer
 {
 	/// <summary>
 	/// Provides a static reusable reference to an instance of <see cref="LowLevelRequestResponseSerializer"/> to promote reuse.
 	/// </summary>
 	internal static readonly LowLevelRequestResponseSerializer Instance = new();
 
-	private IReadOnlyCollection<JsonConverter> AdditionalConverters { get; }
-
-	private IList<JsonConverter> BakedInConverters { get; } = new List<JsonConverter>
-		{
-			new ExceptionConverter(),
-			new ErrorCauseConverter(),
-			new ErrorConverter(),
-			new DynamicDictionaryConverter()
-		};
-
 	/// <inheritdoc cref="LowLevelRequestResponseSerializer"/>>
 	public LowLevelRequestResponseSerializer() : this(null) { }
 
 	/// <summary>
 	/// <inheritdoc cref="LowLevelRequestResponseSerializer"/>>
 	/// </summary>
 	/// <param name="converters">Add more default converters onto <see cref="JsonSerializerOptions"/> being used</param>
-	public LowLevelRequestResponseSerializer(IEnumerable<JsonConverter>? converters) =>
-		AdditionalConverters = converters != null
-			? new ReadOnlyCollection<JsonConverter>(converters.ToList())
-			: EmptyReadOnly<JsonConverter>.Collection;
-
-	/// <summary>
-	/// Creates <see cref="JsonSerializerOptions"/> used for serialization.
-	/// Override on a derived serializer to change serialization.
-	/// </summary>
-	protected override JsonSerializerOptions? CreateJsonSerializerOptions()
-	{
-		var options = new JsonSerializerOptions
-		{
-			DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
-		};
-
-		foreach (var converter in BakedInConverters)
-			options.Converters.Add(converter);
-
-		foreach (var converter in AdditionalConverters)
-			options.Converters.Add(converter);
+	public LowLevelRequestResponseSerializer(IReadOnlyCollection<JsonConverter>? converters)
+		: base(new TransportSerializerOptionsProvider([
+			new ExceptionConverter(),
+			new ErrorCauseConverter(),
+			new ErrorConverter(),
+			new DynamicDictionaryConverter()
+		], converters, options => { options.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull; })) { }
 
-		return options;
-	}
 }

src/Elastic.Transport/Components/Serialization/SystemTextJsonSerializer.cs

@@ -3,8 +3,10 @@
 // See the LICENSE file in the project root for more information
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -14,14 +16,23 @@ namespace Elastic.Transport;
 /// An abstract implementation of a transport <see cref="Serializer"/> which serializes using the Microsoft
 /// <c>System.Text.Json</c> library.
 /// </summary>
-public abstract class SystemTextJsonSerializer :
-	Serializer
+public abstract class SystemTextJsonSerializer : Serializer
 {
-	private readonly SemaphoreSlim _semaphore = new(1);
+	private readonly JsonSerializerOptions? _options;
+	private readonly JsonSerializerOptions? _indentedOptions;
 
-	private bool _initialized;
-	private JsonSerializerOptions? _options;
-	private JsonSerializerOptions? _indentedOptions;
+	/// <summary>
+	/// An abstract implementation of a transport <see cref="Serializer"/> which serializes using the Microsoft
+	/// <c>System.Text.Json</c> library.
+	/// </summary>
+	protected SystemTextJsonSerializer(IJsonSerializerOptionsProvider? provider = null)
+	{
+
+		provider ??= new TransportSerializerOptionsProvider();
+		_options = provider.CreateJsonSerializerOptions();
+		_indentedOptions = provider.CreateJsonSerializerOptions();
+		_indentedOptions.WriteIndented = true;
+	}
 
 	#region Serializer
 
@@ -74,80 +85,14 @@ public override Task SerializeAsync<T>(T data, Stream stream,
 
 	#endregion Serializer
 
-	/// <summary>
-	/// A factory method that can create an instance of <see cref="JsonSerializerOptions"/> that will
-	/// be used when serializing.
-	/// </summary>
-	/// <returns></returns>
-	protected abstract JsonSerializerOptions? CreateJsonSerializerOptions();
-
-	/// <summary>
-	/// A callback function that is invoked after the <see cref="JsonSerializerOptions"/> have been created and the
-	/// serializer got fully initialized.
-	/// </summary>
-	protected virtual void Initialized()
-	{
-	}
-
 	/// <summary>
 	/// Returns the <see cref="JsonSerializerOptions"/> for this serializer, based on the given <paramref name="formatting"/>.
 	/// </summary>
 	/// <param name="formatting">The serialization formatting.</param>
 	/// <returns>The requested <see cref="JsonSerializerOptions"/> or <c>null</c>, if the serializer is not initialized yet.</returns>
-	protected internal JsonSerializerOptions? GetJsonSerializerOptions(SerializationFormatting formatting = SerializationFormatting.None)
-	{
-		Initialize();
-
-		return (formatting is SerializationFormatting.None)
-			? _options
-			: _indentedOptions;
-	}
+	protected internal JsonSerializerOptions? GetJsonSerializerOptions(SerializationFormatting formatting = SerializationFormatting.None) =>
+		formatting is SerializationFormatting.None ? _options : _indentedOptions;
 
-	/// <summary>
-	/// Initializes a serializer instance such that its <see cref="JsonSerializerOptions"/> are populated.
-	/// </summary>
-	private void Initialize()
-	{
-		// Exit early, if already initialized
-		if (_initialized)
-			return;
-
-		_semaphore.Wait();
-
-		try
-		{
-			// Exit early, if the current thread lost the race
-			if (_initialized)
-				return;
-
-			var options = CreateJsonSerializerOptions();
-
-			if (options is null)
-			{
-				_options = new JsonSerializerOptions();
-				_indentedOptions = new JsonSerializerOptions
-				{
-					WriteIndented = true
-				};
-			}
-			else
-			{
-				_options = options;
-				_indentedOptions = new JsonSerializerOptions(options)
-				{
-					WriteIndented = true
-				};
-			}
-
-			_initialized = true;
-
-			Initialized();
-		}
-		finally
-		{
-			_semaphore.Release();
-		}
-	}
 
 	private static bool TryReturnDefault<T>(Stream? stream, out T deserialize)
 	{