Implement Write method on SourceConfigConverter

src/Elastic.Clients.Elasticsearch/Types/SourceConfig.cs

@@ -60,5 +60,15 @@ internal class SourceConfigConverter : JsonConverter<SourceConfig>
 		return null;
 	}
 
-	public override void Write(Utf8JsonWriter writer, SourceConfig value, JsonSerializerOptions options) => throw new NotImplementedException();
+	public override void Write(Utf8JsonWriter writer, SourceConfig value, JsonSerializerOptions options)
+	{
+		if (value.HasBoolValue)
+		{
+			writer.WriteBooleanValue(value.Item1);
+		}
+		else
+		{
+			JsonSerializer.Serialize(writer, value.Item2, options);
+		}
+	}
 }

tests/Tests/Search/Search/SearchRequestSerialization.cs

@@ -0,0 +1,34 @@
+// 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.Collections.Generic;
+using System.Threading.Tasks;
+using Elastic.Clients.Elasticsearch.Core.Search;
+using Tests.Serialization;
+using VerifyXunit;
+
+namespace Tests.Search.Search;
+
+[UsesVerify]
+public class SearchRequestSerialization : SerializerTestBase
+{
+	[U]
+	public async Task SearchRequestWithSourceProperty_SerializesCorrectly()
+	{
+		var descriptor = new SearchRequestDescriptor("test")
+			.Source(new SourceConfig(false));
+
+		var json = await SerializeAndGetJsonStringAsync(descriptor);
+
+		await Verifier.VerifyJson(json);
+
+		var searchRequest = new SearchRequest("test")
+		{
+			Source = new SourceConfig(false),
+		};
+
+		var objectJson = await SerializeAndGetJsonStringAsync(searchRequest);
+		objectJson.Should().Be(json);
+	}
+}

tests/Tests/_VerifySnapshots/SearchRequestSerialization.SearchRequestWithSourceProperty_SerializesCorrectly.verified.txt

@@ -0,0 +1,3 @@
+{
+  _source: false
+}