From 5773b3a85b695982c9ebc096b64838f6b0ed53c6 Mon Sep 17 00:00:00 2001
From: Joe Feser <joseph.feser@gmail.com>
Date: Mon, 29 Jul 2024 19:07:25 -0500
Subject: [PATCH] feat(): add .net6 and .net8 to core project and get it to
 compile #680

---
 .../Utf8Json/Formatters/DateTimeFormatter.cs  | 47 +++++++++++++++++++
 .../Utf8Json/Resolvers/BuiltinResolver.cs     |  7 +++
 2 files changed, 54 insertions(+)

diff --git a/src/OpenSearch.Net/Utf8Json/Formatters/DateTimeFormatter.cs b/src/OpenSearch.Net/Utf8Json/Formatters/DateTimeFormatter.cs
index 534eaa9155..f746f58b1f 100644
--- a/src/OpenSearch.Net/Utf8Json/Formatters/DateTimeFormatter.cs
+++ b/src/OpenSearch.Net/Utf8Json/Formatters/DateTimeFormatter.cs
@@ -948,4 +948,51 @@ public TimeSpan Deserialize(ref JsonReader reader, IJsonFormatterResolver format
 			throw new InvalidOperationException("invalid TimeSpan format. value:" + StringEncoding.UTF8.GetString(str.Array, str.Offset, str.Count));
 		}
 	}
+
+#if NET6_0_OR_GREATER
+	internal sealed class DateOnlyFormatter : IJsonFormatter<DateOnly>
+	{
+		public static readonly IJsonFormatter<DateOnly> Default = new DateOnlyFormatter();
+
+		private readonly string _formatString;
+
+		public DateOnlyFormatter() => _formatString = "o"; //we are choosing the ISO 8601 format as the default
+
+		public DateOnlyFormatter(string formatString) => _formatString = formatString;
+
+		public void Serialize(ref JsonWriter writer, DateOnly value, IJsonFormatterResolver formatterResolver) =>
+			writer.WriteString(value.ToString(_formatString));
+
+		public DateOnly Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
+		{
+			var str = reader.ReadString();
+			return _formatString == null || _formatString == "o"
+				? DateOnly.Parse(str, CultureInfo.InvariantCulture)
+				: DateOnly.ParseExact(str, _formatString, CultureInfo.InvariantCulture);
+		}
+	}
+
+	internal sealed class TimeOnlyFormatter : IJsonFormatter<TimeOnly>
+	{
+		public static readonly IJsonFormatter<TimeOnly> Default = new TimeOnlyFormatter();
+
+		private readonly string _formatString;
+
+		public TimeOnlyFormatter() => _formatString = "o"; //if we do not use o, you loose the milliseconds and microseconds
+
+		public TimeOnlyFormatter(string formatString) => _formatString = formatString;
+
+		public void Serialize(ref JsonWriter writer, TimeOnly value, IJsonFormatterResolver formatterResolver) =>
+			writer.WriteString(value.ToString(_formatString));
+
+		public TimeOnly Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
+		{
+			var str = reader.ReadString();
+			return _formatString == null || _formatString == "o"
+				? TimeOnly.Parse(str, CultureInfo.InvariantCulture)
+				: TimeOnly.ParseExact(str, _formatString, CultureInfo.InvariantCulture);
+		}
+	}
+#endif
+
 }
diff --git a/src/OpenSearch.Net/Utf8Json/Resolvers/BuiltinResolver.cs b/src/OpenSearch.Net/Utf8Json/Resolvers/BuiltinResolver.cs
index 5d79a7eb36..bf1b682205 100644
--- a/src/OpenSearch.Net/Utf8Json/Resolvers/BuiltinResolver.cs
+++ b/src/OpenSearch.Net/Utf8Json/Resolvers/BuiltinResolver.cs
@@ -121,6 +121,13 @@ internal static class BuiltinResolverGetFormatterHelper
 				{typeof(TimeSpan?), new StaticNullableFormatter<TimeSpan>(ISO8601TimeSpanFormatter.Default)},
 				{typeof(DateTimeOffset?),new StaticNullableFormatter<DateTimeOffset>(ISO8601DateTimeOffsetFormatter.Default)},
 
+#if NET6_0_OR_GREATER
+				{typeof(DateOnly), DateOnlyFormatter.Default},
+				{typeof(TimeOnly), TimeOnlyFormatter.Default},
+				{typeof(DateOnly?), new StaticNullableFormatter<DateOnly>(DateOnlyFormatter.Default)},
+				{typeof(TimeOnly?), new StaticNullableFormatter<TimeOnly>(TimeOnlyFormatter.Default)},
+#endif
+
 				{typeof(string), NullableStringFormatter.Default},
 				{typeof(char), CharFormatter.Default},
 				{typeof(char?), NullableCharFormatter.Default},