System.Text.Json: Add TimeSpanConverter

src/libraries/System.Text.Json/ref/System.Text.Json.cs

@@ -887,6 +887,7 @@ public static partial class JsonMetadataServices
         public static System.Text.Json.Serialization.JsonConverter<sbyte> SByteConverter { get { throw null; } }
         public static System.Text.Json.Serialization.JsonConverter<float> SingleConverter { get { throw null; } }
         public static System.Text.Json.Serialization.JsonConverter<string> StringConverter { get { throw null; } }
+        public static System.Text.Json.Serialization.JsonConverter<System.TimeSpan> TimeSpanConverter { get { throw null; } }
         [System.CLSCompliantAttribute(false)]
         public static System.Text.Json.Serialization.JsonConverter<ushort> UInt16Converter { get { throw null; } }
         [System.CLSCompliantAttribute(false)]

src/libraries/System.Text.Json/src/Resources/Strings.resx

@@ -318,6 +318,9 @@
   <data name="FormatDateTimeOffset" xml:space="preserve">
     <value>The JSON value is not in a supported DateTimeOffset format.</value>
   </data>
+  <data name="FormatTimeSpan" xml:space="preserve">
+    <value>The JSON value is not in a supported TimeSpan format.</value>
+  </data>
   <data name="FormatGuid" xml:space="preserve">
     <value>The JSON value is not in a supported Guid format.</value>
   </data>

src/libraries/System.Text.Json/src/System.Text.Json.csproj

@@ -165,6 +165,7 @@
     <Compile Include="System\Text\Json\Serialization\Converters\Value\SByteConverter.cs" />
     <Compile Include="System\Text\Json\Serialization\Converters\Value\SingleConverter.cs" />
     <Compile Include="System\Text\Json\Serialization\Converters\Value\StringConverter.cs" />
+    <Compile Include="System\Text\Json\Serialization\Converters\Value\TimeSpanConverter.cs" />
     <Compile Include="System\Text\Json\Serialization\Converters\Value\UInt16Converter.cs" />
     <Compile Include="System\Text\Json\Serialization\Converters\Value\UInt32Converter.cs" />
     <Compile Include="System\Text\Json\Serialization\Converters\Value\UInt64Converter.cs" />

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeSpanConverter.cs

@@ -0,0 +1,81 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Buffers;
+using System.Buffers.Text;
+using System.Diagnostics;
+
+namespace System.Text.Json.Serialization.Converters
+{
+    internal sealed class TimeSpanConverter : JsonConverter<TimeSpan>
+    {
+        private const int MinimumTimeSpanFormatLength = 7; // h:mm:ss
+        private const int MaximumTimeSpanFormatLength = 26; // -dddddddd.hh:mm:ss.fffffff
+
+        public override TimeSpan Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            if (reader.TokenType != JsonTokenType.String)
+            {
+                throw ThrowHelper.GetInvalidOperationException_ExpectedString(reader.TokenType);
+            }
+
+            ReadOnlySpan<byte> source = stackalloc byte[0];
+
+            if (reader.HasValueSequence)
+            {
+                ReadOnlySequence<byte> valueSequence = reader.ValueSequence;
+                long sequenceLength = valueSequence.Length;
+
+                if (!JsonHelpers.IsInRangeInclusive(sequenceLength, MinimumTimeSpanFormatLength, MaximumTimeSpanFormatLength))
+                {
+                    throw ThrowHelper.GetFormatException();
+                }
+
+                Span<byte> stackSpan = stackalloc byte[(int)sequenceLength];
+
+                valueSequence.CopyTo(stackSpan);
+                source = stackSpan;
+            }
+            else
+            {
+                source = reader.ValueSpan;
+
+                if (!JsonHelpers.IsInRangeInclusive(source.Length, MinimumTimeSpanFormatLength, MaximumTimeSpanFormatLength))
+                {
+                    throw ThrowHelper.GetFormatException();
+                }
+            }
+
+            bool result = Utf8Parser.TryParse(source, out TimeSpan tmpValue, out int bytesConsumed, 'c');
+
+            // Note: Utf8Parser.TryParse will return true for invalid input so
+            // long as it starts with an integer. Example: "2021-06-18" or
+            // "1$$$$$$$$$$". We need to check bytesConsumed to know if the
+            // entire source was actually valid.
+
+            if (result && source.Length == bytesConsumed)
+            {
+                return tmpValue;
+            }
+
+            result = Utf8Parser.TryParse(source, out tmpValue, out bytesConsumed, 'g');
+
+            if (result && source.Length == bytesConsumed)
+            {
+                return tmpValue;
+            }
+
+            throw ThrowHelper.GetFormatException();
+        }
+
+        public override void Write(Utf8JsonWriter writer, TimeSpan value, JsonSerializerOptions options)
+        {
+            Span<byte> output = stackalloc byte[MaximumTimeSpanFormatLength];
+
+            bool result = Utf8Formatter.TryFormat(value, output, out int bytesWritten, 'c');
+            Debug.Assert(result);
+
+            writer.WriteStringValue(output.Slice(0, bytesWritten));
+        }
+    }
+}

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs

@@ -49,7 +49,7 @@ private void RootBuiltInConverters()
 
         private static Dictionary<Type, JsonConverter> GetDefaultSimpleConverters()
         {
-            const int NumberOfSimpleConverters = 23;
+            const int NumberOfSimpleConverters = 24;
             var converters = new Dictionary<Type, JsonConverter>(NumberOfSimpleConverters);
 
             // Use a dictionary for simple converters.
@@ -72,6 +72,7 @@ private void RootBuiltInConverters()
             Add(JsonMetadataServices.SByteConverter);
             Add(JsonMetadataServices.SingleConverter);
             Add(JsonMetadataServices.StringConverter);
+            Add(JsonMetadataServices.TimeSpanConverter);
             Add(JsonMetadataServices.UInt16Converter);
             Add(JsonMetadataServices.UInt32Converter);
             Add(JsonMetadataServices.UInt64Converter);

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonMetadataServices.Converters.cs

@@ -110,6 +110,12 @@ public static partial class JsonMetadataServices
         public static JsonConverter<string> StringConverter => s_stringConverter ??= new StringConverter();
         private static JsonConverter<string>? s_stringConverter;
 
+        /// <summary>
+        /// Returns a <see cref="JsonConverter{T}"/> instance that converts <see cref="TimeSpan"/> values.
+        /// </summary>
+        public static JsonConverter<TimeSpan> TimeSpanConverter => s_timeSpanConverter ??= new TimeSpanConverter();
+        private static JsonConverter<TimeSpan>? s_timeSpanConverter;
+
         /// <summary>
         /// Returns a <see cref="JsonConverter{T}"/> instance that converts <see cref="ushort"/> values.
         /// </summary>

src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.cs

@@ -636,6 +636,9 @@ public static FormatException GetFormatException(DataType dateType)
                 case DataType.DateTimeOffset:
                     message = SR.FormatDateTimeOffset;
                     break;
+                case DataType.TimeSpan:
+                    message = SR.FormatTimeSpan;
+                    break;
                 case DataType.Base64String:
                     message = SR.CannotDecodeInvalidBase64;
                     break;
@@ -723,6 +726,7 @@ internal enum DataType
         Boolean,
         DateTime,
         DateTimeOffset,
+        TimeSpan,
         Base64String,
         Guid,
     }

src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.ReadTests.cs

@@ -3,6 +3,7 @@
 
 using System.Globalization;
 using System.Runtime.CompilerServices;
+using Newtonsoft.Json;
 using Xunit;
 
 namespace System.Text.Json.Serialization.Tests
@@ -80,6 +81,7 @@ public static void ReadPrimitivesFail()
 
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<DateTime>("\"abc\""));
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<DateTimeOffset>("\"abc\""));
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<TimeSpan>("\"abc\""));
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<Guid>("\"abc\""));
 
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<byte>("\"abc\""));
@@ -118,6 +120,7 @@ public static void ReadPrimitivesFail()
         [InlineData(typeof(sbyte))]
         [InlineData(typeof(float))]
         [InlineData(typeof(string))]
+        [InlineData(typeof(TimeSpan))]
         [InlineData(typeof(ushort))]
         [InlineData(typeof(uint))]
         [InlineData(typeof(ulong))]
@@ -303,6 +306,9 @@ public static void ValueFail()
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<DateTimeOffset>(unexpectedString));
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<DateTimeOffset?>(unexpectedString));
 
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<TimeSpan>(unexpectedString));
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<TimeSpan?>(unexpectedString));
+
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<string>("1"));
 
             Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<char>("1"));
@@ -442,5 +448,64 @@ private static void DeserializeLongJsonString(int stringLength)
             string str = JsonSerializer.Deserialize<string>(json);
             Assert.True(json.AsSpan(1, json.Length - 2).SequenceEqual(str.AsSpan()));
         }
+
+        [Theory]
+        [InlineData("23:59:59")]
+        [InlineData("23:59:59.9", "23:59:59.9000000")]
+        [InlineData("23:59:59.9999999")]
+        [InlineData("1:00:00", "01:00:00")] // 'g' Format
+        [InlineData("1:2:00:00", "1.02:00:00")] // 'g' Format
+        [InlineData("9999999.23:59:59.9999999")]
+        [InlineData("-9999999.23:59:59.9999999")]
+        [InlineData("10675199.02:48:05.4775807")] // TimeSpan.MaxValue
+        [InlineData("-10675199.02:48:05.4775808")] // TimeSpan.MinValue
+        public static void TimeSpan_Read_Success(string json, string? actual = null)
+        {
+            TimeSpan value = JsonSerializer.Deserialize<TimeSpan>($"\"{json}\"");
+
+            Assert.Equal(TimeSpan.Parse(actual ?? json), value);
+            Assert.Equal(value, JsonConvert.DeserializeObject<TimeSpan>($"\"{json}\""));
+        }
+
+        [Fact]
+        public static void TimeSpan_Read_KnownDifferences()
+        {
+            string value = "24:00:00";
+
+            // 24:00:00 should be invalid because hours can only be up to 23.
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<TimeSpan>($"\"{value}\""));
+
+            TimeSpan expectedValue = TimeSpan.Parse("24.00:00:00");
+
+            // TimeSpan.Parse has a quirk where it treats 24:00:00 as 24.00:00:00.
+            Assert.Equal(expectedValue, TimeSpan.Parse(value));
+
+            // Newtonsoft uses TimeSpan.Parse so it is subject to the quirk.
+            Assert.Equal(expectedValue, JsonConvert.DeserializeObject<TimeSpan>($"\"{value}\""));
+        }
+
+        [Theory]
+        [InlineData("24:00:00")]
+        [InlineData("00:60:00")]
+        [InlineData("00:00:60")]
+        [InlineData("00:00:00.00000009")]
+        [InlineData("900000000.00:00:00")]
+        [InlineData("+00:00:00")]
+        [InlineData("2021-06-18")]
+        [InlineData("1$")]
+        [InlineData("10675199.02:48:05.4775808")] // TimeSpan.MaxValue + 1
+        [InlineData("-10675199.02:48:05.4775809")] // TimeSpan.MinValue - 1
+        [InlineData("1234", false)]
+        [InlineData("{}", false)]
+        [InlineData("[]", false)]
+        [InlineData("true", false)]
+        [InlineData("null", false)]
+        public static void TimeSpan_Read_Failure(string json, bool addQuotes = true)
+        {
+            if (addQuotes)
+                json = $"\"{json}\"";
+
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<TimeSpan>(json));
+        }
     }
 }

src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.WriteTests.cs

@@ -112,5 +112,24 @@ public static void WritePrimitives()
                 Assert.Equal(@"""1.2.3.4""", JsonSerializer.Serialize(version));
             }
         }
+
+        [Theory]
+        [InlineData("1:59:59", "01:59:59")]
+        [InlineData("23:59:59")]
+        [InlineData("23:59:59.9", "23:59:59.9000000")]
+        [InlineData("23:59:59.9999999")]
+        [InlineData("1.23:59:59")]
+        [InlineData("9999999.23:59:59.9999999")]
+        [InlineData("-9999999.23:59:59.9999999")]
+        [InlineData("10675199.02:48:05.4775807")] // TimeSpan.MaxValue
+        [InlineData("-10675199.02:48:05.4775808")] // TimeSpan.MinValue
+        public static void TimeSpan_Write_Success(string value, string? expectedValue = null)
+        {
+            TimeSpan ts = TimeSpan.Parse(value);
+            string json = JsonSerializer.Serialize(ts);
+
+            Assert.Equal($"\"{expectedValue ?? value}\"", json);
+            Assert.Equal(json, JsonConvert.SerializeObject(ts));
+        }
     }
 }