SQLite: add JsonValueReaderWriter for Half

src/EFCore.Sqlite.Core/Storage/Internal/SqliteHalfTypeMapping.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Globalization;
+using Microsoft.EntityFrameworkCore.Sqlite.Storage.Json.Internal;
 
 namespace Microsoft.EntityFrameworkCore.Sqlite.Storage.Internal;
 
@@ -30,7 +31,9 @@ public class SqliteHalfTypeMapping : RelationalTypeMapping
     public SqliteHalfTypeMapping(string storeType)
         : base(
             new RelationalTypeMappingParameters(
-                new CoreTypeMappingParameters(typeof(Half)),
+                new CoreTypeMappingParameters(
+                    typeof(Half),
+                    jsonValueReaderWriter: SqliteJsonHalfReaderWriter.Instance),
                 storeType))
     {
     }

src/EFCore.Sqlite.Core/Storage/Json/Internal/SqliteJsonHalfReaderWriter.cs

@@ -0,0 +1,56 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore.Storage.Json;
+
+namespace Microsoft.EntityFrameworkCore.Sqlite.Storage.Json.Internal;
+
+/// <summary>
+///     The Sqlite-specific JsonValueReaderWriter for <see cref="Half" />. Reads and writes JSON number values by converting through
+///     <see langword="float" />, matching the SQLite REAL storage representation.
+/// </summary>
+/// <remarks>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </remarks>
+public sealed class SqliteJsonHalfReaderWriter : JsonValueReaderWriter<Half>
+{
+    private static readonly PropertyInfo InstanceProperty = typeof(SqliteJsonHalfReaderWriter).GetProperty(nameof(Instance))!;
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public static SqliteJsonHalfReaderWriter Instance { get; } = new();
+
+    private SqliteJsonHalfReaderWriter()
+    {
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public override Half FromJsonTyped(ref Utf8JsonReaderManager manager, object? existingObject = null)
+        => (Half)manager.CurrentReader.GetSingle();
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public override void ToJsonTyped(Utf8JsonWriter writer, Half value)
+        => writer.WriteNumberValue((float)value);
+
+    /// <inheritdoc />
+    public override Expression ConstructorExpression
+        => Expression.Property(null, InstanceProperty);
+}

test/EFCore.Sqlite.FunctionalTests/JsonTypesSqliteTest.cs

@@ -184,6 +184,19 @@ public override Task Can_read_write_collection_of_nullable_GUID_JSON_values(stri
         => base.Can_read_write_collection_of_nullable_GUID_JSON_values(
             """{"Prop":["00000000-0000-0000-0000-000000000000",null,"8C44242F-8E3F-4A20-8BE8-98C7C1AADEBD","FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF"]}""");
 
+    [Theory]
+    [InlineData(-65504f, """{"Prop":-65504}""")]
+    [InlineData(65504f, """{"Prop":65504}""")]
+    [InlineData(0f, """{"Prop":0}""")]
+    [InlineData(1.5f, """{"Prop":1.5}""")]
+    public virtual Task Can_read_write_Half_JSON_values(float value, string json)
+        => Can_read_and_write_JSON_value<HalfType, Half>(nameof(HalfType.Half), (Half)value, json);
+
+    protected class HalfType
+    {
+        public Half Half { get; set; }
+    }
+
     public override Task Can_read_write_ulong_enum_JSON_values(EnumU64 value, string json)
         => Can_read_and_write_JSON_value<EnumU64Type, EnumU64>(nameof(EnumU64Type.EnumU64), value, json);