PolymorphicObjectConverter crashes with a type that converts to a primitive #7178
Description
Description
When trying to serialize a type which converts to a primitive a System.InvalidOperationException : The requested operation requires an element of type 'Object', but the target element has type 'Number'. is thrown in PolymorphicObjectConverter.Write. It always expects types to be written as objects.
Steps to Reproduce
[JsonConverter(typeof(MyNumberConverter))]
readonly struct MyNumber
{
public required ulong Number { get; set; }
}
class MyNumberConverter : JsonConverter<MyNumber>
{
public override MyNumber Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
return reader.GetUInt64();
}
public override void Write(Utf8JsonWriter writer, MyNumber value, JsonSerializerOptions options)
{
writer.WriteNumberValue(value.Number);
}
}
[Fact]
public void ElsaTest()
{
PolymorphicObjectConverter c = new(null!);
using var ms = new MemoryStream();
using var w = new Utf8JsonWriter(ms);
c.Write(w, new MyNumber() { Number = 123UL }, JsonSerializerOptions.Default);
}