MsgPack.ExtensionType for Date

New to Julia
1

I am trying to write the Julia end of an RPC-over-RabbitMQ relationship. The other side (written in Ruby) uses a MsgPack extension for dates. I receive this:

MsgPack.Extension(1, UInt8[0x07, 0xe6, 0x02, 0x1c])

I can make my end send this with pack, but I can’t make my end convert this to a Date with unpack. This is what I have so far, based on the documentation for MsgPack.ExtensionType:

module test_msg_pack_ext

using Dates
using MsgPack
using Test

function pack_date(date::Date)::MsgPack.Extension
        year_u16 = convert(UInt16, year(date))
        year_hi = UInt8(year_u16 >> 8)
        year_lo = UInt8(year_u16 << 8 >> 8)
        return MsgPack.Extension(0x01, UInt8[year_hi, year_lo, month(date), day(date)])
end

function unpack_date(ext::MsgPack.Extension)::Date
        year = ext.data[1] << 8 | ext.data[2]
        return Date(year, ext.data[3], ext.data[4])
end

MsgPack.msgpack_type(::Type{Dates.Date}) = MsgPack.ExtensionType()
MsgPack.to_msgpack(::MsgPack.ExtensionType, date::Dates.Date) = pack_date(date)
MsgPack.from_msgpack(::Type{Dates.Date}, ext::MsgPack.Extension) = unpack_date(ext)

@test pack(MsgPack.Extension(1, UInt8[0x07, 0xe6, 0x02, 0x1c])) == pack(Date(2022, 2, 28))
@test Date(2022, 2, 28) == unpack(UInt8[0xd6, 0x01, 0x07, 0xe6, 0x02, 0x1c])
    
end

# =>
engine/msg_pack_ext.jl: Test Failed at .../msg_pack_ext.jl:25
  Expression: Date(2022, 2, 28) == unpack(UInt8[0xd6, 0x01, 0x07, 0xe6, 0x02, 0x1c])
   Evaluated: Dates.Date("2022-02-28") == MsgPack.Extension(1, UInt8[0x07, 0xe6, 0x02, 0x1c])

That makes sense to me. I haven’t done anything to map extension type 1 to my code. But I can’t figure out how to do that.

Any help would be greatly appreciated.

Thanks,
Sheldon.