MessagePack Float32 reading error

Reading Float values from MessagePack Float32 values should be supported according to the documentation and it should be consistent with the writing behavior.

Currently, writing Float values creates a MessagePack Float32 value but an equivalent reading operation causes the FloatReader to report an unexpected data type error.

Environment

uPickle: 1.4.0
Scala: 3.0.0
JRE: 17

Reproduce

import upickle.default._

object Main extends App:

  println(readBinary[Float](writeMsg(1.0f)))

Result

upickle.core.Abort: expected number got float32
    at upickle.core.SimpleVisitor.visitFloat32(SimpleVisitor.scala:29)
    at upickle.core.SimpleVisitor.visitFloat32$(SimpleVisitor.scala:7)
    at upickle.implicits.Readers$$anon$5.visitFloat32(Readers.scala:59)
    at upack.Msg$.transform(Msg.scala:182)
    at upack.Msg.transform(Msg.scala:23)
    at upack.Msg.transform$(Msg.scala:21)
    at upack.Float32.transform(Msg.scala:107)
    at upickle.Api.readBinary$$anonfun$1(Api.scala:30)
    at upickle.core.TraceVisitor$.withTrace(TraceVisitor.scala:18)
    at upickle.Api.readBinary(Api.scala:30)
    at upickle.Api.readBinary$(Api.scala:17)
    at upickle.default$.readBinary(Api.scala:133)
    at Main$.<clinit>(main.scala:6)

Expected

1.0

Fix

Add the following method override to the FloatReader:

override def visitFloat32(d: Float, index: Int) = d

Workaround

Add the following implicit reader override to your custom configuration:

  implicit override val FloatReader: Reader[Float] =
    new SimpleReader[Float] {

      override def expectedMsg = "expected number"
      override def visitString(s: CharSequence, index: Int) = s.toString.toFloat
      override def visitInt32(d: Int, index: Int) = d.toFloat
      override def visitInt64(d: Long, index: Int) = d.toFloat
      override def visitUInt64(d: Long, index: Int) = d.toFloat
      override def visitFloat32(d: Float, index: Int) = d
      override def visitFloat64(d: Double, index: Int) = d.toFloat
      override def visitFloat64StringParts(s: CharSequence, decIndex: Int, expIndex: Int, index: Int) =
        s.toString.toFloat
    }

ID: 354 Original Author: martin-ockajak

amnaredo / test