JsonNumber.truncateToInt does not work correctly

[kushnerdmitry]

truncateToInt does not truncate Long number that is greater than Int.MaxValue to Int.MaxValue

Example(in scala repl)
Input:

import argonaut.JsonLong

val intMaxPlusOne = JsonLong(2147483648L).truncateToInt
val intMax = JsonLong(2147483647).truncateToInt
val long = JsonLong(100000000000L).truncateToInt

Output:

intMaxPlusOne: Int = -2147483648
intMax: Int = 2147483647
long: Int = 1215752192

Another example with codecs(also in scala repl):
Input:

import argonaut.{CodecJson, Json}
import argonaut.Argonaut._

val json = Json(
  "long" := 10002100000000L
)

case class DecodedInt(truncatedInt: Int)

implicit def DecodedIntCodec: CodecJson[DecodedInt] = 
  casecodec1(DecodedInt.apply, DecodedInt.unapply)("long")

val decoded = json.as[DecodedInt].value.get.truncatedInt

Output:

json: argonaut.Json = {"long":10002100000000}

defined class DecodedInt

DecodedIntCodec: argonaut.CodecJson[DecodedInt]

decoded: Int = -878832384

Scala version: 2.12.10
Argonaut version: 6.2.5

[k5ta]

truncateToInt implementation:

• argonaut 6.1.x: def truncateToInt: Int = toDouble.toInt

• argonaut 6.2.x: def truncateToInt: Int = toBigDecimal.toInt

I suppose that these changes were made due to the addition of lazy val toDouble in JsonNumber instead JsonDecimal. truncateToInt will work with truncateToDouble instead of toBigDecimal.