What would be the recommended way to serialize/des...

# serialization

[Martin Gaens]

What would be the recommended way to serialize/deserialize money amounts? I'm getting a decimal amount of money from an API and BigDecimal doesn't have a default serializer. Is the best thing to do creating a serializer for BigDecimal?

[ephemient]

serialize it as a string for portability - many JSON implementations don't support primitive numbers outside of Javascript's range, and that includes kotlinx.serialization

[ephemient]

but yes, just write your own serializer

[ephemient]

object BigDecimalSerializer : KSerializer<BigDecimal> {
    override val descriptor: SerialDescriptor =
        PrimitiveSerialDescriptor("java.math.BigDecimal", PrimitiveKind.STRING)
    override fun serialize(encoder: Encoder, value: BigDecimal) {
        encoder.encodeString(value.toString())
    }
    override fun deserialize(decoder: Decoder): BigDecimal {
        return decoder.decodeString().toBigDecimal()
    }
}

[Martin Gaens]

I can't serialize it as a String because the API needs a decimal number. Something like:
{"money":1.55} and not {"money":"1.55"}

[ephemient]

1. can't serialize arbitrary numbers in kotlinx.serialization https://github.com/Kotlin/kotlinx.serialization/issues/1051
2. JSON implementations have no requirement to be able to handle arbitrary numbers https://kotlinlang.slack.com/archives/C7A1U5PTM/p1655820506656319?thread_ts=1655807410.755689&cid=C7A1U5PTM