zio-json - dealing with bigdecimal representation / published by https://github.com/dacr/code-examples-manager #9d4116ca-6856-455c-9c3d-8a0f0d1facbd/5e82cd5cda6154fd2fda1b8d0bf151c94ac8eb7

zio-json-644-bigdecimal.sc

// summary : zio-json - dealing with bigdecimal representation
// keywords : scala, zio, zio-json, @testable, bigdecimal, issue, @fail
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 9d4116ca-6856-455c-9c3d-8a0f0d1facbd
// created-on : 2022-07-02T08:45:35+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.2.2"
//> using dep "dev.zio::zio-json:0.5.0"
// ---------------------

// https://github.com/zio/zio-json/issues/644
// https://github.com/scala/bug/issues/9670

import zio.*
import zio.json.*
import zio.json.ast.Json.Num
import java.math.BigDecimal as JBigDecimal
import scala.math.BigDecimal as SBigDecimal

assert(SBigDecimal(42.0) == SBigDecimal(42))
assert(JBigDecimal(42.0) == JBigDecimal(42))

assert(SBigDecimal("42.0") == SBigDecimal("42"))
assert(JBigDecimal("42.0") != JBigDecimal("42"))
assert(JBigDecimal("42.0").stripTrailingZeros() == JBigDecimal("42"))
assert(JBigDecimal("420.00") != JBigDecimal("420.0"))

assert("42".fromJson[Num].toOption.get.value == JBigDecimal(42))
assert("42.0".fromJson[Num].toOption.get.value != JBigDecimal(42))
assert("42.0".fromJson[Num].toOption.get.value != JBigDecimal(42.0))
assert("42.0".fromJson[Num].toOption.get.value.stripTrailingZeros() == JBigDecimal(42))     // fix proposal - it makes sense
assert("42.0".fromJson[Num].toOption.get.value.stripTrailingZeros() == JBigDecimal(42.0))   // fix proposal - it makes sense
assert("42.0".fromJson[Num].toOption.get.value.stripTrailingZeros() != JBigDecimal("42.0")) // but keep in mind that of course

assert(JBigDecimal("420.0").stripTrailingZeros != JBigDecimal(420.0)) // Because it is a power of 10 !
assert(JBigDecimal("42.0").stripTrailingZeros == JBigDecimal(42.0)) // Because it is not a power of 10
assert(JBigDecimal("420.0").stripTrailingZeros == JBigDecimal("4.2E+2"))
assert(JBigDecimal("420.0").stripTrailingZeros.toString == "4.2E+2")

assert(JBigDecimal("420.0").setScale(1) != JBigDecimal(420.0))
assert(JBigDecimal("420.0").setScale(1).toString == "420.0")
assert(JBigDecimal("420.0").setScale(0).toString == "420")

assert("42.0".fromJson[SBigDecimal].toOption.get == SBigDecimal("42"))
assert("42.0".fromJson[SBigDecimal].toOption.get == SBigDecimal("42"))

println("JBigDecimal is also a big mess, and I would say that equality is based on the rendered form of the value, and not only its intrinsic value")