Fix Json.Num.apply for floats, doubles and java.math.BigInteger (#1299)

Author: plokhotnyuk

zio-json/shared/src/main/scala/zio/json/ast/ast.scala

@@ -536,10 +536,10 @@ object Json {
       if (value.isValidLong) apply(value.toLong)
       else new Json.Num(new java.math.BigDecimal(value.bigInteger))
     def apply(value: java.math.BigInteger): Num =
-      if (value.bitCount < 64) apply(value.longValue)
+      if (value.bitLength < 64) apply(value.longValue)
       else new Json.Num(new java.math.BigDecimal(value))
-    def apply(value: Float): Num  = new Num(new java.math.BigDecimal(value.toString))
-    def apply(value: Double): Num = new Num(new java.math.BigDecimal(value))
+    def apply(value: Float): Num  = new Num(new java.math.BigDecimal(SafeNumbers.toString(value)))
+    def apply(value: Double): Num = new Num(new java.math.BigDecimal(SafeNumbers.toString(value)))
 
     implicit val decoder: JsonDecoder[Num] = new JsonDecoder[Num] {
       def unsafeDecode(trace: List[JsonError], in: RetractReader): Num =

zio-json/shared/src/test/scala/zio/json/ast/JsonSpec.scala

@@ -5,11 +5,32 @@ import zio.json._
 import zio.test.Assertion._
 import zio.test._
 
+import java.math.BigInteger
+
 object JsonSpec extends ZIOSpecDefault {
 
   val spec: Spec[Environment, Any] =
     suite("Json")(
       suite("apply")(
+        test("Num()") {
+          assertTrue(Json.Num(0).toString == "0") &&
+          assertTrue(Json.Num(0.0).toString == "0.0") &&
+          assertTrue(Json.Num(1.0).toString == "1.0") &&
+          assertTrue(Json.Num(-0.0).toString == "0.0") &&
+          assertTrue(Json.Num(-1.0).toString == "-1.0") &&
+          assertTrue(Json.Num(7: Byte).toString == "7") &&
+          assertTrue(Json.Num(777: Short).toString == "777") &&
+          assertTrue(Json.Num(123456789).toString == "123456789") &&
+          assertTrue(Json.Num(1.2345678f).toString == "1.2345678") &&
+          assertTrue(Json.Num(1.2345678901234567).toString == "1.2345678901234567") &&
+          assertTrue(Json.Num(1234567890123456789L).toString == "1234567890123456789") &&
+          assertTrue(Json.Num(BigInteger.valueOf(1234567890123456789L)).toString == "1234567890123456789") &&
+          assertTrue(Json.Num(new BigInteger("12345678901234567890")).toString == "12345678901234567890") &&
+          assertTrue(Json.Num(BigInt(1234567890123456789L)).toString == "1234567890123456789") &&
+          assertTrue(Json.Num(BigInt("12345678901234567890")).toString == "12345678901234567890") &&
+          assertTrue(Json.Num(BigDecimal(1234567890123456789L)).toString == "1234567890123456789") &&
+          assertTrue(Json.Num(BigDecimal("12345678901234567890")).toString == "12345678901234567890")
+        },
         test("Bool()") {
           assertTrue(Json.Bool.True eq Json.Bool(true)) &&
           assertTrue(Json.Bool.False eq Json.Bool(false))