Do not implement Instant: java.io.Serializable

Author: dkhalanskyjb

core/jvm/src/Instant.kt

@@ -22,7 +22,7 @@ import java.time.Clock as jtClock
 @Serializable(with = InstantIso8601Serializer::class)
 public actual class Instant internal constructor(
     internal val value: jtInstant
-) : Comparable<Instant>, java.io.Serializable {
+) : Comparable<Instant> {
 
     public actual val epochSeconds: Long
         get() = value.epochSecond
@@ -100,8 +100,6 @@ public actual class Instant internal constructor(
         internal actual val MIN: Instant = Instant(jtInstant.MIN)
         internal actual val MAX: Instant = Instant(jtInstant.MAX)
     }
-
-    private fun writeReplace(): Any = Ser(Ser.INSTANT_TAG, this)
 }
 
 private fun Instant.atZone(zone: TimeZone): java.time.ZonedDateTime = try {

core/jvm/src/internal/Ser.kt

@@ -16,11 +16,6 @@ internal class Ser(private var typeTag: Int, private var value: Any?) : External
         out.writeByte(typeTag)
         val value = this.value
         when (typeTag) {
-            INSTANT_TAG -> {
-                value as Instant
-                out.writeLong(value.epochSeconds)
-                out.writeInt(value.nanosecondsOfSecond)
-            }
             DATE_TAG -> {
                 value as LocalDate
                 out.writeLong(value.value.toEpochDay())
@@ -45,8 +40,6 @@ internal class Ser(private var typeTag: Int, private var value: Any?) : External
     override fun readExternal(`in`: ObjectInput) {
         typeTag = `in`.readByte().toInt()
         value = when (typeTag) {
-            INSTANT_TAG ->
-                Instant.fromEpochSeconds(`in`.readLong(), `in`.readInt())
             DATE_TAG ->
                 LocalDate(java.time.LocalDate.ofEpochDay(`in`.readLong()))
             TIME_TAG ->
@@ -66,10 +59,9 @@ internal class Ser(private var typeTag: Int, private var value: Any?) : External
 
     companion object {
         private const val serialVersionUID: Long = 0L
-        const val INSTANT_TAG = 1
         const val DATE_TAG = 2
         const val TIME_TAG = 3
         const val DATE_TIME_TAG = 4
         const val UTC_OFFSET_TAG = 10
     }
-}
+}

core/jvm/test/JvmSerializationTest.kt

@@ -10,14 +10,6 @@ import kotlin.test.*
 
 class JvmSerializationTest {
 
-    @Test
-    fun serializeInstant() {
-        roundTripSerialization(Instant.fromEpochSeconds(1234567890, 123456789))
-        roundTripSerialization(Instant.MIN)
-        roundTripSerialization(Instant.MAX)
-        expectedDeserialization(Instant.parse("+150000-04-30T12:30:25.555998Z"), "0d010000043fa44d82612123db30")
-    }
-
     @Test
     fun serializeLocalTime() {
         roundTripSerialization(LocalTime(12, 34, 56, 789))