Converts LocalDate and Instant from java.time to/from BSONDateTime

BsonImplicits.scala

import java.time.{Instant, LocalDate, ZoneOffset}

import reactivemongo.bson._

object BsonImplicits {

  implicit object LocalDateBsonReaderWriter extends BSONReader[BSONValue, LocalDate] with BSONWriter[LocalDate, BSONDateTime] {
    override def read(bson: BSONValue): LocalDate = bson match {
      case BSONDateTime(millis) => Instant.ofEpochMilli(millis).atZone(ZoneOffset.UTC).toLocalDate
      case BSONLong(millis) => Instant.ofEpochMilli(millis).atZone(ZoneOffset.UTC).toLocalDate
      case _ => throw new IllegalArgumentException(s"Cannot convert $bson to java.time.LocalDate")
    }

    override def write(date: LocalDate): BSONDateTime =
      BSONDateTime(date.atStartOfDay().atZone(ZoneOffset.UTC).toInstant.toEpochMilli)
  }


  implicit object InstantBsonReaderWriter extends BSONReader[BSONValue, Instant] with BSONWriter[Instant, BSONDateTime] {
    override def read(bson: BSONValue): Instant = bson match {
      case BSONDateTime(millis) => Instant.ofEpochMilli(millis)
      case BSONLong(millis) => Instant.ofEpochMilli(millis)
      case _ => throw new IllegalArgumentException(s"Cannot convert $bson to java.time.Instant")
    }

    override def write(instant: Instant): BSONDateTime = BSONDateTime(instant.toEpochMilli)
  }

}