Play Framework can't import play-json implicit reader & writer - scala

Question

I have a controller in Play Framework (2.5.4) managed by sbt.
userController.scala
package controllers
// import models.User
import com.neruti.User
import play.api._
import play.api.mvc._
import play.api.libs.json._
import play.api.libs.functional.syntax._
import pdi.jwt._
import pdi.jwt.{JwtPlayImplicits, JwtSession}
import play.api.mvc.Controller
import java.time.LocalDate
import java.util.UUID
class UserProfileController extends Controller with JwtPlayImplicits {
def putUserProfile = Action(parse.json) {request =>
val userProfile: JsResult[User] = request.body.validate[User]
userProfile.map {
case user:User => Ok("Its good")
}.recoverTotal{
e=>BadRequest("Detected error" + JsError.toFlatJson(e))
}
}
}
Below is User model in another separate module(core) managed by Maven. A multi-module maven pattern.
User.scala
package com.neruti
import play.api.libs.json._
import play.api.data.validation.ValidationError
import play.api.libs.functional.syntax._
case class User(
username: String,
email: Option[String] = None
)
object User {
implicit val userReads: Reads[User] =(
(__ \ "username").read[String] and
(__ \ "email").readNullable[String]
)(User.apply _)
implicit val userWrites: Writes[User] =(
(__ \ "username").write[String] and
(__ \ "email").writeNullable[String]
)(unlift (User.unapply))
}
Issue is inside the userController.scala, it can't see implicit JSON reader&writer in scope.
userController.scala:44: No Json deserializer found for type com.neruti.User. Try to implement an implicit Reads or Format for this type.
[error] val userProfile: JsResult[User] = request.body.validate[User]
Did import com.neruti.User._, doesn't import implicit methods.
However, if I uncommented import models.User, using models package inside play, it works.
Any advice is much appreciated.

Answer 1

For some reason I can't comprehend, after I move Reads[T] and Writes[T] converters to another object, it works.