Stacking1.scala

package mixin

import collection._

object Stacking1 extends App {

  case class Company(id: String, name: String, address: String, active: Boolean)

  case class ReferenceData(companies: Map[String, Company])

  trait Suite {

    def beforeEach() {}

  }

  trait ReferenceDataBuilder {

    var referenceData = ReferenceData(Map.empty)

    def add(company: Company): Unit = {
      referenceData = referenceData.copy(companies = referenceData.companies + (company.id -> company))
    }

    def modifyCompany(companyId: String, name: Option[String] = None, address: Option[String] = None, active: Option[Boolean] = None): Unit = {
      val existingCompany = referenceData.companies(companyId)
      val newCompany = existingCompany.copy(
        name = name.getOrElse(existingCompany.name),
        address = address.getOrElse(existingCompany.address),
        active = active.getOrElse(existingCompany.active)
      )
      referenceData = referenceData.copy(companies = referenceData.companies + (companyId -> newCompany))
    }

  }

  trait Company1 extends Suite with ReferenceDataBuilder {

    override def beforeEach() {
      super.beforeEach()
      add(Company("1", "ABC Limited", "123 Main Street", active = true))
    }

  }

  trait Company2 extends Suite with ReferenceDataBuilder {

    override def beforeEach() {
      super.beforeEach()
      add(Company("2", "XYZ Inc.", "456 Broadway Avenue", active = true))
    }

  }

  class MyTest1 extends ReferenceDataBuilder with Company1 {

    beforeEach()

    def run() {
      println(referenceData)
    }

  }

  val test1 = new MyTest1
  test1.run() // ReferenceData(Map(1 -> Company(1,ABC Limited,123 Main Street,true)))

  class MyTest2 extends ReferenceDataBuilder with Company1 with Company2 {

    beforeEach()

    def run() {
      modifyCompany("1", active = Some(false))
      println(referenceData)
    }

  }

  val test2 = new MyTest2
  test2.run() // ReferenceData(Map(1 -> Company(1,ABC Limited,123 Main Street,false), 2 -> Company(2,XYZ Inc.,456 Broadway Avenue,true)))

}