For this recipe, we need to perform the following steps:
- First, let's create the classes for events and commands. Create a file named FriendModel.scala inside the com.packt.chapter6 package with the following content:
package com.packt.chapter6 case class AddFriend(friend: Friend) case class RemoveFriend(friend: Friend) case class Friend(id: String) sealed trait FriendEvent case class FriendAdded(friend: Friend) extends FriendEvent case class FriendRemoved(friend: Friend) extends FriendEvent case class FriendState(friends: Vector[Friend] = Vector.empty[Friend]) { def update(evt: FriendEvent) = evt match { case FriendAdded(friend) => copy(friends :+ friend) case FriendRemoved(friend) => copy(friends.filterNot(_ == friend)) ...
