Alteration should return a Future

guardian · Feb 19, 2018 · e98cb7d · e98cb7d
1 parent 6e10fe8
commit e98cb7d
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/main/scala/com/gu/Box.scala b/src/main/scala/com/gu/Box.scala
@@ -2,7 +2,7 @@ package com.gu
 
 import java.util.concurrent.atomic.AtomicReference
 
-import scala.concurrent.Future
+import scala.concurrent.{ExecutionContext, Future}
 
 abstract class Box[T] {
   def get(): T
@@ -12,7 +12,7 @@ abstract class Box[T] {
   def send(f: T => T): Unit
 
   def alter(t: T): Future[T]
-  def alter(f: T => T): Future[T]
+  def alter(f: T => Future[T])(implicit ec: ExecutionContext): Future[T]
 
   def map[A](f: T => A): Box[A]
   def flatMap[A](f: T => Box[A]): Box[A]
@@ -32,7 +32,7 @@ private class AtomicRefBox[T](t: T) extends Box[T] {
   def send(f: T => T): Unit = ref.updateAndGet(t => f(t))
 
   def alter(t: T): Future[T] = Future.successful(ref.updateAndGet(_ => t))
-  def alter(f: T => T): Future[T] = Future.successful(ref.updateAndGet(t => f(t)))
+  def alter(f: T => Future[T])(implicit ec: ExecutionContext): Future[T] = f(t).map(t => ref.updateAndGet(_ => t))
 
   def map[A](f: T => A): Box[A] = new AtomicRefBox[A](f(get()))
   def flatMap[A](f: T => Box[A]): Box[A] = f(get())