Merge pull request #541 from pedorich-n/option-companion-object-methods

Option.when and Option.unless added

Author: lrytz

compat/src/main/scala-2.11_2.12/scala/collection/compat/PackageShared.scala

@@ -282,6 +282,9 @@ private[compat] trait PackageShared {
   implicit def toMapViewExtensionMethods[K, V, C <: scala.collection.Map[K, V]](
       self: IterableView[(K, V), C]): MapViewExtensionMethods[K, V, C] =
     new MapViewExtensionMethods[K, V, C](self)
+
+  implicit def toOptionCompanionExtension(fact: Option.type): OptionCompanionExtensionMethods =
+    new OptionCompanionExtensionMethods(fact)
 }
 
 class ImmutableSortedMapExtensions(private val fact: i.SortedMap.type) extends AnyVal {
@@ -587,3 +590,9 @@ class MutableQueueExtensionMethods[Element](private val self: m.Queue[Element])
   def enqueueAll(iter: c.Iterable[Element]): Unit =
     self.enqueue(iter.toIndexedSeq: _*)
 }
+
+class OptionCompanionExtensionMethods(private val fact: Option.type) extends AnyVal {
+  def when[A](cond: Boolean)(a: => A): Option[A] = if (cond) Some(a) else None
+
+  @inline def unless[A](cond: Boolean)(a: => A): Option[A] = when(!cond)(a)
+}

compat/src/test/scala/test/scala/collection/OptionTest.scala

@@ -0,0 +1,48 @@
+/*
+ * Scala (https://www.scala-lang.org)
+ *
+ * Copyright EPFL and Lightbend, Inc.
+ *
+ * Licensed under Apache License 2.0
+ * (http://www.apache.org/licenses/LICENSE-2.0).
+ *
+ * See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ */
+
+package test.scala.collection
+
+import scala.collection.compat._
+import org.junit.Test
+import org.junit.Assert._
+
+class OptionTest {
+
+  private val value: String        = "example"
+  private val some: Option[String] = Some(value)
+  private val none: Option[String] = None
+
+  @Test
+  def testWhenTrue: Unit = {
+    val option = Option.when(true)(value)
+    assertEquals(option, some)
+  }
+
+  @Test
+  def testWhenFalse: Unit = {
+    val option = Option.when(false)(value)
+    assertEquals(option, none)
+  }
+
+  @Test
+  def testUnlessTrue: Unit = {
+    val option = Option.unless(true)(value)
+    assertEquals(option, none)
+  }
+
+  @Test
+  def testUnlessFalse: Unit = {
+    val option = Option.unless(false)(value)
+    assertEquals(option, some)
+  }
+}