From 60bc28829bed07dbaf858fbd2934e91fb75b885d Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Fri, 11 Mar 2016 17:18:57 +0000
Subject: [PATCH] Add Append & Remove instances for Option

---
 main/settings/src/main/scala/sbt/Append.scala |  5 +++
 main/settings/src/main/scala/sbt/Remove.scala |  5 +++
 sbt/src/sbt-test/project/append/build.sbt     | 33 +++++++++++++++++++
 sbt/src/sbt-test/project/append/test          |  1 +
 sbt/src/sbt-test/project/remove/build.sbt     | 12 +++++--
 5 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 sbt/src/sbt-test/project/append/build.sbt
 create mode 100644 sbt/src/sbt-test/project/append/test

diff --git a/main/settings/src/main/scala/sbt/Append.scala b/main/settings/src/main/scala/sbt/Append.scala
index b558aab02..c2716d703 100644
--- a/main/settings/src/main/scala/sbt/Append.scala
+++ b/main/settings/src/main/scala/sbt/Append.scala
@@ -56,4 +56,9 @@ object Append {
     def appendValues(a: Map[A, B], b: Map[X, Y]): Map[A, B] = a ++ b
     def appendValue(a: Map[A, B], b: (X, Y)): Map[A, B] = a + b
   }
+  implicit def appendOption[T]: Sequence[Seq[T], Option[T], Option[T]] =
+    new Sequence[Seq[T], Option[T], Option[T]] {
+      def appendValue(a: Seq[T], b: Option[T]): Seq[T] = b.fold(a)(a :+ _)
+      def appendValues(a: Seq[T], b: Option[T]): Seq[T] = b.fold(a)(a :+ _)
+    }
 }
diff --git a/main/settings/src/main/scala/sbt/Remove.scala b/main/settings/src/main/scala/sbt/Remove.scala
index 50c97ee88..ac33e0b67 100644
--- a/main/settings/src/main/scala/sbt/Remove.scala
+++ b/main/settings/src/main/scala/sbt/Remove.scala
@@ -17,4 +17,9 @@ object Remove {
     def removeValue(a: Seq[T], b: V): Seq[T] = a filterNot b.==
     def removeValues(a: Seq[T], b: Seq[V]): Seq[T] = a diff b
   }
+  implicit def removeOption[T]: Sequence[Seq[T], Option[T], Option[T]] =
+    new Sequence[Seq[T], Option[T], Option[T]] {
+      def removeValue(a: Seq[T], b: Option[T]): Seq[T] = b.fold(a)(a filterNot _.==)
+      def removeValues(a: Seq[T], b: Option[T]): Seq[T] = b.fold(a)(a filterNot _.==)
+    }
 }
diff --git a/sbt/src/sbt-test/project/append/build.sbt b/sbt/src/sbt-test/project/append/build.sbt
new file mode 100644
index 000000000..d48fdd77c
--- /dev/null
+++ b/sbt/src/sbt-test/project/append/build.sbt
@@ -0,0 +1,33 @@
+val intsTask = taskKey[Seq[Int]]("A seq of ints task")
+val intsSetting = settingKey[Seq[Int]]("A seq of ints setting")
+val intsFromScalaV = settingKey[Seq[Int]]("a seq of ints from scalaVersion")
+
+scalaVersion := "2.11.6"
+
+intsTask := Nil
+intsTask += 3
+intsTask ++= Seq(1, 2)
+intsTask += Option(6)
+intsTask ++= Option(7)
+
+intsSetting := Nil
+intsSetting += 3
+intsSetting ++= Seq(1, 2)
+intsSetting += Option(6)
+intsSetting ++= Option(7)
+
+intsFromScalaV := Nil
+intsFromScalaV += { if (scalaVersion.value == "2.11.6") 3 else 5 }
+intsFromScalaV ++= { if (scalaVersion.value == "2.11.6") Seq(1, 2) else Seq(4) }
+intsFromScalaV += { if (scalaVersion.value == "2.11.6") Option(6) else None }
+intsFromScalaV ++= { if (scalaVersion.value == "2.11.6") Option(7) else None }
+
+val check = taskKey[Unit]("Runs the check")
+check := {
+  assertEquals("intsTask", intsTask.value, Seq(3, 1, 2, 6, 7))
+  assertEquals("intsSetting", intsSetting.value, Seq(3, 1, 2, 6, 7))
+  assertEquals("intsFromScalaV", intsFromScalaV.value, Seq(3, 1, 2, 6, 7))
+}
+
+def assertEquals[T](label: String, actual: T, expect: T) =
+  assert(actual == expect, s"$label should be $expect but is $actual")
diff --git a/sbt/src/sbt-test/project/append/test b/sbt/src/sbt-test/project/append/test
new file mode 100644
index 000000000..15675b169
--- /dev/null
+++ b/sbt/src/sbt-test/project/append/test
@@ -0,0 +1 @@
+> check
diff --git a/sbt/src/sbt-test/project/remove/build.sbt b/sbt/src/sbt-test/project/remove/build.sbt
index 0b967394c..d3ae2985d 100644
--- a/sbt/src/sbt-test/project/remove/build.sbt
+++ b/sbt/src/sbt-test/project/remove/build.sbt
@@ -4,17 +4,23 @@ val intsFromScalaV = settingKey[Seq[Int]]("a seq of ints from scalaVersion")
 
 scalaVersion := "2.11.6"
 
-intsTask := Seq(1, 2, 3, 4, 5)
+intsTask := Seq(1, 2, 3, 4, 5, 6, 7)
 intsTask -= 3
 intsTask --= Seq(1, 2)
+intsTask -= Option(6)
+intsTask --= Option(7)
 
-intsSetting := Seq(1, 2, 3, 4, 5)
+intsSetting := Seq(1, 2, 3, 4, 5, 6, 7)
 intsSetting -= 3
 intsSetting --= Seq(1, 2)
+intsSetting -= Option(6)
+intsSetting --= Option(7)
 
-intsFromScalaV := Seq(1, 2, 3, 4, 5)
+intsFromScalaV := Seq(1, 2, 3, 4, 5, 6, 7)
 intsFromScalaV -= { if (scalaVersion.value == "2.11.6") 3 else 5 }
 intsFromScalaV --= { if (scalaVersion.value == "2.11.6") Seq(1, 2) else Seq(4) }
+intsFromScalaV -= { if (scalaVersion.value == "2.11.6") Option(6) else None }
+intsFromScalaV --= { if (scalaVersion.value == "2.11.6") Option(7) else None }
 
 val check = taskKey[Unit]("Runs the check")
 check := {