def taskIf[A](a: A): Initialize[Task[A]]

Make `Def.taskIf` accept pure `A` type, as opposed to `Def.task { ... }`.

main-settings/src/main/scala/sbt/Def.scala

@@ -235,7 +235,7 @@ object Def extends Init[Scope] with TaskMacroExtra with InitializeImplicits {
   def inputTask[T](t: T): Def.Initialize[InputTask[T]] = macro inputTaskMacroImpl[T]
   def inputTaskDyn[T](t: Def.Initialize[Task[T]]): Def.Initialize[InputTask[T]] =
     macro inputTaskDynMacroImpl[T]
-  def taskIf[T](a: Def.Initialize[Task[T]]): Def.Initialize[Task[T]] = macro taskIfMacroImpl[T]
+  def taskIf[T](a: T): Def.Initialize[Task[T]] = macro taskIfMacroImpl[T]
 
   private[sbt] def selectITask[A, B](
       fab: Initialize[Task[Either[A, B]]],

main-settings/src/main/scala/sbt/std/TaskMacro.scala

@@ -120,10 +120,10 @@ object TaskMacro {
 
   def taskIfMacroImpl[A: c.WeakTypeTag](
       c: blackbox.Context
-  )(a: c.Expr[Initialize[Task[A]]]): c.Expr[Initialize[Task[A]]] = {
+  )(a: c.Expr[A]): c.Expr[Initialize[Task[A]]] = {
     import c.universe._
     def mkIfS(cond: Tree, thenp: Tree, elsep: Tree): Tree =
-      q"""Def.ifS(Def.task($cond))($thenp)($elsep)"""
+      q"""Def.ifS(Def.task($cond))(Def.task($thenp))(Def.task($elsep))"""
     a.tree match {
       case Block(stat, If(cond, thenp, elsep)) =>
         c.Expr[Initialize[Task[A]]](mkIfS(Block(stat, cond), thenp, elsep))

main/src/main/scala/sbt/Defaults.scala

@@ -2129,8 +2129,8 @@ object Defaults extends BuildCommon {
 
   def dependencyResolutionTask: Def.Initialize[Task[DependencyResolution]] =
     Def.taskIf {
-      if (useCoursier.value) Def.task { CoursierDependencyResolution(csrConfiguration.value) } else
-        Def.task { IvyDependencyResolution(ivyConfiguration.value, CustomHttp.okhttpClient.value) }
+      if (useCoursier.value) CoursierDependencyResolution(csrConfiguration.value)
+      else IvyDependencyResolution(ivyConfiguration.value, CustomHttp.okhttpClient.value)
     }
 }
 
@@ -2949,16 +2949,14 @@ object Classpaths {
 
   def publishTask(config: TaskKey[PublishConfiguration]): Initialize[Task[Unit]] =
     Def.taskIf {
-      if ((publish / skip).value)
-        Def.task {
-          val s = streams.value
-          val ref = thisProjectRef.value
-          s.log.debug(s"Skipping publish* for ${ref.project}")
-        } else
-        Def.task {
-          val s = streams.value
-          IvyActions.publish(ivyModule.value, config.value, s.log)
-        }
+      if ((publish / skip).value) {
+        val s = streams.value
+        val ref = thisProjectRef.value
+        s.log.debug(s"Skipping publish* for ${ref.project}")
+      } else {
+        val s = streams.value
+        IvyActions.publish(ivyModule.value, config.value, s.log)
+      }
     } tag (Tags.Publish, Tags.Network)
 
   val moduleIdJsonKeyFormat: sjsonnew.JsonKeyFormat[ModuleID] =

sbt/src/sbt-test/actions/ifs/build.sbt

@@ -12,8 +12,8 @@ lazy val root = (project in file("."))
     trueAction := { IO.write(output.value, s"true\n", append = true) },
     falseAction := { IO.write(output.value, s"false\n", append = true) },
     foo := (Def.taskIf {
-      if (condition.value) trueAction
-      else falseAction
+      if (condition.value) trueAction.value
+      else falseAction.value
     }).value,
     TaskKey[Unit]("check") := {
       val lines = IO.read(output.value).linesIterator.toList