Merge pull request #1902 from dwijnand/define-project-settings-with-SettingsDefinition

Define Project.settings with SettingsDefinition.

main/src/main/scala/sbt/Project.scala

@@ -141,7 +141,7 @@ sealed trait Project extends ProjectDefinition[ProjectReference] {
   def aggregate(refs: ProjectReference*): Project = copy(aggregate = (aggregate: Seq[ProjectReference]) ++ refs)
 
   /** Appends settings to the current settings sequence for this project. */
-  def settings(ss: Setting[_]*): Project = copy(settings = (settings: Seq[Setting[_]]) ++ ss)
+  def settings(ss: SettingsDefinition*): Project = copy(settings = (settings: Seq[Setting[_]]) ++ ss.flatMap(_.settings))
 
   @deprecated("Use settingSets method.", "0.13.5")
   def autoSettings(select: AddSettings*): Project = settingSets(select.toSeq: _*)

notes/0.13.8/define-project-settings-with-settings-definition.markdown

@@ -0,0 +1,32 @@
+  [@dwijnand]: https://github.com/dwijnand
+  [1902]: https://github.com/sbt/sbt/pull/1902
+
+### Fixes with compatibility implications
+
+### Improvements
+
+- Facilitate nicer ways of declaring project settings. See below. [#1902][1902] by [@dwijnand][@dwijnand]
+
+### Bug fixes
+
+### Nicer ways of declaring project settings
+
+Now a `Seq[Setting[_]]` can be passed to `Project.settings` without the needs for "varargs expansion", ie. `: _*`
+
+Instead of:
+
+    lazy val foo = project settings (sharedSettings: _*)
+
+It is now possible to do:
+
+    lazy val foo = project settings sharedSettings
+
+Also, `Seq[Setting[_]]` can be declared at the same level as individual settings in `Project.settings`, for instance:
+
+    lazy val foo = project settings (
+      sharedSettings,
+      version := "1.0",
+      someMoreSettings
+    )
+
+[#1902][1902] by [@dwijnand][@dwijnand]

sbt/src/sbt-test/project/settings-definition/build.sbt

@@ -0,0 +1,39 @@
+// Just checking that existing ways of
+// setting up projects typechecks
+
+val sharedSettings1 = Seq(
+  name := "sharedSettings1"
+)
+
+val sharedSettings2 = Seq[Setting[_]](
+  name := "sharedSettings2"
+)
+
+lazy val root = project in file(".")
+
+lazy val oldSchool = (project
+  settings ((sharedSettings1 ++ sharedSettings2): _*)
+  settings (
+    name := "pre seq settings"
+  )
+  settings (sharedSettings1: _*)
+  settings (
+    name := "mid seq settings"
+  )
+  settings (sharedSettings2: _*)
+  settings (
+    name := "post seq settings"
+  )
+)
+
+lazy val newSchool = (project
+  settings sharedSettings1
+  settings sharedSettings2
+  settings (
+    name := "pre seq settings",
+    sharedSettings1,
+    name := "mid seq settings",
+    sharedSettings2,
+    name := "post seq settings"
+  )
+)

sbt/src/sbt-test/project/settings-definition/test

@@ -0,0 +1 @@
+> about