Introduce the importsOrder configuration (scalacenter#23)

README.adoc

@@ -208,6 +208,7 @@ import scala.collection.mutable.{ArrayBuffer, Buffer, StringBuilder}
 ----
 --
 
+[[groups]]
 === `groups`
 
 ==== Description
@@ -401,7 +402,7 @@ import sun.misc.BASE64Encoder
 
 ==== Description
 
-Sort import selectors within a single import expression by the specified order.
+Specifies the order of grouped import selectors within a single import expression.
 
 ==== Value type
 
@@ -481,6 +482,96 @@ import foo.{~>, `symbol`, bar, Random}
 ----
 --
 
+=== `importsOrder`
+
+==== Description
+
+Specifies the order of import statements within import groups defined by the <<groups,`OrganizeImports.groups`>> option.
+
+==== Value type
+
+Enum: `Ascii | SymbolsFirst`
+
+`Ascii`::
+Sort import statements by ASCII codes.
+
+`SymbolsFirst`::
+Put wildcard imports and grouped imports with braces first, otherwise same as `Ascii`. This is also the sorting order the IntelliJ IDEA Scala plugin picks.
+
+==== Deafult value
+
+`Ascii`
+
+==== Example
+
+`Ascii`::
++
+--
+Configuration:
+
+[source,hocon]
+----
+OrganizeImports {
+  groupedImports = Keep
+  importsOrder = Ascii
+}
+----
+
+Before:
+
+[source,scala]
+----
+import scala.concurrent._
+import scala.concurrent.{Future, Promise}
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent.duration
+----
+
+After:
+
+[source,scala]
+----
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent._
+import scala.concurrent.duration
+import scala.concurrent.{Promise, Future}
+----
+--
+
+`SymbolsFirst`::
++
+--
+Configuration:
+
+[source,hocon]
+----
+OrganizeImports {
+  groupedImports = Keep
+  importsOrder = SymbolsFirst
+}
+----
+
+Before:
+
+[source,scala]
+----
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent._
+import scala.concurrent.duration
+import scala.concurrent.{Promise, Future}
+----
+
+After:
+
+[source,scala]
+----
+import scala.concurrent._
+import scala.concurrent.{Future, Promise}
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent.duration
+----
+--
+
 [[remove-unused]]
 === `removeUnused`
 

input/src/main/scala/fix/ImportsOrderSymbolsFirst.scala

@@ -0,0 +1,13 @@
+/*
+rules = [OrganizeImports]
+OrganizeImports.groupedImports = Keep
+OrganizeImports.importsOrder = SymbolsFirst
+ */
+package fix
+
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent._
+import scala.concurrent.duration
+import scala.concurrent.{Promise, Future}
+
+object ImportsOrderSymbolsFirst

output/src/main/scala/fix/ImportsOrderSymbolsFirst.scala

@@ -0,0 +1,8 @@
+package fix
+
+import scala.concurrent._
+import scala.concurrent.{Future, Promise}
+import scala.concurrent.ExecutionContext.Implicits._
+import scala.concurrent.duration
+
+object ImportsOrderSymbolsFirst

rules/src/main/scala/fix/OrganizeImports.scala

@@ -171,14 +171,30 @@ class OrganizeImports(config: OrganizeImportsConfig) extends SemanticRule("Organ
 
   private def organizeImporters(importers: Seq[Importer]): Seq[Importer] = {
     import GroupedImports._
+    import ImportsOrder._
 
-    val xs = config.groupedImports match {
-      case Merge   => mergeImportersWithCommonPrefix(importers)
-      case Explode => explodeGroupedImportees(importers)
-      case Keep    => importers
+    val importeesSorted = {
+      config.groupedImports match {
+        case Merge   => mergeImportersWithCommonPrefix(importers)
+        case Explode => explodeGroupedImportees(importers)
+        case Keep    => importers
+      }
+    } map sortImportees
+
+    config.importsOrder match {
+      case Ascii =>
+        importeesSorted sortBy (_.syntax)
+
+      case SymbolsFirst =>
+        // Hack: This is a quick-n-dirty way to achieve a the import ordering provided by the
+        // IntelliJ IDEA Scala plugin. This implementation does not cover cases like quoted
+        // identifiers containg "._" and/or braces.
+        importeesSorted sortBy {
+          _.syntax
+            .replaceAll("\\._$", ".\0")
+            .replaceAll("[{}]", "\1")
+        }
     }
-
-    xs map sortImportees sortBy (_.syntax)
   }
 
   // Returns the index of the group to which the given importer belongs.

rules/src/main/scala/fix/OrganizeImportsConfig.scala

@@ -6,6 +6,17 @@ import metaconfig.generic.deriveDecoder
 import metaconfig.generic.deriveSurface
 import scalafix.internal.config.ReaderUtil
 
+sealed trait ImportsOrder
+
+object ImportsOrder {
+  case object Ascii extends ImportsOrder
+  case object SymbolsFirst extends ImportsOrder
+
+  implicit def reader: ConfDecoder[ImportsOrder] = ReaderUtil.fromMap {
+    List(Ascii, SymbolsFirst) groupBy (_.toString) mapValues (_.head)
+  }
+}
+
 sealed trait ImportSelectorsOrder
 
 object ImportSelectorsOrder {
@@ -32,9 +43,10 @@ object GroupedImports {
 
 final case class OrganizeImportsConfig(
   expandRelative: Boolean = false,
-  importSelectorsOrder: ImportSelectorsOrder = ImportSelectorsOrder.Ascii,
   groupedImports: GroupedImports = GroupedImports.Explode,
   groups: Seq[String] = Seq("re:javax?\\.", "scala.", "*"),
+  importSelectorsOrder: ImportSelectorsOrder = ImportSelectorsOrder.Ascii,
+  importsOrder: ImportsOrder = ImportsOrder.Ascii,
   removeUnused: Boolean = true
 )