Router: implement align.beforeOpenParenXxxSite

docs/configuration.md

@@ -975,6 +975,19 @@ object a {
 }
 ```
 
+### `align.beforeOpenParenXxxSite`
+
+Aligns parameter groups (not parameters within a group) if using
+[`newlines.beforeOpenParenXxxSite`](#newlinesbeforeopenparenxxxsite).
+Requires [`align.closeParenSite`](#aligncloseparensite).
+
+> Since v3.3.2.
+
+```scala mdoc:defaults
+align.beforeOpenParenCallSite
+align.beforeOpenParenDefnSite
+```
+
 ### `align.stripMargin`
 
 See [assumeStandardLibraryStripMargin](#assumestandardlibrarystripmargin).
@@ -2068,6 +2081,9 @@ Additional nuances:
 - if the corresponding `align.openParenXxxSite` is true, multi-line parameters
   will start on the same line as the opening parenthesis and align; otherwise,
   formatting will use a newline and an appropriate continuation indent.
+- if the corresponding [`align.beforeOpenParenXxxSite`](#alignbeforeopenparenxxxsite)
+  is true, when the first parameter group starts without a line break, subsequent
+  parameter groups will be aligned to it.
 
 ```scala mdoc:defaults
 newlines.beforeOpenParenDefnSite

scalafmt-core/shared/src/main/scala/org/scalafmt/config/Align.scala

@@ -67,6 +67,8 @@ case class Align(
     private val openBracketDefnSite: Option[Boolean] = None,
     openParenDefnSite: Boolean = false,
     private[config] val openParenTupleSite: Option[Boolean] = None,
+    beforeOpenParenDefnSite: Boolean = false,
+    beforeOpenParenCallSite: Boolean = false,
     tokens: Seq[AlignToken] = Seq(AlignToken.caseArrow),
     arrowEnumeratorGenerator: Boolean = false,
     tokenCategory: Map[String, String] = Map(),

scalafmt-core/shared/src/main/scala/org/scalafmt/config/ScalafmtConfig.scala

@@ -415,6 +415,8 @@ object ScalafmtConfig {
       addIf(rewrite.insertBraces.minLines != 0 && rewrite.scala3.removeOptionalBraces == RemoveOptionalBraces.oldSyntaxToo)
       if (rewrite.insertBraces.minLines != 0 && rewrite.rules.contains(RedundantBraces))
         addIf(rewrite.insertBraces.minLines < rewrite.redundantBraces.maxBreaks)
+      addIf(align.beforeOpenParenDefnSite && !align.closeParenSite)
+      addIf(align.beforeOpenParenCallSite && !align.closeParenSite)
     }
     // scalafmt: {}
     if (allErrors.isEmpty) Configured.ok(cfg)

scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatOps.scala

@@ -1600,7 +1600,7 @@ class FormatOps(
 
       private def getOpenNLByTree(
           fun: Tree,
-          argsOrArgss: Either[Seq[Tree], Seq[Seq[Tree]]],
+          argsOrArgss: CallArgs,
           penalty: Int
       ): Seq[Policy] = {
         val argss = argsOrArgss match {

scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala

@@ -1,7 +1,7 @@
 package org.scalafmt.internal
 
 import org.scalafmt.Error.UnexpectedTree
-import org.scalafmt.config.BinPack
+import org.scalafmt.config.{Align, BinPack}
 import org.scalafmt.config.{ImportSelectors, Newlines, ScalafmtConfig, Spaces}
 import org.scalafmt.internal.ExpiresOn.{After, Before}
 import org.scalafmt.internal.Length.{Num, StateColumn}
@@ -622,11 +622,17 @@ class Router(formatOps: FormatOps) {
         val beforeDefRhs = defRhs.flatMap(tokens.tokenJustBeforeOpt)
         def getSplitsBeforeOpenParen(
             src: Newlines.SourceHints,
-            indentLen: Int
-        ) = {
+            indentLen: Int,
+            shouldAlignBefore: Align => Boolean
+        )(getArgsOpt: => Option[Seq[Tree]]) = {
           val close = matching(open)
           val indent = Indent(indentLen, close, ExpiresOn.After)
-          src match {
+          val isAlignFirstParen = shouldAlignBefore(style.align) &&
+            !prevNonComment(ft).left.is[T.RightParen]
+          def noSplitSplit(implicit fileLine: FileLine) =
+            if (isAlignFirstParen) Split(NoSplit, 0)
+            else Split(NoSplit, 0).withSingleLine(close)
+          val splits = src match {
             case Newlines.unfold =>
               val slbEnd =
                 if (defn) beforeDefRhs.fold(getLastToken(rightOwner))(_.left)
@@ -657,7 +663,7 @@ class Router(formatOps: FormatOps) {
                 Seq(Split(Newline, 0).withIndent(indent))
               else
                 Seq(
-                  Split(NoSplit, 0).withSingleLine(close),
+                  noSplitSplit,
                   Split(Newline, 1).withIndent(indent)
                 )
             case _ =>
@@ -672,12 +678,22 @@ class Router(formatOps: FormatOps) {
                     }
                   }
               Seq(
-                Split(NoSplit, 0).withSingleLine(close),
+                noSplitSplit,
                 Split(Newline, 1)
                   .withIndent(indent)
                   .withPolicyOpt(nlColonPolicy)
               )
           }
+          val argsOpt = if (isAlignFirstParen) getArgsOpt else None
+          argsOpt.map(x => tokens.tokenAfter(x).right).fold(splits) { x =>
+            val noSplitIndents = Seq(
+              Indent(StateColumn, x, ExpiresOn.Before),
+              Indent(-indentLen, x, ExpiresOn.Before)
+            )
+            splits.map { s =>
+              if (s.isNL) s else s.withIndents(noSplitIndents)
+            }
+          }
         }
         val beforeOpenParenSplits =
           if (!open.is[T.LeftParen]) None
@@ -692,12 +708,31 @@ class Router(formatOps: FormatOps) {
                 style.indent.extraBeforeOpenParenDefnSite +
                   (if (ob) style.indent.getSignificant else style.indent.main)
               }
-              getSplitsBeforeOpenParen(x, indent)
+              getSplitsBeforeOpenParen(x, indent, _.beforeOpenParenDefnSite) {
+                rightOwner match {
+                  case SplitDefnIntoParts(_, _, _, args) => Some(args.last)
+                  case _ => None
+                }
+              }
             }
           else if (style.dialect.allowSignificantIndentation)
-            style.newlines.getBeforeOpenParenCallSite.map(
-              getSplitsBeforeOpenParen(_, style.indent.getSignificant)
-            )
+            style.newlines.getBeforeOpenParenCallSite.map { x =>
+              val indent = style.indent.getSignificant
+              @tailrec
+              def findLastCallArgs(tree: Tree, ca: CallArgs): CallArgs =
+                tree match {
+                  case SplitCallIntoParts(_, pca) =>
+                    tree.parent match {
+                      case Some(p) => findLastCallArgs(p, pca)
+                      case _ => pca
+                    }
+                  case _ => ca
+                }
+              getSplitsBeforeOpenParen(x, indent, _.beforeOpenParenCallSite) {
+                Option(findLastCallArgs(rightOwner, null))
+                  .map(_.fold(identity, _.last))
+              }
+            }
           else None
         beforeOpenParenSplits.getOrElse(Seq(Split(modification, 0)))
 

scalafmt-core/shared/src/main/scala/org/scalafmt/util/TreeOps.scala

@@ -472,7 +472,8 @@ object TreeOps {
       case _ => false
     }
 
-  type CallParts = (Tree, Either[Seq[Tree], Seq[Seq[Tree]]])
+  type CallArgs = Either[Seq[Tree], Seq[Seq[Tree]]]
+  type CallParts = (Tree, CallArgs)
   val splitCallIntoParts: PartialFunction[Tree, CallParts] = {
     case t: Term.Apply => (t.fun, Left(t.args))
     case t: Term.Super => (t, Left(Seq(t.superp)))

scalafmt-tests/src/test/resources/newlines/source_classic.stat

@@ -5679,3 +5679,34 @@ object a {
   }
   else doSomethingOtherwise()
 }
+<<< align.beforeOpenParenDefnSite
+maxColumn = 100
+align.closeParenSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}
+<<< align.beforeOpenParenDefnSite + align.openParenDefnSite
+maxColumn = 85
+danglingParentheses.defnSite = false
+align.closeParenSite = true
+align.openParenDefnSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String, partialFunctions: PartialFunction[options.Common, List[String]]*)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String,
+                partialFunctions: PartialFunction[options.Common, List[String]]*)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}

scalafmt-tests/src/test/resources/newlines/source_fold.stat

@@ -5438,3 +5438,34 @@ object a {
   }
   else doSomethingOtherwise()
 }
+<<< align.beforeOpenParenDefnSite
+maxColumn = 100
+align.closeParenSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}
+<<< align.beforeOpenParenDefnSite + align.openParenDefnSite
+maxColumn = 85
+danglingParentheses.defnSite = false
+align.closeParenSite = true
+align.openParenDefnSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String, partialFunctions: PartialFunction[options.Common, List[String]]*)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String,
+                partialFunctions: PartialFunction[options.Common, List[String]]*)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}

scalafmt-tests/src/test/resources/newlines/source_keep.stat

@@ -5698,3 +5698,33 @@ object a {
   }
   else doSomethingOtherwise()
 }
+<<< align.beforeOpenParenDefnSite
+maxColumn = 100
+align.closeParenSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {}
+<<< align.beforeOpenParenDefnSite + align.openParenDefnSite
+maxColumn = 85
+danglingParentheses.defnSite = false
+align.closeParenSite = true
+align.openParenDefnSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String, partialFunctions: PartialFunction[options.Common, List[String]]*)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching(versionString: String,
+                partialFunctions: PartialFunction[options.Common, List[String]]*)
+               (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}

scalafmt-tests/src/test/resources/newlines/source_unfold.stat

@@ -5949,3 +5949,36 @@ object a {
   else
     doSomethingOtherwise()
 }
+<<< align.beforeOpenParenDefnSite
+maxColumn = 100
+align.closeParenSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching
+  (versionString: String)
+  (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}
+<<< align.beforeOpenParenDefnSite + align.openParenDefnSite
+maxColumn = 85
+danglingParentheses.defnSite = false
+align.closeParenSite = true
+align.openParenDefnSite = true
+align.beforeOpenParenDefnSite = true
+newlines.beforeOpenParenDefnSite = source
+===
+def allMatching(versionString: String, partialFunctions: PartialFunction[options.Common, List[String]]*)
+                 (partialFunctions: PartialFunction[options.Common, List[String]]*): List[String] = {
+
+                 }
+>>>
+def allMatching
+  (versionString: String,
+   partialFunctions: PartialFunction[options.Common, List[String]]*)
+  (partialFunctions: PartialFunction[options.Common, List[String]]*)
+  : List[String] = {}

scalafmt-tests/src/test/resources/scala3/OptionalBraces.stat

@@ -3288,3 +3288,27 @@ object a:
    do matrix(x)(0) += matrix(x - 1)(0)
    while x < range
    do matrix(x)(0) += matrix(x - 1)(0)
+<<< align.beforeOpenParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString)
+                 (partialFunctions)
+>>>
+allMatching(versionString)
+           (partialFunctions)
+<<< align.beforeOpenParenCallSite + align.openParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.openParenCallSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString, partialFunctions)
+                 (partialFunctions)
+>>>
+allMatching(versionString,
+            partialFunctions
+           )(partialFunctions)

scalafmt-tests/src/test/resources/scala3/OptionalBraces_fold.stat

@@ -3131,3 +3131,27 @@ object a:
       matrix(x)(0) += matrix(x - 1)(0)
    while x < range do
       matrix(x)(0) += matrix(x - 1)(0)
+<<< align.beforeOpenParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString)
+                 (partialFunctions)
+>>>
+allMatching(versionString)
+           (partialFunctions)
+<<< align.beforeOpenParenCallSite + align.openParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.openParenCallSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString, partialFunctions)
+                 (partialFunctions)
+>>>
+allMatching(versionString,
+            partialFunctions
+           )(partialFunctions)

scalafmt-tests/src/test/resources/scala3/OptionalBraces_keep.stat

@@ -3276,3 +3276,28 @@ object a:
       x < range
    do
       matrix(x)(0) += matrix(x - 1)(0)
+<<< align.beforeOpenParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString)
+                 (partialFunctions)
+>>>
+allMatching(versionString)
+           (partialFunctions)
+<<< align.beforeOpenParenCallSite + align.openParenCallSite
+maxColumn = 30
+align.closeParenSite = true
+align.openParenCallSite = true
+align.beforeOpenParenCallSite = true
+newlines.beforeOpenParenCallSite = source
+===
+allMatching(versionString, partialFunctions)
+                 (partialFunctions)
+>>>
+allMatching(versionString,
+            partialFunctions
+           )
+           (partialFunctions)