FormatOps: handle fewer braces and refined types

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

@@ -2037,6 +2037,36 @@ class FormatOps(
               def splits = Some(getSplits(ft, t, forceNL = true))
               def rightBrace = if (isSeqMulti(t.stats)) treeLast(t) else None
             })
+          case t: Type.Refine =>
+            Some(new OptionalBracesRegion {
+              def owner = Some(t)
+              def splits = Some(getSplits(ft, t, forceNL = true))
+              def rightBrace = treeLast(t)
+            })
+          case t: Term.ArgClause if tokens.getHead(t) eq ft =>
+            def funcSplit(arg: Term.FunctionTerm)(implicit fl: FileLine) = {
+              val end = tokens.getLast(arg)
+              val opt = getOptimalTokenFor(getFuncArrow(arg).getOrElse(end))
+              val indent = Num(style.indent.getSignificant - style.indent.main)
+              Split(Space, 0)
+                .withSingleLine(opt)
+                .andPolicy(decideNewlinesOnlyAfterToken(opt))
+                .withIndent(indent, end.left, ExpiresOn.After)
+            }
+            Some(new OptionalBracesRegion {
+              def owner = t.parent
+              def splits = Some(t.values match {
+                case (tf: Term.FunctionTerm) :: Nil
+                    if !style.newlines.alwaysBeforeCurlyLambdaParams &&
+                      t.parent.exists(_.is[Term.Apply]) =>
+                  getSplits(ft, t, forceNL = false) match {
+                    case s +: rs if !s.isNL => funcSplit(tf)(s.fileLine) +: rs
+                    case ss => ss
+                  }
+                case _ => getSplits(ft, t, forceNL = true)
+              })
+              def rightBrace = treeLast(t)
+            })
           case _ => None
         }
     }

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

@@ -1844,13 +1844,28 @@ class Router(formatOps: FormatOps) {
             }
 
           case Newlines.fold =>
-            val end =
-              nextSelect.fold(expire)(x => getLastNonTrivialToken(x.qual))
-            def exclude = insideBracesBlock(t, end, true)
-            Seq(
-              Split(NoSplit, 0).withSingleLine(end, exclude),
-              Split(NewlineT(alt = Some(NoSplit)), 1)
-            )
+            nextSelect match {
+              case Some(ns) if (ns.qual match {
+                    case p: Term.Apply if dialect.allowFewerBraces =>
+                      p.argClause.tokens.head.is[T.Colon]
+                    case p: Term.Match =>
+                      !tokenBefore(p.cases).left.is[T.LeftBrace]
+                    case _ => false
+                  }) =>
+                val nextDot = tokenBefore(ns.nameToken).left
+                Seq(
+                  Split(Newline, 0)
+                    .withPolicy(decideNewlinesOnlyBeforeClose(nextDot))
+                )
+              case _ =>
+                val end =
+                  nextSelect.fold(expire)(x => getLastNonTrivialToken(x.qual))
+                def exclude = insideBracesBlock(t, end, true)
+                Seq(
+                  Split(NoSplit, 0).withSingleLine(end, exclude),
+                  Split(NewlineT(alt = Some(NoSplit)), 1)
+                )
+            }
         }
 
         val delayedBreakPolicyOpt = nextSelect.map { selectLike =>

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

@@ -3606,12 +3606,10 @@ object a:
     List(1, 2, 3).foldLeft(1):
       case (a, b) => a + b
 >>>
-test does not parse
 object a:
    def f(): Unit =
      List(1, 2, 3).foldLeft(1):
-     case (a, b) => a + b
-     ^
+        case (a, b) => a + b
 <<< coloneol in fewer braces 2
 maxColumn = 80
 ===
@@ -3622,12 +3620,13 @@ object a:
     .apply:
       12 + 3
 >>>
-test does not parse
 object a:
    def f(): Unit =
      List(1, 2, 3)
-       .foo: a => a + 2
-               ^
+       .foo: a =>
+          a + 2
+       .apply:
+          12 + 3
 <<< coloneol in fewer braces 3
 maxColumn = 80
 ===
@@ -3638,12 +3637,12 @@ object a:
        case _ =>
     otherTerm()
 >>>
-test does not parse
 object a:
    def f(): Unit =
       List(1, 2, 3).foo:
-      case a: Int =>
-      ^
+         case a: Int =>
+         case _      =>
+      otherTerm()
 <<< match with eol
 maxColumn = 80
 ===
@@ -3654,30 +3653,29 @@ object a:
     .apply:
       12 + 3
 >>>
-UNABLE TO FORMAT,
-tok=2∙.[77:86]
+object a:
+   def f(): Unit =
+     List(1, 2, 3).match
         case _ => a + 2
-                      ^
+       .apply:
+          12 + 3
 <<< coloneol in refined types
 maxColumn = 80
 ===
 object a:
   type T = String:
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String:
-                  ^
+      type U = Int
 <<< with in refined types
 maxColumn = 80
 ===
 object a:
   type T = String with
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String with
-   type U = Int
-   ^
+      type U = Int

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

@@ -3432,9 +3432,8 @@ object a:
       case (a, b) => a + b
 >>>
 object a:
-   def f(): Unit = List(1, 2, 3)
-     .foldLeft(1):
-     case (a, b) => a + b
+   def f(): Unit = List(1, 2, 3).foldLeft(1):
+      case (a, b) => a + b
 <<< coloneol in fewer braces 2
 maxColumn = 80
 ===
@@ -3445,10 +3444,12 @@ object a:
     .apply:
       12 + 3
 >>>
-test does not parse
 object a:
-   def f(): Unit = List(1, 2, 3).foo: a => a + 2.apply: 12 + 2
-                                                ^
+   def f(): Unit = List(1, 2, 3)
+     .foo: a =>
+        a + 2
+     .apply:
+        12 + 3
 <<< coloneol in fewer braces 3
 maxColumn = 80
 ===
@@ -3459,12 +3460,12 @@ object a:
        case _ =>
     otherTerm()
 >>>
-Idempotency violated
 object a:
-   def f(): Unit = List(1, 2, 3)
-     .foo:
-     case a: Int =>
-     case _      => otherTerm()
+   def f(): Unit =
+      List(1, 2, 3).foo:
+         case a: Int =>
+         case _      =>
+      otherTerm()
 <<< match with eol
 maxColumn = 80
 ===
@@ -3476,29 +3477,28 @@ object a:
       12 + 3
 >>>
 object a:
-   def f(): Unit = List(1, 2, 3).match
-      case _ => a + 2
-     .apply: 12 + 3
+   def f(): Unit = List(1, 2, 3)
+     .match
+        case _ => a + 2
+     .apply:
+        12 + 3
 <<< coloneol in refined types
 maxColumn = 80
 ===
 object a:
   type T = String:
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String:
-                  ^
+      type U = Int
 <<< with in refined types
 maxColumn = 80
 ===
 object a:
   type T = String with
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String with
-   type U = Int
-   ^
+      type U = Int

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

@@ -3588,12 +3588,10 @@ object a:
     List(1, 2, 3).foldLeft(1):
       case (a, b) => a + b
 >>>
-test does not parse
 object a:
    def f(): Unit =
      List(1, 2, 3).foldLeft(1):
-     case (a, b) => a + b
-     ^
+        case (a, b) => a + b
 <<< coloneol in fewer braces 2
 maxColumn = 80
 ===
@@ -3604,12 +3602,12 @@ object a:
     .apply:
       12 + 3
 >>>
-Idempotency violated
 object a:
    def f(): Unit =
      List(1, 2, 3).foo: a =>
-       a + 2
-         .apply: 12 + 2
+        a + 2
+       .apply:
+          12 + 3
 <<< coloneol in fewer braces 3
 maxColumn = 80
 ===
@@ -3620,12 +3618,12 @@ object a:
        case _ =>
     otherTerm()
 >>>
-test does not parse
 object a:
    def f(): Unit =
       List(1, 2, 3).foo:
-      case a: Int =>
-      ^
+         case a: Int =>
+         case _      =>
+      otherTerm()
 <<< match with eol
 maxColumn = 80
 ===
@@ -3640,27 +3638,25 @@ object a:
    def f(): Unit =
      List(1, 2, 3).match
         case _ => a + 2
-       .apply: 12 + 3
+       .apply:
+          12 + 3
 <<< coloneol in refined types
 maxColumn = 80
 ===
 object a:
   type T = String:
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String:
-                  ^
+      type U = Int
 <<< with in refined types
 maxColumn = 80
 ===
 object a:
   type T = String with
     type U = Int
 >>>
-test does not parse
 object a:
    type T = String with
-   type U = Int
-   ^
+      type U = Int