Router: binpack defn single-line to avoid overflow

The current rule could occasionally lead to overflow since it didn't use a killall (remove path on failure) optimal token, and then would arrive at a point where other viable alternatives would have been set aside.
scalameta · Dec 28, 2021 · d527e84 · d527e84
1 parent 4054630
commit d527e84
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Showing 3 changed files with 11 additions and 11 deletions.
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala
@@ -1101,9 +1101,9 @@ class Router(formatOps: FormatOps) {
           val mustDangle = onlyConfigStyle ||
             style.danglingParentheses.defnSite &&
             (style.newlines.sourceIgnored || !style.optIn.configStyleArguments)
+          val slbOnly = mustDangle || style.newlines.source.eq(Newlines.unfold)
           def noSplitPolicy: Policy =
-            if (mustDangle || style.newlines.source.eq(Newlines.unfold))
-              slbPolicy
+            if (slbOnly) slbPolicy
             else {
               val penalizeOpens = bracketPenalty.fold(Policy.noPolicy) { p =>
                 Policy.before(close) {
@@ -1132,11 +1132,11 @@ class Router(formatOps: FormatOps) {
           def nlCost = bracketPenalty.getOrElse(1)
 
           Seq(
-            Split(noSplitModification, 0)
-              .notIf(mustUseNL)
+            Split(mustUseNL, 0)(noSplitModification)
+              .withOptimalToken(close, ignore = !slbOnly, killOnFail = true)
               .withPolicy(noSplitPolicy)
               .withIndents(noSplitIndents),
-            Split(nlMod, if (mustUseNL) 0 else nlCost)
+            Split(nlMod, if (mustUseNL || slbOnly) 0 else nlCost)
               .withPolicy(nlDanglePolicy & onelinePolicy & penalizeBrackets)
               .withIndent(indent)
           )

diff --git a/scalafmt-tests/src/test/resources/newlines/source_fold.stat b/scalafmt-tests/src/test/resources/newlines/source_fold.stat
@@ -4382,9 +4382,9 @@ object a {
 }
 >>>
 object a {
-  def foo(
-      bb: BB, cc: CC, dd: DD = DDD.ddd
-  ): Bar[Baz] = {
+  def foo(bb: BB, cc: CC, dd: DD = DDD.ddd): Bar[
+    Baz
+  ] = {
     // c
     qux
   }

diff --git a/scalafmt-tests/src/test/resources/newlines/source_unfold.stat b/scalafmt-tests/src/test/resources/newlines/source_unfold.stat
@@ -4807,9 +4807,9 @@ object a {
 }
 >>>
 object a {
-  def foo(
-      bb: BB, cc: CC, dd: DD = DDD.ddd
-  ): Bar[Baz] = {
+  def foo(bb: BB, cc: CC, dd: DD = DDD.ddd): Bar[
+    Baz
+  ] = {
     // c
     qux
   }