SearchStateExploded exception

[poslegm]

This template is a guideline, not a strict requirement.

• Version: 2.1.1
• Integration: anything
• Configuration:

version = 2.1.1

Steps

Given code like this:

object a {
@tailrec
  final def rhsOptimalToken(start: FormatToken): Token = start.right match {
      case T.Comma() | T.LeftParen() | T.RightParen() | T.RightBracket() |
          T.Semicolon() | T.RightArrow() | T.Equals()
          if next(start) != start &&
            !startsNewBlock(start.right) &&
            newlinesBetween(start.between) == 0 =>
        rhsOptimalToken(next(start))
      case _ => start.left
    }
}

When I run scalafmt like this:

scalafmt --stdin

Problem

Scalafmt formats code like this:

org.scalafmt.cli.FailedToFormat: stdin.scala
Caused by: org.scalafmt.Error$SearchStateExploded: Search state exploded around line 6
        at org.scalafmt.internal.BestFirstSearch.shortestPath(BestFirstSearch.scala:219)
        at org.scalafmt.internal.BestFirstSearch.getBestPath(BestFirstSearch.scala:277)
        at org.scalafmt.Scalafmt$.format(Scalafmt.scala:63)
        at org.scalafmt.cli.ScalafmtCoreRunner$.unsafeHandleFile(ScalafmtCoreRunner.scala:85)
        at org.scalafmt.cli.ScalafmtCoreRunner$.handleFile(ScalafmtCoreRunner.scala:64)
        at org.scalafmt.cli.ScalafmtCoreRunner$.$anonfun$run$3(ScalafmtCoreRunner.scala:42)
        at org.scalafmt.cli.ScalafmtCoreRunner$.$anonfun$run$3$adapted(ScalafmtCoreRunner.scala:41)
        at scala.collection.Iterator.foreach(Iterator.scala:941)
        at scala.collection.Iterator.foreach$(Iterator.scala:941)
        at scala.collection.AbstractIterator.foreach(Iterator.scala:1429)
        at scala.collection.parallel.ParIterableLike$Foreach.leaf(ParIterableLike.scala:974)
        at scala.collection.parallel.Task.$anonfun$tryLeaf$1(Tasks.scala:53)
        at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
        at scala.util.control.Breaks$$anon$1.catchBreak(Breaks.scala:67)
        at scala.collection.parallel.Task.tryLeaf(Tasks.scala:56)
        at scala.collection.parallel.Task.tryLeaf$(Tasks.scala:50)
        at scala.collection.parallel.ParIterableLike$Foreach.tryLeaf(ParIterableLike.scala:971)
        at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask.compute(Tasks.scala:153)
        at scala.collection.parallel.AdaptiveWorkStealingTasks$WrappedTask.compute$(Tasks.scala:149)
        at scala.collection.parallel.AdaptiveWorkStealingForkJoinTasks$WrappedTask.compute(Tasks.scala:440)
        at java.base/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:189)
        at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
        at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
        at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
        at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
        at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:177)

Expectation

Scalafmt doesn't fail

Notes

Braces around function body solves the issue:

object a {
 @tailrec
  final def rhsOptimalToken(start: FormatToken): Token = {
    start.right match {
      case T.Comma() | T.LeftParen() | T.RightParen() | T.RightBracket() | T.Semicolon() |
           T.RightArrow() | T.Equals()
          if next(start) != start &&
            !startsNewBlock(start.right) &&
            newlinesBetween(start.between) == 0 =>
        rhsOptimalToken(next(start))
      case _ => start.left
    }
  }
}

And this code formats fine:

object a {
@tailrec
  final def rhsOptimalToken(start: FormatToken): Token = start.right match {
      case Comma() | LeftParen() | RightParen() | RightBracket() |
          Semicolon() | RightArrow() | Equals()
          if next(start) != start &&
            !startsNewBlock(start.right) &&
            newlinesBetween(start.between) == 0 =>
        rhsOptimalToken(next(start))
      case _ => start.left
    }
}

[yoohaemin]

I just hit the exact same problem, thank you @poslegm for the workaround.

[ekrich]

Here is an additional file that won't format from Scala Native. This has not formatted for as long as I can remember. Using 2.2.1 at this time.

$ scripts/scalafmt
org.scalafmt.cli.FailedToFormat: /Users/eric/workspace/scala-native/nscplugin/src/main/scala/scala/scalanative/nscplugin/NirGenExpr.scala
Caused by: org.scalafmt.Error$SearchStateExploded: Search state exploded around line 1271

[ekrich]

Also, this previously in 1.5.1 was a Warning with no stack trace which I think is more appropriate if the user does not have much control over the error/warning.

[warn] Error in /home/travis/build/scala-native/scala-native/nscplugin/src/main/scala/scala/scalanative/nscplugin/NirGenExpr.scala: 
org.scalafmt.Error$SearchStateExploded: Search state exploded around line 1271

[poslegm]

Looks like it works fine on master. Will see after 2.5.0-RC1 release