BestFirstSearch: if failed without a solution, retry without optimization

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

@@ -45,10 +45,9 @@ private class BestFirstSearch private (
   val noOptimizations = noOptimizationZones(tree)
   var explored = 0
   var deepestYet = State.start
-  var statementCount = 0
   val best = mutable.Map.empty[Int, State]
-  var pathologicalEscapes = 0
   val visits = new Array[Int](tokens.length)
+  var keepSlowStates = !pruneSlowStates
 
   type StateHash = Long
 
@@ -60,17 +59,11 @@ private class BestFirstSearch private (
   /**
     * Returns true if it's OK to skip over state.
     */
-  def shouldEnterState(curr: State): Boolean = {
-    val splitToken = tokens(curr.depth)
-    val insideOptimizationZone =
-      curr.policy.noDequeue || isInsideNoOptZone(splitToken)
-    def hasBestSolution = !pruneSlowStates || insideOptimizationZone || {
+  def shouldEnterState(curr: State): Boolean =
+    keepSlowStates || curr.policy.noDequeue ||
+      isInsideNoOptZone(tokens(curr.depth)) ||
       // TODO(olafur) document why/how this optimization works.
-      val result = !best.get(curr.depth).exists(_.alwaysBetter(curr))
-      result
-    }
-    hasBestSolution
-  }
+      !best.get(curr.depth).exists(_.alwaysBetter(curr))
 
   def shouldRecurseOnBlock(
       ft: FormatToken,
@@ -208,7 +201,7 @@ private class BestFirstSearch private (
           var optimalNotFound = true
           actualSplit.foreach { split =>
             val nextState = curr.next(style, split, splitToken)
-            if (depth == 0 && split.modification.isNewline &&
+            if (!keepSlowStates && depth == 0 && split.modification.isNewline &&
               !best.contains(curr.depth)) {
               best.update(curr.depth, nextState)
             }
@@ -254,7 +247,16 @@ private class BestFirstSearch private (
   }
 
   def getBestPath: SearchResult = {
-    val state = shortestPath(State.start, tree.tokens.last)
+    val state = {
+      def run = shortestPath(State.start, tree.tokens.last)
+      val state = run
+      if (null != state) state
+      else {
+        best.clear()
+        keepSlowStates = true
+        run
+      }
+    }
     if (null != state) {
       runner.event(CompleteFormat(explored, state))
       SearchResult(state, reachedEOF = true)

scalafmt-tests/src/test/resources/align/DefaultWithAlign.stat

@@ -483,3 +483,73 @@ object x {
   // comment
   println("foo") // comment
 }
+<<< #1720 original, two SL comments
+type iovec = CStruct2[Ptr[Byte], // iov_base
+                        CSize] // iov_len
+>>>
+type iovec = CStruct2[
+  Ptr[Byte], // iov_base
+  CSize
+] // iov_len
+<<< #1720 with val
+val iovec = CStruct2[Ptr[Byte], // iov_base
+                        CSize](a) // iov_len
+>>>
+val iovec = CStruct2[
+  Ptr[Byte], // iov_base
+  CSize
+](a) // iov_len
+<<< #1720 no align
+align = none
+===
+type iovec = CStruct2[Ptr[Byte], // iov_base
+                        CSize] // iov_len
+>>>
+type iovec = CStruct2[
+  Ptr[Byte], // iov_base
+  CSize
+] // iov_len
+<<< #1720 second SL comment
+type iovec = CStruct2[Ptr[Byte],
+                        CSize] // iov_len
+>>>
+type iovec = CStruct2[Ptr[Byte], CSize] // iov_len
+<<< #1720 first SL comment
+type iovec = CStruct2[Ptr[Byte], // iov_base
+                        CSize]
+>>>
+type iovec = CStruct2[
+  Ptr[Byte], // iov_base
+  CSize
+]
+<<< #1720 nested multi-arg type with two SL comments
+type iovec = CStruct2[Ptr[Byte, // iov_base
+                        CSize]] // iov_len
+>>>
+type iovec = CStruct2[Ptr[
+  Byte, // iov_base
+  CSize
+]] // iov_len
+<<< #1720 one arg with SL comment
+type iovec = CStruct2[Ptr[Byte] // iov_base
+                        ]
+>>>
+type iovec = CStruct2[
+  Ptr[Byte] // iov_base
+]
+<<< #1720 first inline comment
+type iovec = CStruct2[Ptr[Byte], /* iov_base */
+                        CSize]
+>>>
+type iovec = CStruct2[
+  Ptr[Byte], /* iov_base */
+  CSize
+]
+<<< #1720 first inline comment with apply
+val iovec = CStruct2(Ptr(Byte), /* iov_base */
+                        CSize)
+>>>
+val iovec = CStruct2(
+  Ptr(Byte), /* iov_base */
+  CSize
+)