NullPointerException with wartremover plugin

[avdv]

(See the guidelines for contributing, linked above)

steps

We're using the wartremover 1.1.1 SBT plugin in a Play 2.5.8 application, with SBT 0.13.12 and ReactiveMongo.

Sorry, but giving a reproduction is a bit hard since it seems to depend on a lot of preliminaries and we just hit this after refactoring code into different packages.

Basically, we just ran sbt compile in our project.

problem

An NPE is thrown when the wartremover plugin is trying to report an issue:

java.lang.NullPointerException
        at play.routes.compiler.RoutesCompiler$GeneratedSource$.unapply(RoutesCompiler.scala:37)
        at play.sbt.routes.RoutesCompiler$$anonfun$11$$anonfun$apply$2.isDefinedAt(RoutesCompiler.scala:180)
        at play.sbt.routes.RoutesCompiler$$anonfun$11$$anonfun$apply$2.isDefinedAt(RoutesCompiler.scala:179)
        at scala.Option.collect(Option.scala:250)
        at play.sbt.routes.RoutesCompiler$$anonfun$11.apply(RoutesCompiler.scala:179)
        at play.sbt.routes.RoutesCompiler$$anonfun$11.apply(RoutesCompiler.scala:178)
        at sbt.Compiler$$anonfun$foldMappers$2$$anonfun$apply$1.apply(Compiler.scala:156)
        at sbt.Compiler$$anonfun$foldMappers$2$$anonfun$apply$1$$anonfun$apply$2.apply(Compiler.scala:156)
        at scala.Option.getOrElse(Option.scala:120)
        at sbt.Compiler$$anonfun$foldMappers$2$$anonfun$apply$1.apply(Compiler.scala:156)
[15]  at sbt.LoggerReporter.log(LoggerReporter.scala:109)
        at xsbt.DelegatingReporter.info0(DelegatingReporter.scala:38)
        at xsbt.DelegatingReporter.info0(DelegatingReporter.scala:17)
        at scala.reflect.internal.Reporter.warning(Reporting.scala:81)
        at org.wartremover.Plugin$Traverser$$anon$1$$anon$2.error(Plugin.scala:68)
        at org.wartremover.Plugin$Traverser$$anon$1$$anon$2.error(Plugin.scala:65)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:49)
        at scala.reflect.api.Trees$Traverser.traverseTrees(Trees.scala:2484)
        at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1234)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1330)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.internal.Trees$$anonfun$traverseMemberDef$1$1.apply$mcV$sp(Trees.scala:1215)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.internal.Trees$class.traverseMemberDef$1(Trees.scala:1203)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1328)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.api.Trees$Traverser$$anonfun$traverseStats$1$$anonfun$apply$1.apply$mcV$sp(Trees.scala:2498)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.api.Trees$Traverser.traverseStats(Trees.scala:2497)
        at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1232)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1330)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.internal.Trees$$anonfun$traverseMemberDef$1$1.apply$mcV$sp(Trees.scala:1207)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.internal.Trees$class.traverseMemberDef$1(Trees.scala:1203)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1328)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.api.Trees$Traverser.traverseTrees(Trees.scala:2484)
        at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1234)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1330)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.internal.Trees$$anonfun$traverseMemberDef$1$1.apply$mcV$sp(Trees.scala:1209)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.internal.Trees$class.traverseMemberDef$1(Trees.scala:1203)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1328)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.api.Trees$Traverser$$anonfun$traverseStats$1$$anonfun$apply$1.apply$mcV$sp(Trees.scala:2498)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.api.Trees$Traverser.traverseStats(Trees.scala:2497)
        at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1232)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1330)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.internal.Trees$$anonfun$traverseMemberDef$1$1.apply$mcV$sp(Trees.scala:1208)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.internal.Trees$class.traverseMemberDef$1(Trees.scala:1203)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1327)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at scala.reflect.api.Trees$Traverser$$anonfun$traverseStats$1$$anonfun$apply$1.apply$mcV$sp(Trees.scala:2498)
        at scala.reflect.api.Trees$Traverser.atOwner(Trees.scala:2507)
        at scala.reflect.api.Trees$Traverser.traverseStats(Trees.scala:2497)
        at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1326)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
        at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
        at org.wartremover.warts.Var$$anon$1.traverse(Var.scala:52)
        at org.wartremover.Plugin$Traverser$$anon$1$$anonfun$go$1$1.apply(Plugin.scala:74)
        at org.wartremover.Plugin$Traverser$$anon$1$$anonfun$go$1$1.apply(Plugin.scala:74)
        at scala.collection.immutable.List.foreach(List.scala:381)
        at org.wartremover.Plugin$Traverser$$anon$1.go$1(Plugin.scala:74)
        at org.wartremover.Plugin$Traverser$$anon$1.apply(Plugin.scala:77)
        at scala.tools.nsc.Global$GlobalPhase$$anonfun$applyPhase$1.apply$mcV$sp(Global.scala:440)
        at scala.tools.nsc.Global$GlobalPhase.withCurrentUnit(Global.scala:431)
        at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:440)
        at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:398)
        at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:398)
        at scala.collection.Iterator$class.foreach(Iterator.scala:893)
        at scala.collection.AbstractIterator.foreach(Iterator.scala:1336)
        at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:398)
        at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1501)
        at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1486)
        at scala.tools.nsc.Global$Run.compileSources(Global.scala:1481)
        at scala.tools.nsc.Global$Run.compile(Global.scala:1582)
        at xsbt.CachedCompiler0.run(CompilerInterface.scala:116)
        at xsbt.CachedCompiler0.run(CompilerInterface.scala:95)
...

This seems be caused by the Position having no sourceFile attached, as JDB yields the following result at sbt.LoggerReporter.log (LoggerReporter.scala:109):

pool-4-thread-4[15] eval pos.toString()
 pos.toString() = "<macro>:1"
[15] eval pos.sourceFile.isEmpty()
 pos.sourceFile.isEmpty() = false
[15] eval pos.sourceFile.get()
 pos.sourceFile.get() = null

So, apparently the posIn parameter given to convert here is already missing that information.

expectation

no exception.

[avdv]

closing since fixes are already merged