json_runtime_error.scala

val json = Json.obj("users" -> Json.arr(Json.obj("name" -> "martin"), Json.obj("name" -> "dupont")))
val path = ((__ \ "users")(1) \ "name")
__.json.update(path.json.put(JsString("toto"))).reads(json)

stacktrace

scala> __.json.update(((__ \ "users")(1) \ "name").json.put(JsString(""))).reads(json)
java.lang.RuntimeException: expected KeyPathNode
	at play.api.libs.json.JsPath$.step$1(JsPath.scala:148)
	at play.api.libs.json.JsPath$.step$1(JsPath.scala:147)
	at play.api.libs.json.JsPath$.play$api$libs$json$JsPath$$buildSubPath$1(JsPath.scala:153)
	at play.api.libs.json.JsPath$$anonfun$createObj$1.apply(JsPath.scala:158)
	at play.api.libs.json.JsPath$$anonfun$createObj$1.apply(JsPath.scala:156)
	at scala.collection.IndexedSeqOptimized$class.foldl(IndexedSeqOptimized.scala:51)
	at scala.collection.IndexedSeqOptimized$class.foldLeft(IndexedSeqOptimized.scala:60)
	at scala.collection.mutable.WrappedArray.foldLeft(WrappedArray.scala:34)
	at play.api.libs.json.JsPath$.createObj(JsPath.scala:156)
	at play.api.libs.json.PathReads$$anonfun$jsPut$1.apply(JsConstraints.scala:73)
	at play.api.libs.json.PathReads$$anonfun$jsPut$1.apply(JsConstraints.scala:73)
	at play.api.libs.json.Reads$$anon$8.reads(Reads.scala:98)
	at play.api.libs.json.PathReads$$anonfun$jsUpdate$1$$anonfun$apply$14.apply(JsConstraints.scala:82)
	at play.api.libs.json.PathReads$$anonfun$jsUpdate$1$$anonfun$apply$14.apply(JsConstraints.scala:82)
	at play.api.libs.json.JsResult$class.flatMap(JsResult.scala:97)
	at play.api.libs.json.JsSuccess.flatMap(JsResult.scala:6)
	at play.api.libs.json.PathReads$$anonfun$jsUpdate$1.apply(JsConstraints.scala:82)
	at play.api.libs.json.PathReads$$anonfun$jsUpdate$1.apply(JsConstraints.scala:79)
	at play.api.libs.json.Reads$$anon$8.reads(Reads.scala:98)
	at .<init>(<console>:12)
	at .<clinit>(<console>)
	at .<init>(<console>:7)
	at .<clinit>(<console>)
	at $print(<console>)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at scala.tools.nsc.interpreter.IMain$ReadEvalPrint.call(IMain.scala:734)
	at scala.tools.nsc.interpreter.IMain$Request.loadAndRun(IMain.scala:983)
	at scala.tools.nsc.interpreter.IMain.loadAndRunReq$1(IMain.scala:573)
	at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:604)
	at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:568)
	at scala.tools.nsc.interpreter.ILoop.reallyInterpret$1(ILoop.scala:745)
	at scala.tools.nsc.interpreter.ILoop.interpretStartingWith(ILoop.scala:790)
	at scala.tools.nsc.interpreter.ILoop.command(ILoop.scala:702)
	at scala.tools.nsc.interpreter.ILoop.processLine$1(ILoop.scala:566)
	at scala.tools.nsc.interpreter.ILoop.innerLoop$1(ILoop.scala:573)
	at scala.tools.nsc.interpreter.ILoop.loop(ILoop.scala:576)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:867)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822)
	at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135)
	at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:822)
	at scala.tools.nsc.interpreter.ILoop.main(ILoop.scala:889)
	at xsbt.ConsoleInterface.run(ConsoleInterface.scala:69)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:102)
	at sbt.compiler.AnalyzingCompiler.console(AnalyzingCompiler.scala:77)
	at sbt.Console.sbt$Console$$console0$1(Console.scala:23)
	at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply$mcV$sp(Console.scala:24)
	at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply(Console.scala:24)
	at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply(Console.scala:24)
	at sbt.Logger$$anon$4.apply(Logger.scala:90)
	at sbt.TrapExit$App.run(TrapExit.scala:244)
	at java.lang.Thread.run(Thread.java:745)