Error "Can't unambiguously select between fixed arity signatures" when trying to run v13.2

When i tried to compile and run scriptcraft with v 13.2, it throw an error (see later) I tried to do some more investigation but without success - it is from lib/scriptcraft.js which is requiring js-patch and unit-testing setTimeout method.

Any possibility to fix it ? Thank you…

[21:00:50 INFO]: [scriptcraft] Enabling scriptcraft v3.3.0-2017-10-15
[21:00:52 ERROR]: [scriptcraft] Error evaluating scriptcraft\lib\scriptcraft.js: java.lang.NoSuchMethodException: Can't unambiguously select between fixed arity signatures [(org.bukkit.plugin.Plugin, java.util.function.Consumer, long), (org.bukkit.plugin.Plugin, java.lang.Runnable, long)] of the method org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftScheduler.runTaskLater for argument types [org.scriptcraftjs.bukkit.ScriptCraftPlugin, jdk.nashorn.internal.runtime.ScriptFunction, java.lang.Double]
[21:00:52 WARN]: java.lang.NoSuchMethodException: Can't unambiguously select between fixed arity signatures [(org.bukkit.plugin.Plugin, java.util.function.Consumer, long), (org.bukkit.plugin.Plugin, java.lang.Runnable, long)] of the method org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftScheduler.runTaskLater for argument types [org.scriptcraftjs.bukkit.ScriptCraftPlugin, jdk.nashorn.internal.runtime.ScriptFunction, java.lang.Double]
[21:00:52 WARN]:        at jdk.internal.dynalink.beans.OverloadedMethod.throwAmbiguousMethod(OverloadedMethod.java:225)
[21:00:52 WARN]:        at jdk.nashorn.internal.scripts.Script$Recompilation$32$158AI$\^eval\_.L:1#bukkitSetTimeout(<eval>:5)
[21:00:52 WARN]:        at jdk.nashorn.internal.scripts.Script$Recompilation$31$1905A$\^eval\_.L:1#exports#unitTest(<eval>:57)
[21:00:52 WARN]:        at jdk.nashorn.internal.scripts.Script$Recompilation$5$16346AAA$\^eval\_.__onEnable(<eval>:754)
[21:00:52 WARN]:        at jdk.nashorn.internal.scripts.Script$Recompilation$2$1583AAA$\^eval\_.L:5#__scboot(<eval>:90)
[21:00:52 WARN]:        at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:643)
[21:00:52 WARN]:        at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:494)
[21:00:52 WARN]:        at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
[21:00:52 WARN]:        at jdk.nashorn.api.scripting.ScriptObjectMirror.callMember(ScriptObjectMirror.java:199)
[21:00:52 WARN]:        at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:386)
[21:00:52 WARN]:        at jdk.nashorn.api.scripting.NashornScriptEngine.invokeFunction(NashornScriptEngine.java:190)
[21:00:52 WARN]:        at org.scriptcraftjs.bukkit.ScriptCraftPlugin.onEnable(ScriptCraftPlugin.java:38)
[21:00:52 WARN]:        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:254)
[21:00:52 WARN]:        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:339)
[21:00:52 WARN]:        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:403)
[21:00:52 WARN]:        at org.bukkit.craftbukkit.v1_13_R2.CraftServer.enablePlugin(CraftServer.java:434)
[21:00:52 WARN]:        at org.bukkit.craftbukkit.v1_13_R2.CraftServer.enablePlugins(CraftServer.java:348)
[21:00:52 WARN]:        at net.minecraft.server.v1_13_R2.MinecraftServer.l(MinecraftServer.java:584)
[21:00:52 WARN]:        at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:546)
[21:00:52 WARN]:        at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:424)
[21:00:52 WARN]:        at net.minecraft.server.v1_13_R2.DedicatedServer.init(DedicatedServer.java:294)
[21:00:52 WARN]:        at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:702)
[21:00:52 WARN]:        at java.lang.Thread.run(Unknown Source)
[21:00:52 ERROR]: [scriptcraft] Can't unambiguously select between fixed arity signatures [(org.bukkit.plugin.Plugin, java.util.function.Consumer, long), (org.bukkit.plugin.Plugin, java.lang.Runnable, long)] of the method org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftScheduler.runTaskLater for argument types [org.scriptcraftjs.bukkit.ScriptCraftPlugin, jdk.nashorn.internal.runtime.ScriptFunction, java.lang.Double]

[walterhiggins]

Whenever the following error occurs:

Can't unambiguously select between fixed arity signatures

It’s because of overloaded functions (specifically functions with the same number of params in their signature but with different param types). Rhino & Nashorn both let you explicitly specify which overload (signature) you want to use by specifying the function/param combo as a string property of the object. See https://github.com/walterhiggins/ScriptCraft/commit/f7601576bcc5b641b9833561c49fab9f2af4a333#diff-d09711779c520b5ceb965bc1a5ac5b4eL17

[jwulf]

There are two Java implementations for server.scheduler.runTaskLater, with different signatures - one that takes a java.lang.Runnable and another that takes a java.util.function.Consumer. The runtime selects the correct one based on the type of the arguments passed into the call.

The Javascript callback function is being passed to Java as a type jdk.nashorn.internal.runtime.ScriptFunction and needs to be cast into either a java.lang.Runnable or a java.util.function.Consumer. The problem is that Java can’t do that cast automatically - either because neither can be done, or because both could be done.

The patch @triyuga linked to explicitly specifies which implementation to use. That may work if the JVM can cast jdk.nashorn.internal.runtime.ScriptFunction -> java.lang.Runnable or -> java.util.function.Consumer.

Otherwise, I would try next explicitly constructing one of the accepted types from the callback. Maybe like this in src/js/main/lib/task-bukkit.js (from “Extending Java classes” here):

function bukkitSetTimeout( callback, delayInMillis ){
  var delay = Math.ceil( delayInMillis / 50 );
  var Run = Java.type("java.lang.Runnable");
  var MyRun = Java.extend(Run, {
    run: callback
  });
  var task = server.scheduler.runTaskLater( __plugin, new MyRun(), delay );
  return task;
}