[bug] javascript UDFs receive json arguments as empty objects

[dark-ether]

Describe the Bug

if you have a js UDF which takes a json it will receive a empty object instead of whatever argument you give it

To Reproduce

1. create a token name lib:test and set allow uri acess
2. create test macro with

function test(arrayOfObject){	
MapTool.chat.broadcast(JSON.stringify(arrayOfObject));
return arrayOfObject;
}

MTScript.registerMacro("test",test);

3. create define test macro with [r:js.evalURI("test","lib://test/macro/test")] command
4. create use test with

[h:objectWithArray = json.append("[]","array1","dsdas,dsd","array2",4)]
[h:js.test(objectWithArray)]

5. see that ouput to chat is empty object instead of array with 4 values

Expected Behaviour

arguments that the js UDF receives should be the ones i use, and not always an empty object

Screenshots

No response

MapTool Info

1.11.0

Desktop

arch linux

Additional Context

No response

[perkinslr]

The object passed in to the js UDF is a com.google.gson.JsonArray, which is a mostly-opaque type to javascript. Calling JSON.stringify on it returns the "own properties" of the argument, which is empty, hence the empty object as the output.

Currently, the only exposed interface for com.google.gson.* is string conversion, with complex types then requiring deserialization.

function test(arrayOfObject){	
  let myArray = JSON.parse(new String(arrayOfObject))
  MapTool.chat.broadcast(JSON.stringify(myArray));
  return myArray;
}

MTScript.registerMacro("test",test);

Until a week or so ago, I was under the impression that MapTool kept json data internally as strings, so I did not handle gson data coming in to js UDFs. I will see if I can adjust the GraalVM-js security policy to allow full access to gson data. Or failing that, handle converting gson data to graalvm-js data automatically.

[cwisniew]

I think converting between gson and graalvm-js is best way to go, I would hate to get into the position where a upgrade to gson (or change to some other library) would break people's macros.

[Phergus]

Tested using test case described above. Working as expected.