ScriptFunction being passed to JSObject, expected ScriptObjectMirror

[Jesse Schulman]

Thanks for advising on how to best get undefined.

For the bug you opened I have worked around it for now by calling
ScriptUtil.wrap() when we get a ScriptFunction to turn it into a
ScriptObjectMirror.

I will track the issue at the URL you shared and remove the ScriptUtil.wrap
call once it's fixed.

Thanks again!
Jesse

On Mon, Aug 28, 2017 at 9:38 AM Sundararajan Athijegannathan <
sundararajan.athijegannathan at oracle.com> wrote:

> I think you can do something like this:
>
> import javax.script.*;
> import jdk.nashorn.api.scripting.JSObject;
>
> public class Main {
>   public static void main(String[] args) throws Exception {
>      ScriptEngineManager m = new ScriptEngineManager();
>      ScriptEngine e = m.getEngineByName("nashorn");
>      JSObject global = (JSObject) e.eval("this");
>      Object undefined = global.getMember("undefined");
>      System.out.println(undefined);
>   }
> }
>
> Thanks,
> -Sundar
>
>
> On 28/08/17, 10:03 PM, Jesse Schulman wrote:
>
> Awesome, thanks for the quick response!
>
> On a somewhat related note, what is the proper way of returning
> 'undefined' from a JSObject implementation?  I have seen it work various
> ways but when I have tested our application on the jdk9 beta releases I
> have had to take a different approach than Undefined.getUndefined() or
> ScriptRuntime.UNDEFINED since as you mention in that bug report the
> internal package cannot be accessed.
>
> Thanks again,
> Jesse
>
> On Sun, Aug 27, 2017 at 9:59 PM Sundararajan Athijegannathan <
> sundararajan.athijegannathan at oracle.com> wrote:
>
>> Hi,
>>
>> Thanks for the standalone test case! I reproduced the issue and filed a
>> bug -> https://bugs.openjdk.java.net/browse/JDK-8186807
>>
>> Thanks,
>> -Sundar
>>
>>
>> On 24/08/17, 11:11 PM, Jesse Schulman wrote:
>>
>> The type is ScriptFunction, I've created a simple reproducer that I've
>> pushed to https://github.com/jesseschulman/JSObject_gets_ScriptFunction
>> <https://github.com/jesseschulman/JSObject_gets_ScriptFunction.git>
>>
>> Thanks!
>> Jesse
>>
>> On Thu, Aug 24, 2017 at 1:05 AM Sundararajan Athijegannathan <
>> sundararajan.athijegannathan at oracle.com> wrote:
>>
>>> what is the type of args[0]? Can you print args[0].getClass() to check
>>> it?
>>>
>>> Thanks,
>>> -Sundar
>>>
>>>
>>> On 24/08/17, 9:14 AM, Jesse Schulman wrote:
>>>
>>> I did try running with -Dnashorn.apply2call=false when I saw the email
>>> for that fix but it did not resolve the issue.
>>>
>>> There is no exception thrown, but our JSObject.call method basically is
>>> no-op as a result of not getting a ScriptObjectMirror, it effectively looks
>>> like this:
>>>
>>>         @Override
>>>         public Object call(Object thiz, Object ... args) {
>>>             if (args.length < 2 || !(args[0] instanceof
>>> ScriptObjectMirror) || !((ScriptObjectMirror) args[0]).isFunction() ||
>>> !(args[1] instanceof Integer))
>>>                 return gScriptEnvironment.getUndefined();
>>>
>>>             // safely cast and call ScriptObjectMirror...
>>>        }
>>>
>>>
>>> I am continuing to work on reproducing it outside our application in a
>>> simple way.  In the mean time if there's any other information I can share
>>> besides a reproducing example, or suggestions on workarounds to try let me
>>> know.
>>>
>>> Thanks!
>>> Jesse
>>>
>>> On Wed, Aug 23, 2017 at 7:10 PM Sundararajan Athijegannathan <
>>> sundararajan.athijegannathan at oracle.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> Sorry for the delayed response. We need more info to debug this - in
>>>> particular, what is the exception (if any) thrown etc.
>>>>
>>>> I wonder if this is related to this recent apply-related fix ->
>>>>
>>>>
>>>> http://mail.openjdk.java.net/pipermail/nashorn-dev/2017-August/006998.html
>>>>
>>>> -Sundar
>>>>
>>>> On 22/08/17, 3:43 AM, Jesse Schulman wrote:
>>>> > This does not happen on the first run of the code but is consistently
>>>> > happening on the 17th run after a restart and from that point forward
>>>> is
>>>> > broken until we restart.
>>>> >
>>>> > Attached is a broken and working call stack.
>>>> >
>>>> > I have tried to replicate what we are doing in a basic java
>>>> reproducer but
>>>> > have not been able to do so, given that I can consistently reproduce
>>>> this
>>>> > locally I am happy to take any suggested steps to gather more
>>>> information
>>>> > or to workaround/resolve the issue.
>>>> >
>>>> > Environment:
>>>> > Java version 1.8.144
>>>> > Engine created with "--no-java", "-strict", "--no-syntax-extensions",
>>>> > "--language=es6", "--optimistic-types=true"  (also tried with
>>>> > optimistic-types=false)
>>>> > All evaluation done on the same engine via engine.eval(String,
>>>> Bindings)
>>>> > using a Bindings that was returned from engine.createBindings, each
>>>> of the
>>>> > "runs" described above took place in a different Bindings instance
>>>> >
>>>> > Thanks!
>>>> > Jesse
>>>>
>>>