define a default js engine

[davidcoutadeur]

Currently, there are multiple ways to use javascript in dataset/pivot transformation/conditions.

In next version 2.2, we'll have the new graalvm engine.

See also:

• Java 11+ javascript engine compatibility #133
• javascript graaljs support and rhino update #208

Multiple issues here:

1. it's not completely clear to me what js engine is used by default in LSC now (for example if no tag js: is present). I suppose it is graalvm. We should document this, and especially in https://lsc-project.org/documentation/latest/scripting.html

For example, in lsc.xml, we sometimes have dataset like these:

        <dataset>
                <name>favouriteDrink</name>
                <forceValues>
                  <string><![CDATA[js:
                    var value = srcBean.getDatasetFirstValueById("favouriteDrink");
                    value.replace('-src', '-dst');
                ]]></string>
                </forceValues>
        </dataset>

But even if js: is specified here, the graaljs engine seems used for evaluation (as shown in the logs below)

We should clarify in documentation:

• what engine is really used,
• if it is launched in a compatibility mode or other specific behaviors...
• describe the migration steps if the users of version 2.1 should migrate the script engine of their configuration to use a specific engine in 2.2.
• describe the limitation of the js engine they are using

2. it seems that the engine behind js: is not supporting the java object anymore in java 17. This leads to errors like this one:

17:15:07.338 [ldap2ldapSamePivotConversionTestTask-38] DEBUG org.lsc.utils.JScriptEvaluator - javax.script.ScriptException: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
javax.script.ScriptException: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
        at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.toScriptException(GraalJSScriptEngine.java:503)
        at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:480)
        at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:446)
        at java.scripting/javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:231)
        at org.lsc.utils.JScriptEvaluator.instanceEval(JScriptEvaluator.java:310)
        at org.lsc.utils.JScriptEvaluator.evalToString(JScriptEvaluator.java:104)
        at org.lsc.utils.ScriptingEvaluator.evalToString(ScriptingEvaluator.java:152)
        at org.lsc.AbstractSynchronize.transform(AbstractSynchronize.java:449)
        at org.lsc.AbstractSynchronize.getBean(AbstractSynchronize.java:430)
        at org.lsc.runnable.SynchronizeEntryRunner.run(SynchronizeEntryRunner.java:87)
        at org.lsc.runnable.SynchronizeEntryRunner.run(SynchronizeEntryRunner.java:45)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
        at <js>.:program(<eval>:1)
        at org.graalvm.sdk/org.graalvm.polyglot.Context.eval(Context.java:399)
        at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:478)
        ... 12 common frames omitted
17:15:07.339 [ldap2ldapSamePivotConversionTestTask-38] ERROR org.lsc.AbstractSynchronize - Error while synchronizing ID {favouritedrink=0003-src}: org.lsc.exception.LscServiceException: javax.script.ScriptException: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
17:15:07.339 [ldap2ldapSamePivotConversionTestTask-36] ERROR org.lsc.utils.JScriptEvaluator - Fail to compute expression: 
                        value.replace('-src', '-dst');
                 on unknown id !

Removing js: before each script in the lsc.xml used for test solves the issue here. Using explicitely gj: also solves the issue.

I'll push a PR for fixing the tests.

@artlog: as you have worked on graaljs engine, if you have some infos, don't hesite to share here.

[vikinghawk]

@davidcoutadeur does the team have an idea when 2.2 would be released?

[davidcoutadeur]

@davidcoutadeur does the team have an idea when 2.2 would be released?

The team is working on the last issues. As this is a community project, we can't promise to release at a well-defined date. Though, there are not much issues for finishing the release (66% of issues closed)