Precompiling js script files fails from docker container

[gkontos]

When running the container 'outofcoffee/imposter-all:3.36.0' with a script, the following error is encountered:

20:06:34 DEBUG i.g.i.s.n.s.NashornScriptServiceImpl - Precompiling script: /opt/imposter/config/scripts/myscript.js
Exception in thread "DefaultDispatcher-worker-1" com.google.common.util.concurrent.ExecutionError: java.lang.IncompatibleClassChangeError: Found interface org.objectweb.asm.FieldVisitor, but class was expected
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2053)
	at com.google.common.cache.LocalCache.get(LocalCache.java:3966)
	at com.google.common.cache.LocalCache$LocalManualCache.get(LocalCache.java:4863)
	at io.gatehill.imposter.scripting.nashorn.service.NashornScriptServiceImpl.getCompiledScript(NashornScriptServiceImpl.kt:171)
	at io.gatehill.imposter.scripting.nashorn.service.NashornScriptServiceImpl.initScript(NashornScriptServiceImpl.kt:105)
	at io.gatehill.imposter.scripting.common.service.DelegatingJsScriptServiceImpl.initScript(DelegatingJsScriptServiceImpl.kt:86)
	at io.gatehill.imposter.service.script.ScriptedResponseServiceImpl.initScriptFilesAndSteps(ScriptedResponseServiceImpl.kt:149)
	at io.gatehill.imposter.service.script.ScriptedResponseServiceImpl.initScripts(ScriptedResponseServiceImpl.kt:125)
	at io.gatehill.imposter.service.script.ScriptedResponseServiceImpl.afterRoutesConfigured(ScriptedResponseServiceImpl.kt:110)
	at io.gatehill.imposter.Imposter$configureRoutes$5.invoke(Imposter.kt:228)
	at io.gatehill.imposter.Imposter$configureRoutes$5.invoke(Imposter.kt:227)
	at io.gatehill.imposter.lifecycle.LifecycleHooks.forEach(LifecycleHooks.kt:77)
	at io.gatehill.imposter.Imposter.configureRoutes(Imposter.kt:227)
	at io.gatehill.imposter.Imposter.access$configureRoutes(Imposter.kt:88)
	at io.gatehill.imposter.Imposter$start$1.invokeSuspend(Imposter.kt:135)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:108)
	at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:584)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:793)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:697)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:684)
	Suppressed: kotlinx.coroutines.internal.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@2c1cd0b0, Dispatchers.Default]
Caused by: java.lang.IncompatibleClassChangeError: Found interface org.objectweb.asm.FieldVisitor, but class was expected
	at org.openjdk.nashorn.internal.codegen.ClassEmitter.field(ClassEmitter.java:606)
	at org.openjdk.nashorn.internal.codegen.ClassEmitter.field(ClassEmitter.java:619)
	at org.openjdk.nashorn.internal.codegen.ClassEmitter.defineCommonStatics(ClassEmitter.java:270)
	at org.openjdk.nashorn.internal.codegen.ClassEmitter.<init>(ClassEmitter.java:210)
	at org.openjdk.nashorn.internal.codegen.Compiler.createCompileUnit(Compiler.java:766)
	at org.openjdk.nashorn.internal.codegen.Compiler.createCompileUnit(Compiler.java:774)
	at org.openjdk.nashorn.internal.codegen.Compiler.addCompileUnit(Compiler.java:759)
	at org.openjdk.nashorn.internal.codegen.CompilationPhase$SplittingPhase.transform(CompilationPhase.java:117)
	at org.openjdk.nashorn.internal.codegen.CompilationPhase.apply(CompilationPhase.java:614)
	at org.openjdk.nashorn.internal.codegen.Compiler.compile(Compiler.java:641)
	at org.openjdk.nashorn.internal.runtime.Context.compile(Context.java:1531)
	at org.openjdk.nashorn.internal.runtime.Context.compileScript(Context.java:785)
	at org.openjdk.nashorn.api.scripting.NashornScriptEngine.asCompiledScript(NashornScriptEngine.java:486)
	at org.openjdk.nashorn.api.scripting.NashornScriptEngine.compile(NashornScriptEngine.java:178)
	at io.gatehill.imposter.scripting.nashorn.service.NashornScriptServiceImpl.getCompiledScript$lambda$3(NashornScriptServiceImpl.kt:180)
	at com.google.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4868)
	at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3533)
	at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2282)
	at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2159)
	at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2049)
	... 20 more

The script in question was simplified to

var requestStore = stores.open('myRequest');

respond()
    .usingDefaultBehaviour()

This error does not occur when running the same version of imposter through the CLI or Jar files when running with openJDK 19 or jdk-22.

[rnestler]

I hit the same issue. It does work with the outofcoffee/imposter image, but https://docs.imposter.sh/scripting_modern_js/ recommended to use the gral-js plugin which I hoped would be included in the outofcoffee/imposter-all image.

[gkontos]

Ah! We didn't try the gral-js plugin, just the default js. We were using imposter-all for the faker plugin.

[outofcoffee]

Hi @gkontos and @rnestler - thank you for raising this and investigating.

This is caused by a clash between some of the plugins included in the all distro. Whilst we work on fixing that, there's an interim solution where the all distro now includes the js-graal plugin as suggested by @rnestler.

This is released in v3.36.1.

It looks like the work-around you used (specifying the IMPOSTER_JS_PLUGIN=js-graal environment variable) avoids this issue in v3.36.1.

[outofcoffee]

The underlying issue with the plugin conflict in the all distro should be fixed in v3.36.2.

Please let me know if this resolves the issue.

[rnestler]

v3.36.2 fixes the issue for me. I was wondering why graal-js isn't the default though. It was very surprising to me, that the JS scripting didn't support "modern" features by default.

[gkontos]

The update resolves the issue for me too. Thanks!