Kotlin scripting support fails with "wrong number of arguments" whenever I try to run any script

Question

I'm trying to run a very basic script with org.jetbrains.kotlin:kotlin-scripting-jvm, but I get two errors, when I should get none. This is my script:

1

I expect to get back a ResultWithDiagnostics.Success with a resultValue of 1 but instead I get a Failure, with these reports:

• The expression is unused
• wrong number of arguments

Even if I fix the warning by modifying my script to

class Foo(val foo: String = "foo")

Foo()

I still get the wrong number of arguments error. I checked the source and it seems that in

BasicJvmScriptEvaluator:95
        return try {
            ctor.newInstance(*args.toArray()) <-- here
        } finally {
            Thread.currentThread().contextClassLoader = saveClassLoader
        } 

args is empty. What am I doing wrong? This is how I try to run the script:

private fun evalFile(scriptFile: File): ResultWithDiagnostics<EvaluationResult> {
    val compilationConfiguration = createJvmCompilationConfigurationFromTemplate<TestScript> {
        jvm {
            dependenciesFromCurrentContext(wholeClasspath = true)
        }
    }

    return BasicJvmScriptingHost().eval(scriptFile.toScriptSource(), compilationConfiguration, null)
}

and this is the stack trace for this wrong number of arguments error I get:

java.lang.IllegalArgumentException: wrong number of arguments
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at kotlin.script.experimental.jvm.BasicJvmScriptEvaluator.evalWithConfigAndOtherScriptsResults(BasicJvmScriptEvaluator.kt:95)
    at kotlin.script.experimental.jvm.BasicJvmScriptEvaluator.invoke$suspendImpl(BasicJvmScriptEvaluator.kt:40)
    at kotlin.script.experimental.jvm.BasicJvmScriptEvaluator.invoke(BasicJvmScriptEvaluator.kt)
    at kotlin.script.experimental.host.BasicScriptingHost$eval$1.invokeSuspend(BasicScriptingHost.kt:47)
    at kotlin.script.experimental.host.BasicScriptingHost$eval$1.invoke(BasicScriptingHost.kt)
    at kotlin.script.experimental.host.BasicScriptingHost$runInCoroutineContext$1.invokeSuspend(BasicScriptingHost.kt:35)
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
    at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:238)
    at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.kt:116)
    at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:80)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:54)
    at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
    at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:36)
    at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
    at kotlin.script.experimental.host.BasicScriptingHost.runInCoroutineContext(BasicScriptingHost.kt:35)
    at kotlin.script.experimental.host.BasicScriptingHost.eval(BasicScriptingHost.kt:45)

Answer 1

This isn't fix, just workaround.

You can pass the source code to Kotlin Compiler by the different ways:

1. From FileScriptSource - when you pass list of files in the configuration
2. From the list of source code content in memory - e.g. each file should be read and content should be placed inside StringScriptSource
3. From the single memory script, which is created just with all input source files concatenation.

As I found in my experiments:

• If you have mockk+kotest jars in the same classpath, option 1 doesn't work. In that case I'd like to assume for you to make one change:

// this doesn't work - scriptFile.toScriptSource()
scriptFile.readText().toScriptSource() // ok - we read source from memory, not from file

• If you have huge service with a lot of Spring jars, all options above work. It means that you couldn't test your compilation in the unit tests, however your service will work!
• If you want to do compilation from Gradle Plugin, you can catch another kind of issue - class conflict with coroutines library, so all options above don't work.

Finally, I changed the following in my code:

1. On input I always have a lot of kt/kts files.
2. I have three compilation options (described above). So my code executes createJvmCompilationConfigurationFromTemplate with the different logic, according on my compilation mode (it is just enum).
3. For unit tests I have to use option 3 only.
4. For service I use the first option as it is the fastest one
5. For gradle plugin classpath I start separate instance of java (with fresh classpath) which executes the input kts files.