kotlin / kotlin-script-examples

Examples of Kotlin Scripts and usages of the Kotlin Scripting API

Kotlin scripting examples

This repository contains example projects and individual scripts, as well as links to the external examples demonstrating Kotlin Scripting functionality and API usage.

If you know good examples of the Kotlin scripting API usage, not mentioned here, please submit an issue or a pull request with the link and short description.

Examples in this repository

The complete project could be compiled with Gradle, as well as imported e.g. in IntelliJ IDEA.

The individual example projects are mostly independent and could be copied and reused independently, but build files should be adapted accordingly, mostly to supply required Kotlin version properties and setup inter-project dependencies when needed

Script definitions with scripting hosts

• Simple script definition
• Script with dynamic dependencies from Maven
• Scripting Host with Kotlin Compiler Embeddable
• Simplified main-kts-like script implementation
• main-kts scripts examples
• using scripting via JSR 223 interface

External examples

• kotlin-asyncapi: Maven plugin and Spring Boot executable JAR scripting hosts

License

The Apache 2 license (given in full in LICENSE.txt applies to all code in this repository which is copyright by JetBrains.

kotlin-script-examples's Issues

Can't bind to engine

import org.junit.Test
import javax.script.ScriptEngineManager
import kotlin.test.assertEquals

class ScriptTest {

@Test
fun testSimpleEval() {
    val engine = ScriptEngineManager().getEngineByExtension("kts")!!
    val res = engine.eval("2+4")
    assertEquals(6,res)
}

@Test
fun testSimpleBinding() {
    val engine = ScriptEngineManager().getEngineByExtension("kts")!!
    engine.put("hello","world")
    val res = engine.eval("hello")
    assertEquals("world",res)
}

}

I've got

javax.script.ScriptException: Unresolved reference: hello
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.compileAndEval(KotlinJsr223JvmScriptEngineBase.kt:65)
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.eval(KotlinJsr223JvmScriptEngineBase.kt:31)

No documentation provided for Repository interface

Hello,

I was not able to find any documentation wrt the Repository interface.

My current problem is that I can't find a way to provide credentials to a private Nexus registry

I have created a topic in Kotlin lang Discourse

Once I discover how to provide credentials to @RepositoryI'll be able to submit a PR with an example.

If anybody can help with that, please let me know!

JSR223 tests fail with NPE at getEngine call

I was trying these examples out because of the discussion here: https://discuss.kotlinlang.org/t/run-user-code-in-the-server/18976?u=wasabi375

I noticed that I can't run the JSR examples. They fail with a NPE during ScriptEngineManager().getEngineByExtension("main.kts")!!

I'm guessing that I am missing something during the build setup. Do I have to install anything in addition? I didn't see anything in the readme.

KotlinJsr223DefaultScriptEngineFactory not needed anymore?

Sorry for this question-like type of issue, but when reading though

kotlin-script-examples/jvm/jsr223/jsr223-simple/src/main/kotlin/org/jetbrains/kotlin/script/examples/jvm/jsr223/simple/repl.kt

Line 11 in d48abed

val engine = ScriptEngineManager().getEngineByExtension("kts")!!

I was wondering why there is no META-INF/services/javax.script.ScriptEngineFactory file anymore which contains the string kotlin.script.experimental.jsr223.KotlinJsr223DefaultScriptEngineFactory. Is this not needed anymore? Since when? Any official docs on that?

Using ScriptEngineManager to eval a class script file returns null

Kotlin version 1.8.20

Simple class defined in a file called simple.kts
class Test {
val x = 5
}

Testing the Script Engine Manager using the following:
@test
fun testClassCompile() {
val scriptReader = this::class.java.classLoader.getResource("simple.kts").openStream().reader()
val engine = ScriptEngineManager().getEngineByExtension("kts")
try {
val result = engine.eval(scriptReader)
assertNotNull(result)
}catch (se: ScriptException) {
fail()
}
}

If I am not mistaken this test should be returning an Object of type Class and not null. Please correct me if I am incorrect or have misunderstood how to get the Class object back.

Consider editing repository setings to remove "Packages" section

"Packages No packages published" is displayed right now, fortunately this pointless section can be removed.

Edit repo page config to remove it (cog next to the description).

I am not making a PR as it is defined in proprietary github settings, not in a git repository - and I have no rights to modify repo settings.

Maybe also releases should be removed

Unable to find extension point configuration extensions/compiler.xml

javax.script.ScriptException: ERROR Unable to initialize repl compiler:
DEBUG Using JDK home inferred from java.home: D:\2_My_Work_Application\graalvm-ce-java17-22.3.0
DEBUG Using JVM IR backend
ERROR Unable to find extension point configuration extensions/compiler.xml (cp:
null): java.lang.IllegalStateException: Unable to find extension point configuration extensions/compiler.xml (cp:
null): java.lang.IllegalStateException: Unable to initialize repl compiler:
DEBUG Using JDK home inferred from java.home: D:\2_My_Work_Application\graalvm-ce-java17-22.3.0
DEBUG Using JVM IR backend
ERROR Unable to find extension point configuration extensions/compiler.xml (cp:
null): java.lang.IllegalStateException: Unable to find extension point configuration extensions/compiler.xml (cp:
null)
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.asJsr223EvalResult(KotlinJsr223JvmScriptEngineBase.kt:104)
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.compileAndEval(KotlinJsr223JvmScriptEngineBase.kt:63)
at kotlin.script.experimental.jvmhost.jsr223.KotlinJsr223ScriptEngineImpl.compileAndEval(KotlinJsr223ScriptEngineImpl.kt:95)
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.eval(KotlinJsr223JvmScriptEngineBase.kt:31)
at java.scripting/javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:262)
at cn.hutool.script.FullSupportScriptEngine.eval(FullSupportScriptEngine.java:101)
at com.jnvago.jniot.terminal.resolver.subscribe.second.ScriptCache.set(ScriptCache.kt:77)
... 34 common frames omitted

No Simple Example Exists

All these examples are too complicated, brittle, and fragile. Can someone please give the most simple working example possible with only two files

1. main.kt
2. script.kts

When I try to run the simple example I get

: wrong number of arguments: 0 expected: 1: java.lang.IllegalArgumentException: wrong number of arguments: 0 expected: 1

Some main.kts examples

If you know good examples of the Kotlin scripting API usage, not mentioned here, please submit an issue or a pull request with the link and short description.

Same examples

Rsocket proxy https://github.com/yschimke/okurl-scripts/blob/master/commands/rsocketTcpProxy.main.kts

Fetch mp3s and download example https://github.com/yschimke/okurl-scripts/blob/master/commands/showList.main.kts

Some requiring external configuration (a token stored by https://github.com/yschimke/okurl/)

A github graphql example https://github.com/yschimke/okurl-scripts/blob/master/commands/github-pull-requests.main.kts
gmail https://github.com/yschimke/okurl-scripts/blob/master/commands/gmail-inbox.main.kts

embeddableTest.kt in jvm-embeddabble-host fails.

When attempting to run the tests in jvm-embeddabble-host the following exception is thrown.

kotlin.script.experimental.jvm.util.ClasspathExtractionException: Unable to get script compilation classpath from context, please specify explicit classpath via "kotlin.script.classpath" property

	at kotlin.script.experimental.jvm.util.JvmClasspathUtilKt.scriptCompilationClasspathFromContext(jvmClasspathUtil.kt:345)
	at kotlin.script.experimental.jvm.JvmScriptCompilationKt.dependenciesFromClassloader(jvmScriptCompilation.kt:57)
	at kotlin.script.experimental.jvm.JvmScriptCompilationKt.dependenciesFromClassloader$default(jvmScriptCompilation.kt:50)
	at kotlin.script.experimental.jvm.JvmScriptCompilationKt.dependenciesFromCurrentContext(jvmScriptCompilation.kt:47)
	at kotlin.script.experimental.jvm.JvmScriptCompilationKt.dependenciesFromCurrentContext$default(jvmScriptCompilation.kt:42)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.host.HostKt$evalFile$compilationConfiguration$1$1.invoke(host.kt:21)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.host.HostKt$evalFile$compilationConfiguration$1$1.invoke(host.kt:20)
	at kotlin.script.experimental.util.PropertiesCollection$Builder.invoke(propertiesCollection.kt:282)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.host.HostKt$evalFile$compilationConfiguration$1.invoke(host.kt:20)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.host.HostKt$evalFile$compilationConfiguration$1.invoke(host.kt:19)
	at kotlin.script.experimental.host.ConfigurationFromTemplateKt$constructCompilationConfiguration$1.invoke(configurationFromTemplate.kt:113)
	at kotlin.script.experimental.host.ConfigurationFromTemplateKt$constructCompilationConfiguration$1.invoke(configurationFromTemplate.kt:109)
	at kotlin.script.experimental.api.ScriptCompilationConfiguration.<init>(scriptCompilation.kt:22)
	at kotlin.script.experimental.api.ScriptCompilationConfiguration.<init>(scriptCompilation.kt:27)
	at kotlin.script.experimental.host.ConfigurationFromTemplateKt.constructCompilationConfiguration(configurationFromTemplate.kt:109)
	at kotlin.script.experimental.host.ConfigurationFromTemplateKt.createCompilationConfigurationFromTemplate(configurationFromTemplate.kt:67)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.host.HostKt.evalFile(host.kt:72)
	at org.jetbrains.kotlin.script.examples.jvm.embeddable.test.SimpleTest.testSimple(embeddableTest.kt:20)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

request: sample to get return value of eval

can you add sample to get return value of eval() ?

something like this:

val result : ResultWithDiagnostics<EvaluationResult> = eval(...)

result.castOrError<ResultWithDiagnostics.Success<EvaluationResult>> {
    "script evaluation failed. $it"
}.value.returnValue.castOrError<ResultValue.Value> {
    "script evaluation result is $it"
}.value.castOrError<AppConfig> { // your expected class for value
    "script returns value, but it's not AppConfig. ${it?.javaClass?.simpleName}"
}.let { config = it }

inline fun <reified T:Any> Any?.castOrError(noinline messageCreator:(Any?)->String) =
    (this as? T) ?: error(messageCreator(this))

Show how to configure auto-completion in IntelliJ

Could you please extend the examples to also make auto-completion, e.g. in hello-kotlinx-html.scriptwithdeps.kts, work in IntelliJ?

For example, if I'm extending ScriptWithMavenDeps with a dummy property like

abstract class ScriptWithMavenDeps {
    val dummy: String = "oink"
}

what does it take to offer dummy when typing this. in hello-kotlinx-html.scriptwithdeps.kts?

Caused by: javax.script.ScriptException: Unresolved reference: Import

Hey, what am I doing wrong, if I cannot import in my kts files?

Some pseudocode:

otherfolder/otherfile.kts

fun otherFn() {
  // ...
}

main.kts

@file:Import("otherfolder/otherfile.kts")

fun main() {
  otherFn()
}

I am getting:

Caused by: javax.script.ScriptException: Unresolved reference: Import
Unresolved reference: Import
Unresolved reference: otherFn

This is how I load them in my kotlin/spring app:

        val scriptEngine = ScriptEngineManager().getEngineByExtension("kts")
        val fileReader = FileReader(Paths.get("src/main/resources/main.kts").toFile())
        scriptEngine.eval(fileReader)
        return scriptEngine as Invocable

    kotlin("jvm") version "1.4.21"
    // ...
    implementation( "org.jetbrains.kotlin:kotlin-script-runtime")
    implementation( "org.jetbrains.kotlin:kotlin-script-util")
    implementation( "org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable")
    implementation( "org.jetbrains.kotlin:kotlin-scripting-jvm-host")
    implementation( "org.jetbrains.kotlin:kotlin-scripting-jsr223")