Dokka: KotlinNullPointerException when running gradle task in kotlin2js project

[motorro]

Hi!

I'm having problem running dokka task in a kotlin2js project.
Got kotlin.KotlinNullPointerException (no error message) here after:

18:12:56.616 [DEBUG] [org.gradle.api.Task] Dokka found AbstractKotlinCompile task: task ':compileKotlin2Js'

Stack trace:

kotlin.KotlinNullPointerException
  at org.jetbrains.dokka.ReflectDsl$CallOrPropAccess.v(ReflectDsl.kt:30)
  at org.jetbrains.dokka.ReflectDsl$CallOrPropAccess.get(ReflectDsl.kt:18)
  at org.jetbrains.dokka.gradle.DokkaTask.extractClasspathAndSourceRootsFromKotlinTasks(main.kt:216)
  at org.jetbrains.dokka.gradle.DokkaTask.access$extractClasspathAndSourceRootsFromKotlinTasks(main.kt:54)
  at org.jetbrains.dokka.gradle.DokkaTask$kotlinCompileBasedClasspathAndSourceRoots$2.invoke(main.kt:116)
  at org.jetbrains.dokka.gradle.DokkaTask$kotlinCompileBasedClasspathAndSourceRoots$2.invoke(main.kt:54)
  at kotlin.SynchronizedLazyImpl.getValue(Lazy.kt:130)
  at org.jetbrains.dokka.gradle.DokkaTask.getKotlinCompileBasedClasspathAndSourceRoots$gradle_plugin_main(main.kt)
  at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
  at org.gradle.api.internal.project.taskfactory.TaskPropertyInfo$4.create(TaskPropertyInfo.java:99)
  at org.gradle.util.SingleMessageLogger.whileDisabled(SingleMessageLogger.java:217)
  at org.gradle.api.internal.project.taskfactory.TaskPropertyInfo.getValue(TaskPropertyInfo.java:97)
  at org.gradle.api.internal.project.taskfactory.TaskClassValidator.validate(TaskClassValidator.java:78)
  at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:41)
  at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:88)
  at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:52)
  at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
  at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
  at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
  at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
  at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:242)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:317)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:309)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:185)
  at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:95)
  at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:235)
  at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:224)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:121)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:77)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:102)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:96)
  at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:612)
  at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:567)
  at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:96)
  at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
  at org.gradle.internal.concurrent.StoppableExecutorImpl$1.run(StoppableExecutorImpl.java:46)
  at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)

Build file (based on this example) :

apply plugin: 'kotlin2js'
apply plugin: 'org.jetbrains.dokka'
apply plugin: 'com.moowork.node'

buildscript {
    ext.kotlin_version = '1.1.4-3'
    repositories {
        jcenter()
        mavenCentral()
        maven { url "https://plugins.gradle.org/m2/" }
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.moowork.gradle:gradle-node-plugin:1.2.0'
        classpath 'org.jetbrains.dokka:dokka-gradle-plugin:0.9.15'
    }
}

repositories {
    mavenCentral()
    jcenter()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-js:$kotlin_version"
    testCompile "org.jetbrains.kotlin:kotlin-test-js:$kotlin_version"
}

[compileKotlin2Js, compileTestKotlin2Js]*.configure {
    kotlinOptions.metaInfo = true
    kotlinOptions.sourceMap = true
    kotlinOptions.moduleKind = "commonjs"
}

task populateNodeModules(type: Copy, dependsOn: compileKotlin2Js) {
   from compileKotlin2Js.destinationDir

   configurations.testCompile.each {
       from zipTree(it.absolutePath).matching { include '*.js' }
   }

   into "${buildDir}/node_modules"
}

node { 
  download = true
}

dokka {
    outputFormat = 'html'
    outputDirectory = "${projectDir}/doc"
}

task installMocha(type: NpmTask) {
    args = ['install', 'mocha']
}

task runMocha(type: NodeTask, dependsOn: [compileTestKotlin2Js, populateNodeModules, installMocha]) {
    script = file('node_modules/mocha/bin/mocha')
    args = [compileTestKotlin2Js.outputFile]
}

test.dependsOn runMocha

Gradle version: 4.0

[napperley]

As a temporary workaround downgrading Dokka to version 0.9.14 resolves the issue.

[Flamenco]

Any other thoughts on when this will be resolved, or other workarounds? I am trying to use this on a multi-platform build with the 'suppress = true' option, so downgrading is not an option for me. Will the code work by just ignoring the exception and adding user supplied sources instead?

[rjaros]

My workaround is to change kotlin-js plugin to kotlin-jvm plugin for "dokka" task only:

if (!project.gradle.startParameter.taskNames.contains("dokka")) {
    apply plugin: 'kotlin2js'
} else {
    apply plugin: 'kotlin'
}

...

dependencies {
    if (!project.gradle.startParameter.taskNames.contains("dokka")) {
        compile "org.jetbrains.kotlin:kotlin-stdlib-js:$kotlin_version"
    } else {
        compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    }
}

...

if (!project.gradle.startParameter.taskNames.contains("dokka")) {
    compileKotlin2Js {
        kotlinOptions.metaInfo = true
        kotlinOptions.moduleKind = 'commonjs'
    }
}

[SalomonBrys]

This is still not resolved in 0.9.16.

[Shengaero]

0.9.17 is still having this issue, is there any plans to fix it?

[semoro]

This issue much deeper then just NPE, it caused by Dokka not supporting JS platform right now, it will be fixed as support for JS will be available

[rjaros]

Any roadmap for JS support?

[semoro]

It will be added as part of multiplatform projects support

[KrystianUjma]

merged to branch. Will be released in 0.9.19.