JS Compiler Bug in Delegated Suspend Functions

[FLUXparticle]

There seems to be a bug in the kotlin2js compiler. When a suspend function is part of a delegate, the suspend function is called without continuation object. Here is a simple example: (tested with version 1.2.41)

interface SuspendInterface {

    suspend fun hello()

}

object SuspendObject : SuspendInterface {

    override suspend fun hello() {
        delay(1000)
        println("Hello from Kotlin Coroutines!")
    }

}

class SuspendDelegate(suspendInterface: SuspendInterface) :
        SuspendInterface by suspendInterface

fun main(args: Array<String>) {
    println("Hello World!")
    launch {
        SuspendObject.hello()
        SuspendDelegate(SuspendObject).hello()
    }
}

The first call to hello() works as expected. The second one throws an exception:

TypeError: Cannot read property 'context' of undefined
    at Coroutine$hello.CoroutineImpl (kotlin.js:30956)
    at new Coroutine$hello (suspend.js:35)
    at SuspendObject.hello (suspend.js:28)
    at SuspendDelegate.hello (suspend.js:91)
    at Coroutine$main$lambda.doResume (suspend.js:131)
    at Coroutine$main$lambda.CoroutineImpl.doResumeWrapper_0 (kotlin.js:30976)
    at Coroutine$main$lambda.CoroutineImpl.resume_11rb$ (kotlin.js:30965)
    at Coroutine$hello.CoroutineImpl.doResumeWrapper_0 (kotlin.js:30978)
    at Coroutine$hello.CoroutineImpl.resume_11rb$ (kotlin.js:30965)
    at resumeMode (kotlinx-coroutines-core.js:602)

[qwwdfsad]

Thank you for the report.
This is a known bug KT-23094 in kotlin2js compiler (not in kotlinx.coroutines).

As a workaround you can use handwritten delegation like we do https://github.com/Kotlin/kotlinx.coroutines/blob/develop/common/kotlinx-coroutines-core-common/src/main/kotlin/kotlinx/coroutines/experimental/channels/ChannelCoroutine.kt#L31

[systemkern]

I think the link should be to this file
https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-core/common/src/channels/ChannelCoroutine.kt