Websocket with Kotlin suspend function throws NullPointerException on DelegatingCoroutineContext

[lpicanco]

Expected Behavior

This code should work:

@ServerWebSocket("/")
class WebsocketController {
    @OnMessage
    suspend fun messageHandler(message: String, session: WebSocketSession) {
        delay(500)
    }
}

Actual Behaviour

NullPointerException error:

[default-nioEventLoopGroup-1-2] ERROR i.m.h.s.n.w.NettyServerWebSocketHandler - Unexpected Exception in WebSocket [com.example.WebsocketController@3cd3e42e]: null
java.lang.NullPointerException: null
        at io.micronaut.http.bind.binders.DelegatingCoroutineContext.get(ContinuationArgumentBinder.kt:105)
        at kotlinx.coroutines.CancellableContinuationImpl.installParentHandle(CancellableContinuationImpl.kt:306)
        at kotlinx.coroutines.CancellableContinuationImpl.initCancellability(CancellableContinuationImpl.kt:98)
        at kotlinx.coroutines.DelayKt.delay(Delay.kt:166)
        at com.example.WebsocketController.messageHandler(WebsocketController.kt:12)
        at com.example.$WebsocketController$Definition$Exec.dispatch(Unknown Source)
        at io.micronaut.context.AbstractExecutableMethodsDefinition$DispatchedExecutableMethod.invoke(AbstractExecutableMethodsDefinition.java:378)
        at io.micronaut.core.bind.DefaultExecutableBinder$1.invoke(DefaultExecutableBinder.java:109)
        at io.micronaut.http.server.netty.websocket.NettyServerWebSocketHandler.lambda$invokeExecutable0$6(NettyServerWebSocketHandler.java:349)
        at io.micronaut.http.context.ServerRequestContext.with(ServerRequestContext.java:103)
        at io.micronaut.http.server.netty.websocket.NettyServerWebSocketHandler.invokeExecutable0(NettyServerWebSocketHandler.java:348)
        at io.micronaut.http.server.netty.websocket.NettyServerWebSocketHandler.lambda$invokeExecutable$5(NettyServerWebSocketHandler.java:330)
        at reactor.core.publisher.FluxDeferContextual.subscribe(FluxDeferContextual.java:49)
        at reactor.core.publisher.Flux.subscribe(Flux.java:8660)
        at io.micronaut.http.server.netty.websocket.NettyServerWebSocketHandler.lambda$instrumentPublisher$3(NettyServerWebSocketHandler.java:283)
        at io.micronaut.http.context.ServerRequestContext.with(ServerRequestContext.java:68)
        at io.micronaut.http.server.netty.websocket.NettyServerWebSocketHandler.lambda$instrumentPublisher$4(NettyServerWebSocketHandler.java:282)
        at reactor.core.publisher.FluxSource.subscribe(FluxSource.java:67)
        at reactor.core.publisher.InternalFluxOperator.subscribe(InternalFluxOperator.java:62)
        at reactor.core.publisher.FluxSubscribeOn$SubscribeOnSubscriber.run(FluxSubscribeOn.java:194)
        at io.micronaut.reactive.reactor.instrument.ReactorInstrumentation.lambda$init$0(ReactorInstrumentation.java:62)
        at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:84)
        at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:37)
        at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:96)
        at io.netty.util.concurrent.PromiseTask.run(PromiseTask.java:106)
        at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174)
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167)
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:566)
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:1589)

Steps To Reproduce

1. Run ./gradlew run
2. On another terminal run: 2.1. npm install artillery 2.2. node_modules/.bin/artillery run loadtest.yml
3. See error: java.lang.NullPointerException: null at io.micronaut.http.bind.binders.DelegatingCoroutineContext.get(ContinuationArgumentBinder.kt:105)

Environment Information

• OS: Macos Venture 13.1
• JDK: 11.0.14-ms

Example Application

https://github.com/lpicanco/micronaut-wsocket-coroutine-error

Version

3.8.2

[lpicanco]

It seems to be related to #6582

[stralytic]

I've also got this issue. My digging points to ContinuationArgumentBinder.bind creating a brand new CustomContinuation when one already exists in the source HttpRequest object. This brand new CustomContinuation never has its delegatingCoroutineContext set, but the one in the HttpRequest does have one set.

[yawkat]

is this still an issue in 4? i cant reproduce yet because of old node version