Resteasy-Reactive: ExceptionMapper is not called when using Kotlin Flow

[mschorsch]

Describe the bug

If an exception is thrown within the Flow, the ExceptionMapper is not called and the request does not end.

Expected behavior

No response

Actual behavior

No response

How to Reproduce?

import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.flow
import org.jboss.resteasy.reactive.NoCache
import org.jboss.resteasy.reactive.common.util.RestMediaType
import javax.enterprise.context.ApplicationScoped
import javax.ws.rs.GET
import javax.ws.rs.Path
import javax.ws.rs.Produces
import org.jboss.resteasy.reactive.RestResponse
import org.jboss.resteasy.reactive.server.ServerExceptionMapper
import javax.ws.rs.core.MediaType

class ExceptionMappers {

    @ServerExceptionMapper
    fun handleException(exception: Throwable): RestResponse<String> {
        return RestResponse.ResponseBuilder.serverError<String>().entity("ServerExceptionMapper -> Error").type(MediaType.TEXT_PLAIN).build()
    }
}

@Path("/bug")
@ApplicationScoped
class ReproducerResource {

    @GET
    @Path("1")
    @NoCache
    @Produces(RestMediaType.APPLICATION_NDJSON)
    suspend fun reproduceBug(): Flow<String> {
        return flow {
            emit("Test1")
            if (true) {
                throw IllegalArgumentException("IllegalArgumentException -> Error")
            }
        }
    }
}

Output of uname -a or ver

No response

Output of java -version

Java 11

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.9.1.Final

Build tool (ie. output of mvnw --version or gradlew --version)

Maven

Additional information

No response

[quarkus-bot]

/cc @FroMage, @evanchooly, @geoand, @stuartwdouglas

[geoand]

This happens by design for all types that stream data. I'll update https://quarkus.io/guides/resteasy-reactive#streaming-support to make a note of this

[mschorsch]

OK. Thanks. I had already suspected something like that.