Exception in Route.handle is handled silently

Unhandled exceptions are usually printed (afaik) but the IllegalArgumentException here isnt. My guess would be it should always be printed.

class Blocking(environment: ApplicationEnvironment) : Application(environment) {
    init {
        routing {
            method(HttpMethod.Post){
                route("/exception") {
                    handle {
                        println("exception")
                        throw IllegalArgumentException()
                    }
                }
                route("/exception2") {
                    handle {
                        println("exception2")
                        subject.respondWrite {
                            throw IllegalArgumentException()
                        }
                    }
                }
            }
        }
    }
}

class ExceptionEater {

    @Test
    fun foo(){
        val port = 44003
        val appHostConfig = applicationHostConfig { connector { this.port = port } }
        val appEnv = BasicApplicationEnvironment(javaClass.classLoader, SLF4JApplicationLog("KTorTest"), MapApplicationConfig(
                "ktor.application.class" to Blocking::class.qualifiedName!!
        ))
        val jetty = JettyApplicationHost(appHostConfig, appEnv)
        jetty.start()
        val paths = listOf("exception", "exception2")
        val e = Executors.newCachedThreadPool()
        paths.map { path ->
            e.submit(Callable {
                val c = URL("http://localhost:$port/$path").openConnection() as HttpURLConnection
                c.doOutput = true
                c.outputStream.apply {
                    write("Foo".toByteArray(StandardCharsets.UTF_8))
                    flush()
                }
                c.inputStream.bufferedReader().readLine().apply {
                    println("Done")
                }
            })
        }

        TimeUnit.SECONDS.sleep(10)
    }
}

[kyegupov]

CallLogger currently does not work as it should: https://github.com/Kotlin/ktor/issues/50

On top of that, swallowing exceptions silently by default is a very bad practice, resulting in an incredibly hostile learning curve.

Perhaps tutorial-mode setups like embeddedJettyServer(routing = ...).start() should have it baked in by default, with logging to stdout/stderr preconfigured?

[orangy]

I verified this case in our new coroutine-based implementation and everything is good (given CallLogging is installed)