@Test
    fun test() = testApplication {
        externalServices {
            hosts("<wss://test.com>") {
                install(io.ktor.server.websocket.WebSockets) { }

                routing {
                    webSocket("/test") {
                        send(Frame.Text("hello"))
                    }
                }
            }
        }

        val client = createClient {
            install(WebSockets) {
                contentConverter = KotlinxWebsocketSerializationConverter(
                    Json {
                        ignoreUnknownKeys = true
                    }
                )
            }
        }

        runBlocking {
            client.wss(host = "<http://test.com|test.com>", path = "test") {
                val string = Json.encodeToString(User("foo"))
//                     val string = """{"name":"foo"}"""
                println(string)
                send(Frame.Text(string))
            }
        }
    }

{"name":"foo"}

java.util.concurrent.CancellationException: ArrayChannel was cancelled

string