triggerAsyncId

external fun triggerAsyncId(): Double(source)
const server = net.createServer((conn) => {
// The resource that caused (or triggered) this callback to be called
// was that of the new connection. Thus the return value of triggerAsyncId()
// is the asyncId of "conn".
async_hooks.triggerAsyncId();

}).listen(port, () => {
// Even though all callbacks passed to .listen() are wrapped in a nextTick()
// the callback itself exists because the call to the server's .listen()
// was made. So the return value would be the ID of the server.
async_hooks.triggerAsyncId();
});

Promise contexts may not get valid triggerAsyncIds by default. See the section on promise execution tracking.

Return

The ID of the resource responsible for calling the callback that is currently being executed.