tracePromise

fun <ThisArg, Args : ReadonlyArray<Any?>> tracePromise(fn: Function<Promise<Any?>>, context: ContextType = definedExternally, thisArg: ThisArg = definedExternally, vararg args: Any?)(source)

Trace a promise-returning function call. This will always produce a start event and end event around the synchronous portion of the function execution, and will produce an asyncStart event and asyncEnd event when a promise continuation is reached. It may also produce an error event if the given function throws an error or the returned promise rejects. This will run the given function using channel.runStores(context, ...) on the start channel which ensures all events should have any bound stores set to match this trace context.

To ensure only correct trace graphs are formed, events will only be published if subscribers are present prior to starting the trace. Subscriptions which are added after the trace begins will not receive future events from that trace, only future traces will be seen.

import diagnostics_channel from 'node:diagnostics_channel';

const channels = diagnostics_channel.tracingChannel('my-channel');

channels.tracePromise(async () => {
// Do something
}, {
some: 'thing',
});

Since

v19.9.0

Return

Chained from promise returned by the given function

Parameters

fn

Promise-returning function to wrap a trace around

context

Shared object to correlate trace events through

thisArg

The receiver to be used for the function call

args

Optional arguments to pass to the function