Utils

A handful of small helpers, all available at the top level.

#wait

await nc.wait(500);
await nc.wait("2s");
await nc.wait("1m", { signal: controller.signal }); // rejects with an AbortError if aborted

Durations can be milliseconds or strings like "250ms", "1m30s" and "2h", as everywhere in node-comfort.

#Safe JSON

JSONString() never throws. Circular references become "[Circular]", bigints become strings, Maps become objects and Sets become arrays:

nc.JSONString({ id: 10n, tags: new Set(["a"]) }, 0); // '{"id":"10","tags":["a"]}'

JSONParse() takes a fallback. With one, invalid input returns the fallback instead of throwing:

const settings = nc.JSONParse(raw, {});
const strict = nc.JSONParse(raw); // throws SyntaxError on invalid input

#dontCrash

Keeps a long-running process alive when something unexpected happens. Uncaught exceptions and unhandled rejections are logged instead of killing the process, and SIGINT/SIGTERM are logged before a clean exit:

nc.dontCrash()
  .on("error", (error) => sentry.captureException(error))
  .on("sig", async () => {
    await server.close();
    process.exit(0);
  });

It only ever removes its own handlers; listeners from your code or other libraries stay in place. For a full graceful shutdown with timeouts, see sys.onShutdown().

#when

Checks a condition at an interval and emits events. Remember to call .start():

nc.when(() => queue.length > 0, { reason: "jobs waiting" }, { interval: 500, timeout: 10_000 })
  .on("trigger", (payload) => nc.info(payload.reason))
  .on("timeout", () => nc.warn("Nothing happened in 10s"))
  .start();

To wait until something is true, async.poll() returns a promise and is usually easier.