What causes "No callback function supplied" in denoland/deno?

Use fs.promises.lutimes(path, atime, mtime) for promise-style code

denoland/deno · error · Error

No callback function supplied

Error message

No callback function supplied

What it means

fs.lutimes(path, atime, mtime, callback) throws this plain Error (no code) when callback is falsy. Unlike lstat/readdir it has no options overload, so exactly four arguments are expected; calling it with three (or with a missing/undefined callback) always trips this guard before any time validation happens.

Source

Thrown at ext/node/polyfills/_fs/_fs_lutimes.ts:60

  const unixSeconds = toUnixTimestamp(value);

  const seconds = MathTrunc(unixSeconds);
  const nanoseconds = MathTrunc((unixSeconds * 1e3) - (seconds * 1e3)) * 1e6;

  return [
    seconds,
    nanoseconds,
  ];
}

export function lutimes(
  path: PathLike,
  atime: TimeLike,
  mtime: TimeLike,
  callback: CallbackWithError,
): void {
  if (!callback) {
    throw new Error("No callback function supplied");
  }
  const { 0: atimeSecs, 1: atimeNanos } = getValidUnixTime(atime, "atime");
  const { 0: mtimeSecs, 1: mtimeNanos } = getValidUnixTime(mtime, "mtime");

  path = getValidatedPathToString(path);

  PromisePrototypeThen(
    op_node_lutimes(path, atimeSecs, atimeNanos, mtimeSecs, mtimeNanos),
    () => callback(null),
    callback,
  );
}

export function lutimesSync(
  path: PathLike,
  atime: TimeLike,
  mtime: TimeLike,
): void {

View on GitHub (pinned to 89f33cbef2)

Solutions

Use fs.promises.lutimes(path, atime, mtime) for promise-style code
Otherwise pass a fourth function argument: fs.lutimes(path, atime, mtime, err => { ... })
In wrappers, assert typeof args[3] === 'function' before delegating

Example fix

// before
fs.lutimes(path, atime, mtime);

// after
await fs.promises.lutimes(path, atime, mtime);
// or
fs.lutimes(path, atime, mtime, (err) => { if (err) throw err; });

Defensive patterns

Strategy: validation

Validate before calling

if (typeof callback !== 'function') {
  throw new Error('lutimes(path, atime, mtime, callback) requires a 4th callback argument');
}

Type guard

const isCallback = (v) => typeof v === 'function';

Prevention

Use fs.promises.lutimes for promise-style code
lutimes has no options overload — the 4th positional argument is always the callback
Let TypeScript's arity checking catch missing arguments

When it happens

Trigger: fs.lutimes(path, atime, mtime) with no fourth argument; destructuring a callback from an object that does not define it and passing undefined.

Common situations: Switching from fs.promises.lutimes to fs.lutimes and dropping the callback; writing a wrapper that forwards (...args) but callers omit the last one.

Related errors

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/c5277b1d548fbc29. Report an issue: GitHub.