Automattic/mongoose · error · MongooseError

AggregationCursor.prototype.close() no longer accepts a call

Error message

AggregationCursor.prototype.close() no longer accepts a callback

What it means

Mongoose 7 removed callback support, mirroring the MongoDB driver. AggregationCursor#close() is now an async method returning a Promise; passing a function as the first argument throws immediately so legacy call sites fail loudly instead of silently never invoking the callback.

Source

Thrown at lib/cursor/aggregationCursor.js:240

AggregationCursor.prototype._markError = function(error) {
  this._error = error;
  return this;
};

/**
 * Marks this cursor as closed. Will stop streaming and subsequent calls to
 * `next()` will error.
 *
 * @return {Promise}
 * @api public
 * @method close
 * @emits "close"
 * @see AggregationCursor.close https://mongodb.github.io/node-mongodb-native/7.0/classes/AggregationCursor.html#close
 */

AggregationCursor.prototype.close = async function close() {
  if (typeof arguments[0] === 'function') {
    throw new MongooseError('AggregationCursor.prototype.close() no longer accepts a callback');
  }
  try {
    await this.cursor.close();
  } catch (error) {
    this.listeners('error').length > 0 && this.emit('error', error);
    throw error;
  }
  this.emit('close');
};

/**
 * Marks this cursor as destroyed. Will stop streaming and subsequent calls to
 * `next()` will error.
 *
 * @return {this}
 * @api private
 * @method _destroy
 */

View on GitHub (pinned to 49cdab0136)

Solutions

Replace cursor.close(cb) with await cursor.close() and handle errors with try/catch or .catch()
If a callback API must be kept outward, shim it: cursor.close().then(() => cb(null), cb)
During the Mongoose 7 migration, sweep the codebase for cursor close calls that pass a function

Example fix

// before
aggCursor.close(function (err) {
  if (err) console.error(err);
});

// after
try {
  await aggCursor.close();
} catch (err) {
  console.error(err);
}

Defensive patterns

Strategy: validation

Validate before calling

function closeCursor(cursor, ...args) {
  if (args.some(a => typeof a === 'function')) {
    throw new TypeError('close() takes no callback; await the returned promise');
  }
  return cursor.close();
}

Prevention

Never pass functions to cursor lifecycle methods in Mongoose 7+ code
Run a migration grep for callback-style cursor calls before upgrading major versions
Keep cursor utilities promise-only and wrap at the edge if legacy callback callers exist

When it happens

Trigger: aggCursor.close(() => {}) or aggCursor.close(function (err) {...}) — any function passed as the first argument to close().

Common situations: Upgrading an app from Mongoose 6 or earlier to 7+ without migrating cursor code; copy-pasting pre-2022 tutorials that use the callback style.

Related errors

AI-assisted analysis of Automattic/mongoose@49cdab0136 (2026-08-21). Data as JSON: /api/errors/65fcc3d21632c7ad. Report an issue: GitHub.