Automattic/mongoose · error · MongooseError

Model.populate() no longer accepts a callback

Error message

Model.populate() no longer accepts a callback

What it means

Error "Model.populate() no longer accepts a callback" thrown in Automattic/mongoose.

Source

Thrown at lib/model.js:4480

 * @param {boolean} [options.retainNullValues=false] By default, Mongoose removes null and undefined values from populated arrays. Use this option to make `populate()` retain `null` and `undefined` array entries.
 * @param {boolean} [options.getters=false] If true, Mongoose will call any getters defined on the `localField`. By default, Mongoose gets the raw value of `localField`. For example, you would need to set this option to `true` if you wanted to [add a `lowercase` getter to your `localField`](https://mongoosejs.com/docs/schematypes.html#schematype-options).
 * @param {boolean} [options.clone=false] When you do `BlogPost.find().populate('author')`, blog posts with the same author will share 1 copy of an `author` doc. Enable this option to make Mongoose clone populated docs before assigning them.
 * @param {object|Function} [options.match=null] Add an additional filter to the populate query. Can be a filter object containing [MongoDB query syntax](https://www.mongodb.com/docs/manual/tutorial/query-documents/), or a function that returns a filter object.
 * @param {boolean} [options.skipInvalidIds=false] By default, Mongoose throws a cast error if `localField` and `foreignField` schemas don't line up. If you enable this option, Mongoose will instead filter out any `localField` properties that cannot be casted to `foreignField`'s schema type.
 * @param {number} [options.perDocumentLimit=null] For legacy reasons, `limit` with `populate()` may give incorrect results because it only executes a single query for every document being populated. If you set `perDocumentLimit`, Mongoose will ensure correct `limit` per document by executing a separate query for each document to `populate()`. For example, `.find().populate({ path: 'test', perDocumentLimit: 2 })` will execute 2 additional queries if `.find()` returns 2 documents.
 * @param {boolean} [options.strictPopulate=true] Set to false to allow populating paths that aren't defined in the given model's schema.
 * @param {object} [options.options=null] Additional options like `limit` and `lean`.
 * @param {Function} [options.transform=null] Function that Mongoose will call on every populated document that allows you to transform the populated document.
 * @param {boolean} [options.forceRepopulate=true] Set to `false` to prevent Mongoose from repopulating paths that are already populated
 * @param {boolean} [options.ordered=false] Set to `true` to execute any populate queries one at a time, as opposed to in parallel. Set this option to `true` if populating multiple paths or paths with multiple models in transactions.
 * @return {Promise}
 * @api public
 */

Model.populate = async function populate(docs, paths) {
  _checkContext(this, 'populate');
  if (typeof paths === 'function' || typeof arguments[2] === 'function') {
    throw new MongooseError('Model.populate() no longer accepts a callback');
  }
  // normalized paths
  paths = utils.populate(paths);

  if (paths.length === 0) {
    return docs;
  }

  // each path has its own query options and must be executed separately
  if (paths.find(p => p.ordered)) {
    // Populate in series, primarily for transactions because MongoDB doesn't support multiple operations on
    // one transaction in parallel.
    // Note that if _any_ path has `ordered`, we make the top-level populate `ordered` as well.
    for (const path of paths) {
      await _populatePath(this, docs, path);
    }
  } else {
    // By default, populate in parallel

View on GitHub (pinned to 49cdab0136)

When it happens

Trigger: Thrown at lib/model.js:4480 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Automattic/mongoose@49cdab0136 (2026-08-21). Data as JSON: /api/errors/726842a2d9d9df4f. Report an issue: GitHub.