Automattic/mongoose · error · Error

Can't populate individual element in an array

Error message

Can't populate individual element in an array

What it means

Error "Can't populate individual element in an array" thrown in Automattic/mongoose.

Source

Thrown at lib/helpers/populate/modelNamesFromRefPath.js:34

  if (typeof refPath !== 'string') {
    throw new MongooseError('`refPath` must be a string or a function that returns a string, got ' + util.inspect(refPath));
  }

  if (queryProjection != null && isPathExcluded(queryProjection, refPath)) {
    throw new MongooseError('refPath `' + refPath + '` must not be excluded in projection, got ' +
      util.inspect(queryProjection));
  }

  // If populated path has numerics, the end `refPath` should too. For example,
  // if populating `a.0.b` instead of `a.b` and `b` has `refPath = a.c`, we
  // should return `a.0.c` for the refPath.

  if (hasNumericPropRE.test(populatedPath)) {
    const chunks = populatedPath.split(hasNumericPropRE);

    if (chunks[chunks.length - 1] === '') {
      throw new Error('Can\'t populate individual element in an array');
    }

    let _refPath = '';
    let _remaining = refPath;
    // 2nd, 4th, etc. will be numeric props. For example: `[ 'a', '.0.', 'b' ]`
    for (let i = 0; i < chunks.length; i += 2) {
      const chunk = chunks[i];
      if (
        _remaining.length >= chunk.length + 1 &&
        _remaining.charAt(chunk.length) === '.' &&
        _remaining.slice(0, chunk.length) === chunk
      ) {
        _refPath += _remaining.substring(0, chunk.length) + chunks[i + 1];
        _remaining = _remaining.substring(chunk.length + 1);
      } else if (i === chunks.length - 1) {
        _refPath += _remaining;
        _remaining = '';
        break;

View on GitHub (pinned to 49cdab0136)

When it happens

Trigger: Thrown at lib/helpers/populate/modelNamesFromRefPath.js:34 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/48135d80af7d9d79. Report an issue: GitHub.