MongoServerError: Invalid $set :: caused by :: Unrecognized expression '$sortArray

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

6.4.7

Node.js version

16

MongoDB server version

6

Description

Is $sortArray supported?

We’re building a document tracking system and need to sort an array of changes (think of them as individual “git” commits).

Error:    MongoServerError: Invalid $set :: caused by :: Unrecognized expression '$sortArray'

Steps to Reproduce

[
{
    _id: ObjectId('631c63f50ec04fed51a687dc'),
    createdAt: "2022-09-10T10:38:24.791Z"
    changes: [
        {
            fullDocument: {
                _change: {
                    user: UUID("78a7bfaf173b460d84b34cca4aa12c03"),
                    operation: 'addArea',
                    seq: 0,
                },
            },
        },
        {
            fullDocument: {
                _change: {
                    user: UUID("78a7bfaf173b460d84b34cca4aa12c03"),
                    operation: 'updateCountry',
                    seq: 1,
                },
            },
        }
    ],
}
...
]

Code

      const rs2 = await this.changelogModel
        .aggregate([
          filter,
          {
            $set: {
              changes: {
                $sortArray: {
                  input: '$changes',
                  sortBy: { 'fullDocument._change.seq': -1 }
                }
              }
            }
          },

Expected Behavior

$sortArray is working

Edit: add createdAt timestamp to example data

[vnugent]

You’re right. We’re using hosted mongo on DigitalOcean and I thought we’re on v6, but it’s actually 5.0.8. Let me open a support ticket to see if it’s possible to upgrade.

Thanks so much for your time.

[AbdelrahmanHafez]

@vnugent This is probably an issue with your MongoDB server version, it does not support $sortArray yet, you probably need to update it. Please try to run the following script and see if it fails for you, and share the output in this issue.

12415.js

'use strict';
const mongoose = require('mongoose');
const assert = require('node:assert');
const { Schema } = mongoose;

const changeLogSchema = new Schema({
  bandName: String,
  tours: [{
    date: Date,
    location: String
  }]
});


const ChangeLog = mongoose.model('change_logs', changeLogSchema);

run().catch(console.error);

async function run() {
  // Arrange
  await mongoose.connect('mongodb://localhost:27017/test');
  await mongoose.connection.dropDatabase();
  const admin = new mongoose.mongo.Admin(mongoose.connection.db);
  const buildInfo = await admin.buildInfo();
  console.log('MongoDB server version', buildInfo.version);

  await ChangeLog.insertMany([
    {
      bandName: 'B',
      tours: [
        { date: new Date('2022-09-15T10:38:24.791Z'), location: 'San Francisco' },
        { date: new Date('2022-09-10T10:38:24.791Z'), location: 'Seatle' }
      ]
    },
    {
      bandName: 'A',
      tours: [
        { date: new Date('2022-09-15T10:38:24.791Z'), location: 'San Francisco' },
        { date: new Date('2022-09-10T10:38:24.791Z'), location: 'Seatle' }
      ]
    }]);
  // Act
  const docs = await ChangeLog.aggregate([
    {
      $sort: {
        bandName: 1
      }
    },
    {
      $set: {
        tours: {
          $sortArray: {
            input: '$tours',
            sortBy: {
              date: 1
            }
          }
        }
      }
    }
  ]);

  // Assert
  assert.strictEqual(docs[0].bandName, 'A');
  assert.strictEqual(docs[1].bandName, 'B');
  assert.strictEqual(docs[0].tours[0].location, 'Seatle');
  assert.strictEqual(docs[1].tours[0].location, 'Seatle');
  console.log('Assertion passed');
  console.log('Mongoose version', mongoose.version);
}

Output

$ node 12415.js
MongoDB server version 6.0.1
Assertion passed
Mongoose version 6.6.0

You can test with mongo 6 locally using Docker:

docker container run -p 27017:27017 mongo:6