When using a Map of Mixed (mongoose.Schema.Types.mixed) types in a subschema, a TypeError is thrown when trying to update or assign a value to a nested property of that mixed type using updateOne() or findOneAndUpdate().

[dl3061]

Prerequisites

• I have written a descriptive issue title

Mongoose version

6.6.4

Node.js version

18.8.0

MongoDB version

4.2.20

Operating system

No response

Operating system version (i.e. 20.04, 11.3, 10)

No response

Issue

When using a Map of Mixed (mongoose.Schema.Types.mixed) types in a subSchema, a TypeError is thrown when trying to update or assign a value to a nested property of that mixed typo using updateOne() or findOneAndUpdate().

One field I have in a schema is a generic 'properties', that's a type Map of Schema.Types.Mixed.

When this 'properties' field is on a top-level schema, I can $set values in it without issue, including nested values:

$set: {
  'properties.hello': 'world',
  'properties.foo.bar': 1,
  'properties.foo.baz': 2,
},

However, when this 'properties' field is in a nested child schema, I'm seeing an error when trying to $set nested values within that properties.

$set: {
  'child.properties.hello': 'world', // works if it's just this
  'child.properties.foo.bar': 1, // added this nested property causes the error below
  'child.properties.foo.baz': 2,
},

The issue I'm seeing is:

%PROJECT_DIR%\node_modules\mongoose\lib\schema.js:2289
      foundschema = schema.path(trypath);

TypeError: Cannot read properties of undefined (reading 'path')
    at search (%PROJECT_DIR%\node_modules\mongoose\lib\schema.js:2289:28)
    at search (%PROJECT_DIR%\node_modules\mongoose\lib\schema.js:2339:23)
    at Schema._getSchema (%PROJECT_DIR%\node_modules\mongoose\lib\schema.js:2358:10)
    at walkUpdatePath (%PROJECT_DIR%\node_modules\mongoose\lib\helpers\query\castUpdate.js:313:27)
    at castUpdate (%PROJECT_DIR%\node_modules\mongoose\lib\helpers\query\castUpdate.js:97:7)
    at model.Query._castUpdate (%PROJECT_DIR%\node_modules\mongoose\lib\query.js:5104:10)
    at Query._findAndModify (%PROJECT_DIR%\node_modules\mongoose\lib\query.js:3989:29)
    at model.Query.<anonymous> %PROJECT_DIR%\node_modules\mongoose\lib\query.js:3470:8)
    at model.Query._wrappedThunk [as _findOneAndUpdate] (%PROJECT_DIR%\node_modules\mongoose\lib\helpers\query\wrapThunk.js:29:8)
    at %PROJECT_DIR%\node_modules\kareem\index.js:426:25

I included a script that could reproduce the issue:
The parent schema includes one of these 'properties' fields and an instance of a child schema which in turn also includes one of these 'properties' fields.

• The script will create a document using the parent schema.
• Then, it will use $set a few fields within that parent's properties map, including one with a nested value.
• Then, it will try to $set a few fields within that child's properties map, including one with a nested value. (I see the error being thrown here)

import mongoose from 'mongoose';

const childSchema = new mongoose.Schema({
  properties: {
    type: Map,
    of: mongoose.Schema.Types.Mixed,
    required: true,
    default: {},
  },
});

const parentSchema = new mongoose.Schema({
  username: {
    type: String,
    required: true,
  },
  properties: {
    type: Map,
    of: mongoose.Schema.Types.Mixed,
    required: true,
    default: {},
  },
  child: {
    type: childSchema,
    required: true,
  },
});

async function main() {
  const mongooseConnection = mongoose.createConnection('mongodb://0.0.0.0:27017/test');
  const TestModel = mongooseConnection.model('Test', parentSchema);

  await TestModel.deleteMany({});

  const username = 'TestUser';
  await TestModel.create({
    username,
    child: {},
  });

  console.log(`beforeUpdate:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);

  // Update parent.properties
  await TestModel.updateOne(
    { username },
    {
      $set: {
        'properties.age': 'eleven',
        'properties.foo.bar': 1,
      },
    },
    { runValidators: true },
  );
  console.log(`afterUpdateParent:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);

  // Update child properties
  await TestModel.findOneAndUpdate(
    {
      username,
    },
    {
      $set: {
        'child.properties.test': 'ing',
        'child.properties.foo.bar': 'ing',
      },
    },
    { runValidators: true },
  );
  console.log(`afterUpdateChild:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);
}

main();

Is this a bug, or is there a better way I should be setting up this schema and making calls to update values within that schema, including that properties value?

Thanks in advance!

[IslandRhythms]

const mongoose = require('mongoose');

const childSchema = new mongoose.Schema({
  properties: {
    type: Map,
    of: mongoose.Schema.Types.Mixed,
    required: true,
    default: {},
  },
});

const parentSchema = new mongoose.Schema({
  username: {
    type: String,
    required: true,
  },
  properties: {
    type: Map,
    of: mongoose.Schema.Types.Mixed,
    required: true,
    default: {},
  },
  child: {
    type: childSchema,
    required: true,
  },
});

async function main() {
  const mongooseConnection = mongoose.createConnection('mongodb://0.0.0.0:27017/test');
  mongoose.connection.dropDatabase();
  const TestModel = mongooseConnection.model('Test', parentSchema);

  await TestModel.deleteMany({});

  const username = 'TestUser';
  await TestModel.create({
    username,
    child: {},
  });

  console.log(`beforeUpdate:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);

  // Update parent.properties
  await TestModel.updateOne(
    { username },
    {
      $set: {
        'properties.age': 'eleven',
        'properties.foo.bar': 1,
      },
    },
    { runValidators: true },
  );
  console.log(`afterUpdateParent:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);

  // Update child properties
  await TestModel.findOneAndUpdate(
    {
      username,
    },
    {
      $set: {
        'child.properties.test': 'ing',
        'child.properties.foo.bar': 'ing',
      },
    },
    { runValidators: true },
  );
  console.log(`afterUpdateChild:\n ${JSON.stringify(await TestModel.findOne({ username }).lean(), null, 2)}\n`);
}

main();