Processing Maps can result in calling doValidate on undefined values + unclear error message

[hasezoey]

Do you want to request a feature or report a bug?
bug

What is the current behavior?
Error on calling create

Error:

TypeError: Cannot read properties of undefined (reading 'validate')
    at SubdocumentPath.doValidate (/mnt/projects/nodejs/typegoose-testing/node_modules/mongoose/lib/schema/SubdocumentPath.js:247:18)
    at /mnt/projects/nodejs/typegoose-testing/node_modules/mongoose/lib/document.js:2719:18
    at processTicksAndRejections (node:internal/process/task_queues:78:11)

If the current behavior is a bug, please provide the steps to reproduce.

// NodeJS: 17.6.0
// MongoDB: 4.2-bionic (Docker)
import * as mongoose from 'mongoose'; // mongoose@6.2.4

const schema_resourceparameter = new mongoose.Schema(
  {
    value: {
      type: mongoose.Schema.Types.Mixed,
    },
  },
  { collection: 'ResourceParameter' }
);

const schema_resource = new mongoose.Schema({
  parameters: {
    type: Map,
    of: schema_resourceparameter,
  },
});

const schema_objectnested = schema_resource.clone();
schema_objectnested.set('collection', 'ObjectNested');

const schema_objectmain = schema_resource.clone();
schema_objectmain.set('collection', 'ObjectMain');
schema_objectmain.add({
  object_nested: {
    type: schema_objectnested,
  },
});

class ResourceParameter {
  public value?: any;
}

class Resource {
  public parameters: Map<string, ResourceParameter> = new Map();
}

class ObjectNested extends Resource {
  private dummy?: never;
}

class ObjectMain extends Resource {
  public object_nested?: ObjectNested;
}

const ObjectMainModel = mongoose.model('ObjectMain', schema_objectmain);

(async () => {
  await mongoose.connect(`mongodb://localhost:27017/`, {
    dbName: 'verifyMASTER',
  });

  const objectMain = new ObjectMain();

  const resourceParameter1 = new ResourceParameter();
  resourceParameter1.value = 'Hello I am a nested resource parameter';
  objectMain.parameters.set('param1', resourceParameter1);

  objectMain.object_nested = new ObjectNested();

  const resourceParameter2 = new ResourceParameter();
  resourceParameter2.value = 'Hello I am a nested resource parameter';
  objectMain.object_nested.parameters.set('param2', resourceParameter2);

  console.log('before create');

  await ObjectMainModel.create(objectMain); // TypeError: Cannot read properties of undefined (reading 'validate')

  await mongoose.disconnect();
})();

reproduction repository & branch: https://github.com/typegoose/typegoose-testing/tree/verify678

What is the expected behavior?
No Error and successful insertion

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
mongoose: 6.2.4
nodejs: 17.6.0

---

Extra information:
when adding console.log("doValidate", value, fn, scope, options); just before the error in mongoose code (meaning just before return value.validate(fn); in SubdocumentPath.prototype.doValidate)

i get the following values:

doValidate undefined [Function (anonymous)] {
  parameters: Map(1) {
    'param1' => {
      value: 'Hello I am a nested resource parameter',
      _id: new ObjectId("6227303b2a04a004bc9592d1")
    }
  },
  _id: new ObjectId("6227303b2a04a004bc9592d0"),
  object_nested: {
    parameters: Map(1) { 'param2' => [Object] },
    _id: new ObjectId("6227303b2a04a004bc9592d2")
  }
} {
  skipSchemaValidators: true,
  path: 'parameters.param2',
  validateModifiedOnly: undefined
}

---

Original issue was a typegoose issue: typegoose/typegoose#678

[IslandRhythms]

Does not error on previous version of mongoose 6.0.x

[vkarpov15]

Thanks for the detailed repro script. Fix will be in 6.2.8 👍