Mongoose: Bug in version 5.10.7 - ValidationError this[documentIsSelected] is not a function

[Adam-Edry]

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

What is the current behavior?
Failing to create documents in many of my collections. Receiving the following error:

ValidationError: projects validation failed: name: this[documentIsSelected] is not a function

where projects is the collection name.

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

I don't have steps to reproduce. I suspect this is related to having required in the schema due to the latest changes in history.md:

fix(document): pass document to required validator so required can use arrow functions #9435 AbdelrahmanHafez
fix(document): handle required when schema has property named isSelected #9438

I'll try to provide a gist or script when I get off of work today if no one comes up with anything until then.

What is the expected behavior?
Should be able to create a document in a collection using the create function.

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.
Mongoose: 5.10.7
MongoDB: 4.2.9
Node.js: 10.16.3

Note: I downgraded to mongoose 5.10.6 and that is working fine.

[Adam-Edry]

Reproduced:
https://gist.github.com/Adam-Edry/b6523c461c4017c662948869724fcdd8

gists won't allow me to have directories so I substituted _ for the directory.
We have 2 dirs test-mongoose and depend-package each is a node.js package.
After you go into test-mongoose, npm install and then run node index.js you should see the error

This seems to happen because the mongoose module being used in the dependency package is not the same one as the primary package (test-mongoose). Are there any globals used when we create a schema?

The offending line is mongoose/lib/schemaType.js:921 and logging there shows that this[documentIsSelected] is undefined.

Let me know if I can be of further help

[eilinora]

+ 1

Seeing this as well, when my Schema has required on one of its field (even when data is provided) validation fails.

Downgrading to 5.10.6 fixed the problem

[luisenrike]

The problem was introduced here:

https://github.com/Automattic/mongoose/commit/b128c9bf21b4d4edce09d39b0f9fbd5741f3e800#diff-020b22edc836e4a997579b91daed76b9R8-R10

exports.documentIsSelected = Symbol('mongoose#Document#isSelected');
exports.documentIsModified = Symbol('mongoose#Document#isModified');
exports.documentModifiedPaths = Symbol('mongoose#Document#modifiedPaths');

We are requiring mongoose from two different packages so they don't share the symbols registry. That's why you get ValidationError: projects validation failed: name: this[documentIsSelected] is not a function

a.js

module.exports = Symbol('foo')

b.js

module.exports = Symbol('foo')

index.js

const fooA = require('./a')
const fooB = require('./b')

fooA === fooB // === false

Using Symbol.for fixes the problem but I don't know if this is the best way to do it 🤔.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/for

[vkarpov15]

Thanks for the repro and sorry for the difficulty. We worked around this issue by ensuring that documents don't end up with a schema that's tied to a different mongoose module. When you call mongoose.model() with a schema from a different mongoose module, we'll instantiate a new schema that's tied to the mongoose from mongoose.model().

[vkarpov15]

As a side note, if you have a separate module that stores your schemas, you should consider listing Mongoose in peerDependencies rather than dependencies, so you minimize the risk of version mismatch.