mongoose-id-validator | Mongoose plug in to validate ObjectID references point | DB Client library

modules, phases, tasks are Arrays. You can't call req.body.structure.modules.phases.tasks

req.body.structure.modules is an array req.body.structure.modules.phases doesn't exist and is undefined.

A better way to assign properties like this:

I managed to reproduce this using the following order of schema/model setup:

1. create the CartItemSchema schema
2. create the CartSchema schema
3. create the Cart model
4. add the calculateTotals methods to CartItemSchema
5. create the CartItem model

Step #4 is the culprit: you're modifying a schema that's already being used by a model (indirectly, by Cart).

The correct order (or at least, the order that should yield the least amount of issues) should be:

1. create the CartItemSchema schema
2. add the calculateTotals methods to CartItemSchema
3. create the CartItem model
4. create the CartSchema schema
5. create the Cart model