Property 'x' does not exist on type Ref

[mad-coder-365]

I am getting stuck with this basic error. Need help!

I have two classes

class Classroom {
  @prop()
  name: string;
}

class User {
  @prop()
  username: string;

  @prop(ref: () => Classroom)
  classId: Classroom;
}

When I map over array like

const users: User[] = userModel.find({}).populate('classId')  // classId is getting populated. This is working.

const usersInfo = users.map((user: User) => {
  return {
    id: user._id,
    className: user.classId.name
  }
})

I get two errors:

TS2339: Property '_id' does not exist on type 'User'.

TS2339: Property 'name' does not exist on type 'Ref<Classroom, ObjectId>'.   Property 'name' does not exist on type 'ObjectId'.

For the first error do I have to do something like:

public readonly _id: Types.ObjectId;

Best way to solve these errors? Thanks

[hasezoey]

classId: Classroom;

you are using the wrong type, it is Ref<Class>

TS2339: Property '_id' does not exist on type 'User'.
TS2339: Property 'name' does not exist on type 'Ref<Classroom, ObjectId>'. Property 'name' does not exist on type 'ObjectId'.

you need to use typeguards, because a reference can be multiple types read Reference other Classes: Population or API: typeguards: isDocument & isDocumentArray

PS: in case you are not on typegoose 10, you maybe need to shadow _id as a property in your class if you want access to it, like:

class YourClass {
  public _id?: mongoose.Types.ObjectId; // dont forget to NOT put a "@prop" decorator on this, otherwise you will be overwriting all defaults
}

[mad-coder-365]

Thanks rookie mistake 😁

[mad-coder-365]

I am on typegoose 10 but I think I referenced the class wrong. I will check.

[mad-coder-365]

@hasezoey I am on typegoose 10. I am still getting an error TS2339: Property '_id' does not exist on type User. If I shadow _id like you mentioned it works.

[hasezoey]

if you still get the error, then it is the problem of your re-casting of the type user: User at users.map((user: User), just remove the type-recasting and you should get the proper type
Note: i didnt notice this recasting while doing my first answer

Edit: i also just noticed you also re-cast the type with users: User[] at const users: User[], also dont do that, or use the proper type of users: DocumentType<User>[] | null

[mad-coder-365]

Makes sense, thanks :)