Typescript interface on mongoose populate

Question

So I have this mongoose model as below:

const userSchema: mongoose.Schema = new mongoose.Schema(
    {
        _id: String,
        email: {
            type: String,
            required: true,
        },
        firstName: String,
        lastName: String,       
        phoneNumber: String,
        cmt: {
            type: String,
            ref: 'Cmt',
        },      
    },  
);

As you can see cmt field is pointing to another model called Cmt whose details I'll be getting used populate

now on another instance i need to pass in the cmt id for linking it with the userSchema

but at that time i'll get a typescript error of "Type 'string' is not assignable to type 'ICmt'."

ICmt being the interface definition of Cmt.

The userschema interface is given below.

export interface IUser {
    _id: string;
    email: string;
    firstName: string;
    lastName: string;
    phoneNumber: string;
    cmt: ICmt;
    createdAt?: Date;
    updatedAt?: Date;
}

How can I fix this error without messing both populate query and create query?

Answer 1

This was an easy solution, wrong on my end.

You could use an | (or) statement on the interface, that will solve the problem for the tslint errors that may occur

So my user interface will become

export interface IUser {
    _id: string;
    email: string;
    firstName: string;
    lastName: string;
    phoneNumber: string;
    cmt: ICmt | string;
    createdAt?: Date;
    updatedAt?: Date;
}

So there won't be any more tslint errors or tsignore that I need to worry about

Answer 2

The following will work, but will require type checking for either case.

export interface User {  // Issue when using I in declarations v.6++
  cmt: Cmt | mongoose.Types.ObjectID;
}