InferRawDocType not same type return from .lean()

[mezozawahra]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.5.3

Node.js version

19.8

MongoDB server version

7.0.12

Typescript version (if applicable)

No response

Description

when I use type returned by InferRawDocType it is supposed to be the same as the type returned from function .lean(), but using the document from then() it throws a type error, reproducsible code below

Steps to Reproduce

import mongoose
const schemaDefinition = {
  email : { 
    type : String ,
    trim: true,
    required : true,
    unique: true,
    lowercase: true
  },
  password : {
    type : String ,
    required : true,
  },
  dateOfBirth: {
    type: Date,
    required: true
  }
}

const UserModel = mongoose.model('User' , UserSchema);
type UserType = mongoose.InferRawDocType< typeof schemaDefinition>;

let user: UserType | null;

async function queryById(id: string ){
    let user: UserType | null ;
    UserModel.findById(id).lean().then( result=>{
        if (result){
            user = result
        }
    })
}

this code gives type error

Type 'FlattenMaps<{ email: string; password: string; firstName: string; lastName: string; dateOfBirth: Date; }> & { _id: ObjectId; }' is not assignable to type '{ email: string; password: string; firstName: string; lastName: string; dateOfBirth: Date; } | null'.
  Type 'FlattenMaps<{ email: string; password: string; firstName: string; lastName: string; dateOfBirth: Date; }> & { _id: ObjectId; }' is not assignable to type '{ email: string; password: string; firstName: string; lastName: string; dateOfBirth: Date; }'.
    Types of property 'dateOfBirth' are incompatible.
      Type 'Date' is missing the following properties from type 'Date': expires, max, min, defaultOptions, and 21 more.

Also whenever i use user._id it throws error Property '_id' does not exist on type '{ email: string; password: string; firstName: string; lastName: string; dateOfBirth: Date; }

Expected Behavior

No response

[vkarpov15]

Is there somewhere in the Mongoose docs where it indicates that InferRawDocType should match the return value from lean()?

[mezozawahra]

@vkarpov15
in the doc it says

If you need to explicitly get the raw document type (the value returned from doc.toObject(), await Model.findOne().lean(), etc.) from your schema definition, you can use Mongoose's inferRawDocType helper as follows:

Tbh,I am not sure if it's just a bug or I misunderstood it either way thank you for your time

[vkarpov15]

Ah you're right, I misunderstood. We'll investigate.