Help with Mongoose typings

I’m trying to create typings for Mongoose, but I don’t know if what I want to do is possible.

I want to start simple, so let’s ignore for now all the possible ways to define a model in Mongoose. My goal is to make something like this possible, where looking up a property that wasn’t defined in the schema will error in Flow.

import mongoose from 'mongoose';

const UserSchema = new mongoose.Schema({
  email: {
    type: String, 
    required: true 
  },
  createdAt: { 
    type: Date, 
    default: Date.now 
  },
});

const User = mongoose.model('User', UserSchema);

// And let's run a query

User.findOne({ email: '[e-mail]' }).exec()
  .then((user) => {
    // $ExpectError
    user.lol
  })

This is what I came up with, which doesn’t achieve my goal:

declare class Mongoose$Schema<Schema> {}

type Mongoose$Query<Schema> = {| [$Keys<Schema>]: any |}
type Mongoose$Projection<Schema> = { [$Keys<Schema>]: any }
                                    
declare type Mongoose$Result<Schema> = {| [$Keys<Schema>]: any |}                                   
                                    
declare interface Mongoose$QueryInterface<Schema> {
  exec(): Promise<Mongoose$Result<Schema> | void>
}

declare class Mongoose$Model<Schema> {
  findOne(query: Mongoose$Query<Schema>, projection?: Mongoose$Projection<Schema>): Mongoose$QueryInterface<Schema>
}

Is what I wish to do even possible?

[nodkz]

Who interested in mongoose type defs, please follow PR 1196

[albertorestifo]

Yeah I think this issue can be closed.

Thank you all for the work!