| Fix the following issue: | |
| ts def of updateOne&findOneAndUpdate returns FlattenMap instead of UpdateWriteOpResult, when lean() is used | |
| ### Prerequisites | |
| - [X] I have written a descriptive issue title | |
| - [X] I have searched existing issues to ensure the bug has not already been reported | |
| ### Mongoose version | |
| 7.1.0 | |
| ### Node.js version | |
| 16.20 | |
| ### MongoDB server version | |
| 5.x | |
| ### Typescript version (if applicable) | |
| 4.9.5 | |
| ### Description | |
| I tried upgrading to mongoose 7.x, but now I'm stuck with some typescript issues. | |
|  | |
| somehow updateOne returns a FlattenMap and not the ResultType defined in updateOne: | |
|  | |
| I would expect a UpdateWriteOpResult here. | |
| ### Steps to Reproduce | |
| my UserModel is defined as | |
| ``` | |
| const userSchema = new Schema({...}); | |
| export interface IDBUser { .. }; | |
| const DBUserModel: Model<IDBUser> = model<IDBUser>('User', userSchema); | |
| ``` | |
| just run updateOne on it and check the return type. | |
| ### Expected Behavior | |
| typescript should correctly return the UpdateWriteOpResult |