FilterQuery Typing fails for generic type about mongoose HOT 4 CLOSED

Error comes from v8.2.3.
v8.2.2 doesn't had this issue.

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related to #14462

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Looks like OP's script fails to compile with TypeScript 5.4.3:

$ ./node_modules/.bin/tsc --strict gh-14459.ts 
gh-14459.ts:4:23 - error TS2769: No overload matches this call.
  Overload 1 of 5, '(filter: FilterQuery<ModelType>, projection?: ProjectionType<ModelType> | null | undefined, options?: QueryOptions<ModelType> | null | undefined): Query<...>', gave the following error.
    Argument of type '{ _id: string | Types.ObjectId; }' is not assignable to parameter of type 'FilterQuery<ModelType>'.

I think this is just a limitation of TypeScript, because { _id: never } does satisfy extends {_id: Types.ObjectId | string}. For example, the following doesn't cause any errors with using { _id: never }:

import { Model, Types, model, Schema } from "mongoose";

function findById<ModelType extends {_id: Types.ObjectId | string}>(model: Model<ModelType>, _id: Types.ObjectId | string){
    return model.find({_id: _id})
}

type ModelType = { _id: never };
const TestModel = model<ModelType>('test', new Schema());

findById<ModelType>(TestModel, 'foo');

We will take a quick look to see if there's some way we can work around this weird never case

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I took a look but there's nothing we can do other than 1) make FilterQuery<T> = any, or 2) require as FilterQuery in OP's case as follows:

import { Model, Types, model, Schema, FilterQuery } from "mongoose";

function findById<ModelType extends {_id: Types.ObjectId | string}>(model: Model<ModelType>, _id: Types.ObjectId | string){
    return model.find({_id: _id} as FilterQuery<ModelType>);
}

This is suboptimal, but unfortunately a limitation of TypeScript. From this SO answer: "Never assign a concrete type to a generic type parameter, consider it as read-only!". That includes calling a function with arguments that rely on the generic type parameter.

Even if we make FilterQuery<T> = T, we get the following error '{ _id: string | Types.ObjectId; }' is assignable to the constraint of type 'ModelType', but 'ModelType' could be instantiated with a different subtype of constraint '{ _id: string | ObjectId; }'

Given that { _id: never } extends {_id: Types.ObjectId | string}, the TypeScript limitation makes sense, just quirky language design.

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