The `ModelObject<this>` type lose properties.

type NonFunctionPropertyNames<T> = { [K in keyof T]: T[K] extends Function ? never : K }[keyof T];

type ModelObject<T extends object> = {
  [K in Exclude<NonFunctionPropertyNames<T>, 'model'>]: T[K];
};

class User {
  id!: number;
  name!: string;
  avatar!: string;

  toJson () {
    const rs: ModelObject<this> = 0 as any;

    return rs;
  }

  getName () {
    const json = this.toJson();

    return json.name; // Property 'name' does not exist on type 'ModelObject<this>'.
  }
}

type UserJson = NonFunctionPropertyNames<User>; // output type UserJson = "id" | "name" | "avatar"

[cerino-ligutom]

Experiencing this.

“typescript”: “4.1.5” “objection”: “2.2.14”

[koskimas]

Ok. I think this is a bug introduced by typescript 4. Objection’s tests still use 3.9.something. Typescrip 4 probably changed how the this type is handled in some cases.