Using the make(auto)Observable api to make an already created instance of a class reactive

[Alexandreee100]

Hello, I want to create a domain model separated from the reactive library, and after it is created, I want to make it reactive. As far as I know, the MobX documentation recommends using make(auto)observable inside the class constructor, but it doesn’t prohibit using this API on an already created object (including non-plain objects with a prototype different from Object). What other ways are there to make a class instance reactive from the outside, apart from make(auto)observable? And is using make(auto)observable the normal way to achieve my goal?

I mean this:

class Parent {
  public name = 'Jon';
  public age = 20;

  public get full() {
    return `${this.name}: ${this.age}`;
  }

  public setName(value: string) {
    this.name = value;
  }
}

class Child extends Parent {
    public city = "New York"

    public setCity(value: string) {
        this.city = value;
    }
}


const instance = new Child();
const obs = makeObservable<Child>(instance, {
    city: true,
    name: true,
    age: true,
    full: true,
    setCity: true,
    setName: true
})