RXJS + defineProperty

rxjs_experiment.ts

import { BehaviorSubject } from "rxjs";

const user$ = new BehaviorSubject<User>(null);

const state: State = {
  user: null
};

Reflect.defineProperty(state, "user", {
  get: () => {
    return deepFreeze(user$.value);
  }
});

user$.next({ id: "1", name: "ezeki", info: { test: 1 }, items: [{test2: 2}] });

console.log(state.user);

state.user.items[0].test2 = 3;


// helpers
function deepFreeze(object) {
  // Retrieve the property names defined on object
  var propNames = Object.getOwnPropertyNames(object);

  // Freeze properties before freezing self
  
  for (let name of propNames) {
    let value = object[name];

    if(value && typeof value === "object") { 
      deepFreeze(value);
    }
  }

  return Object.freeze(object);
}

// types
interface State {
  user: User | null;
}

interface User {
  id: string;
  name: string;
  info: {
    test: number;
  };
  items: {
    test2: number;
  }[]
}