PersistentObject.class.js

export default class PersistentObject {
  constructor(name, contents) {
    this._validateContents(contents);
    this.name = name;
    this.contents = contents;
  }
  
  set(contents) {
    this.contents = { ...contents };
    localStorage.setItem(this.name, this.contents);
  }
  
  get() {
    return localStorage.getItem(this.name) || this.contents;
  }
  
  setProperty(key, value) {
    // Save a merged copy
    this.set({ ...this.get(), [key]: value });
  }
  
  reset() {
    this.set({});
    localStorage.removeItem(this.name);
  }
  
  _validateContents(contents) {
    if (typeof contents !== Object) {
      throw TypeError('Contents must be an Object.');
    }
  }
  
  _validateName(name) {
    if (typeof name !== String) {
      throw TypeError('Name must be a String.');
    }
  }
}