localStorage utility for typescript - keep track of types! 😀

localStorageUtility.ts

// store objects and keep track of types with Window.localStorage 
// (https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage)

interface Bar {}

export enum CacheKey {
  Foo = 'Foo'
}

interface CacheValues {
  [CacheKey.Foo]: Bar;
}

interface CacheUtil {
  set: <T extends CacheKey>(key: T, object: CacheValues[T]) => void;
  get: <T extends CacheKey>(key: T) => CacheValues[T];
  remove: (key: CacheKey) => void;
  removeAll: () => void;
}

export const cacheUtil: CacheUtil = {
  set: (key, object) => {
    localStorage.setItem(key, JSON.stringify(object));
  },
  get: key => JSON.parse(localStorage.getItem(key) ?? {}),
  remove: (key) => localStorage.removeItem(key),
  removeAll: () => localStorage.clear(),
};

// check out the following StackOverflow link for a collection of other useful localStorage functions
// https://stackoverflow.com/questions/34245593/html5-localstorage-useful-functions-javascript-typescript 

why would you use ?? in line 25? JSON.parse('') will throw an exception

JSON.parse expects a string. {} is not a string. You need to use quotes

JSON.parse(localStorage.getItem(key) ?? "{}")
thank you for this!