secretstorage.js

// stolen from discord client
const ls = window.localStorage;
try {
  delete window.localStorage;
} catch(o) {}

function localStorageTest() {
  const test = 'test';
  try {
    ls.setItem(test, test);
    ls.removeItem(test);
    return true;
  } catch (e) {
    return false;
  }
}

class LocalStorage {
  get(key) {
    let value = ls.getItem(key);
    if (value !== null) {
      try {
        value = JSON.parse(value);
      } catch (e) {}
    }
    return value;
  }

  has(key) {
    return this.get(key) !== null;
  }

  set(key, value) {
    ls.setItem(key, JSON.stringify(value));
  }

  remove(key) {
    ls.removeItem(key);
  }

  clear() {
    ls.clear();
  }
}

class ObjectStorage {
  constructor() {
    this.storage = {};
  }

  get(key) {
    return this.storage[key];
  }

  has(key) {
    return this.get(key) !== null;
  }

  set(key, value) {
    this.storage[key] = value;
  }

  remove(key) {
    delete this.storage[key];
  }

  clear() {
    this.storage = {};
  }
}

const implementation = localStorageTest() ? new LocalStorage : new ObjectStorage;