An Amplify.Storage class for Chrome extensions

background-storage.js

/* global chrome */


const MEMORY_KEY_PREFIX = '@BackgroundStorage:';
let dataMemory = {};

export default class BackgroundStorage {

  static syncPromise = null;

  static setItem(key, value) {
    chrome.runtime.sendMessage({action: 'store', subAction: 'setItem', key: MEMORY_KEY_PREFIX + key, value});
    dataMemory[key] = value;
    return dataMemory[key];
  };

  static getItem(key) {
    return Object.prototype.hasOwnProperty.call(dataMemory, key) ? dataMemory[key] : undefined;
  };

  static removeItem(key) {
    chrome.runtime.sendMessage({action: 'store', subAction: 'removeItem', key: MEMORY_KEY_PREFIX + key});
    return delete dataMemory[key];
  }

  static clear() {
    chrome.runtime.sendMessage({action: 'store', subAction: 'clear'});
    dataMemory = {};
    return dataMemory;
  }

  static sync() {
    if (!BackgroundStorage.syncPromise) {
      BackgroundStorage.syncPromise = new Promise((res, rej) => {
        chrome.runtime.sendMessage({action: 'store', subAction: 'getAllKeys'}, messageResponse => {
          const [response, error] = messageResponse;
          if (error) rej(error);
          const memoryKeys = response.filter((key) => key.startsWith(MEMORY_KEY_PREFIX));
          chrome.runtime.sendMessage({action: 'store', subAction: 'multiGet', keys: memoryKeys}, messageResponse => {
            const [response, error] = messageResponse;
            if (error) rej(error);
            Object.keys(response).forEach(key => {
              const memoryKey = key.replace(MEMORY_KEY_PREFIX, '');
              dataMemory[memoryKey] = response[key];
            });
            res();
          });
        });
      });
    }
    return BackgroundStorage.syncPromise;
  }

}