const extension = require('extensionizer') const log = require('loglevel') /** * A wrapper around the extension's storage local API */ module.exports = class ExtensionStore { /** * @constructor */ constructor() { this.isSupported = !!(extension.storage.local) if (!this.isSupported) { log.error('Storage local API not available.') } } /** * Returns all of the keys currently saved * @return {Promise<*>} */ async get() { if (!this.isSupported) return undefined const result = await this._get() // extension.storage.local always returns an obj // if the object is empty, treat it as undefined if (isEmpty(result)) { return undefined } else { return result } } /** * Sets the key in local state * @param {object} state - The state to set * @return {Promise} */ async set(state) { return this._set(state) } /** * Returns all of the keys currently saved * @private * @return {object} the key-value map from local storage */ _get() { const local = extension.storage.local return new Promise((resolve, reject) => { local.get(null, (/** @type {any} */ result) => { const err = extension.runtime.lastError if (err) { reject(err) } else { resolve(result) } }) }) } /** * Sets the key in local state * @param {object} obj - The key to set * @return {Promise} * @private */ _set(obj) { const local = extension.storage.local return new Promise((resolve, reject) => { local.set(obj, () => { const err = extension.runtime.lastError if (err) { reject(err) } else { resolve() } }) }) } } /** * Returns whether or not the given object contains no keys * @param {object} obj - The object to check * @returns {boolean} */ function isEmpty(obj) { return Object.keys(obj).length === 0 }