jasonmerino/react-native-simple-store

/**
 * @overview A minimalistic wrapper around React Native's AsyncStorage.
 * @license MIT
 */
import merge from 'lodash.merge';
import AsyncStorage from '@react-native-community/async-storage';

const deviceStorage = {
    /**
     * Get a one or more value for a key or array of keys from AsyncStorage
     * @param {String|Array} key A key or array of keys
     * @return {Promise}
     */
    get(key) {
        if(!Array.isArray(key)) {
            return AsyncStorage.getItem(key).then(value => {
                return JSON.parse(value);
            });
        } else {
            return AsyncStorage.multiGet(key).then(values => {
                return values.map(value => {
                    return JSON.parse(value[1]);
                });
            });
        }
    },

    /**
     * Save a key value pair or a series of key value pairs to AsyncStorage.
     * @param  {String|Array} key The key or an array of key/value pairs
     * @param  {Any} value The value to save
     * @return {Promise}
     */
    save(key, value) {
        if(!Array.isArray(key)) {
            return AsyncStorage.setItem(key, JSON.stringify(value));
        } else {
            var pairs = key.map(function(pair) {
                return [pair[0], JSON.stringify(pair[1])];
            });
            return AsyncStorage.multiSet(pairs);
        }
    },

    /**
     * Updates the value in the store for a given key in AsyncStorage. If the value is a string it will be replaced. If the value is an object it will be deep merged.
     * @param  {String} key The key
     * @param  {Value} value The value to update with
     * @return {Promise}
     */
    update(key, value) {
        return deviceStorage.get(key).then(item => {
            value = typeof value === 'string' ? value : merge({}, item, value);
            return AsyncStorage.setItem(key, JSON.stringify(value));
        });
    },

    /**
     * Delete the value for a given key in AsyncStorage.
     * @param  {String|Array} key The key or an array of keys to be deleted
     * @return {Promise}
     */
    delete(key) {
        if (Array.isArray(key)) {
            return AsyncStorage.multiRemove(key);
        } else {
            return AsyncStorage.removeItem(key);
        }
    },

    /**
     * Get all keys in AsyncStorage.
     * @return {Promise} A promise which when it resolves gets passed the saved keys in AsyncStorage.
     */
    keys() {
        return AsyncStorage.getAllKeys();
    },

    /**
     * Push a value onto an array stored in AsyncStorage by key or create a new array in AsyncStorage for a key if it's not yet defined.
     * @param {String} key They key
     * @param {Any} value The value to push onto the array
     * @return {Promise}
     */
    push(key, value) {
        return deviceStorage.get(key).then((currentValue) => {
            if (currentValue === null) {
                // if there is no current value populate it with the new value
                return deviceStorage.save(key, [value]);
            }
            if (Array.isArray(currentValue)) {
                return deviceStorage.save(key, [...currentValue, value]);
            }
            throw new Error(`Existing value for key "${key}" must be of type null or Array, received ${typeof currentValue}.`);
        });
    },
};

module.exports = deviceStorage;