Lodash: merge property paths given as strings or arrays into one

mergePaths.js

/**
 * @param {...(string|Array)} paths
 *
 * @example
 * > mergePaths('a.b.c', 'd');
 * // ['a', 'b', 'c', 'd']
 *
 * > mergePaths('a.b.c', ['d']);
 * // ['a', 'b', 'c', 'd']
 *
 * > mergePaths(['a', 'b', 'c'], ['d']);
 * // ['a', 'b', 'c', 'd']
 *
 * > mergePaths(['a', 'b', 'c'], 'd');
 * // ['a', 'b', 'c', 'd']
 *
 * @returns {Array}
 */
const mergePaths = (...paths) => _.flatMap(paths, _.toPath);