src/array/flatten.js
/**
* Flattens `array` a single level deep.
*
* @param {Array} array The array to flatten.
* @returns {Array} Returns the new flattened array.
* @example
*
* flatten([1, [2, [3]]])
* // => [1, 2, [3]]
*/
const flatten = array => [].concat(...array);
export default flatten;