chunkify.js

/**
 * Turn an array into chunks
 *
 * @param {Array} arr - Array that should be chunked
 * @param {number} size - Chunk size
 * @returns {Array} Array of Arrays where each array has at max `size` elements
 */
const chunkify = (arr, size) =>
  arr.reduce(
    (acc, cur) =>
      acc.slice(-1)[0].length < size
        ? [...acc.slice(0, -1), acc.slice(-1)[0].concat([cur])]
        : [...acc, [cur]],
    [[]]
  );