justDuIt.js

export const countSize = (node) => {
  reduce((size, element) => {
    if (element.type === 'file') {
      return (size + element.meta.size);
    }
    return size;
  }, node, 0);

export default (tree) => {
  const duIt = tree
    .children
    .map(element => [element.name, countSize(element)])
    .sort((a, b) => a[1] - b[1]);
};