helpers/sort.js

import { reach } from './reach.js';

/**
 * Sort collection asc by some field.
 *
 * @param  {String} field      Field to sort by.
 * @param  {Array}  collection Collection to sort.
 * @return {Array}             The sorted collection.
 */
const sortAsc = (field, collection) => {
  return collection.sort(function(a, b) {
    let s1 = reach(field, a);
    let s2 = reach(field, b);

    if (typeof s1 === 'string') {
      s1 = s1.toLowerCase();
    }

    if (typeof s2 === 'string') {
      s2 = s2.toLowerCase();
    }

    return naturalCompare(s1, s2);
  }.bind(this));
}

/**
 * Sort collection desc by some field.
 *
 * @param  {String} field      Field to sort by.
 * @param  {Array}  collection Collection to sort.
 * @return {Array}             The sorted collection.
 */
const sortDesc = (field, collection) => {
  return collection.sort(function(a, b) {
    let s1 = reach(field, a);
    let s2 = reach(field, b);

    if (typeof s1 === 'string') {
      s1 = s1.toLowerCase();
    }

    if (typeof s2 === 'string') {
      s2 = s2.toLowerCase();
    }

    return naturalCompare(s2, s1);
  }.bind(this));
}

/**
* Sort strings naturally.
*
* @version    1.4.0
* @date       2015-10-26
* @stability  3 - Stable
* @author     Lauri Rooden (https://github.com/litejs/natural-compare-lite)
* @license    MIT License
*
* @param  {String} a
* @param  {String} b
* @return {Number}   -1, 1 or 0.
*/
const naturalCompare = (a, b) => {
  let i;
  let codeA;
  let codeB = 1;
  let posA = 0;
  let posB = 0;
  const alphabet = String.alphabet;

  function getCode(str, pos, code) {
    if (code) {
      for (i = pos; code = getCode(str, i), code < 76 && code > 65;) ++i;
      return Number(str.slice(pos - 1, i));
    }
    code = alphabet && alphabet.indexOf(str.charAt(pos));
    return code > -1 ? code + 76 : ((code = str.charCodeAt(pos) || 0), code < 45 || code > 127) ? code
      : code < 46 ? 65               // -
      : code < 48 ? code - 1
      : code < 58 ? code + 18        // 0-9
      : code < 65 ? code - 11
      : code < 91 ? code + 11        // A-Z
      : code < 97 ? code - 37
      : code < 123 ? code + 5        // a-z
      : code - 63;
  }

  if ((a += '') != (b += '')) for (;codeB;) {
    codeA = getCode(a, posA++);
    codeB = getCode(b, posB++);

    if (codeA < 76 && codeB < 76 && codeA > 66 && codeB > 66) {
      codeA = getCode(a, posA, posA);
      codeB = getCode(b, posB, posA = i);
      posB = i;
    }

    if (codeA != codeB) return (codeA < codeB) ? -1 : 1;
  }
  return 0;
}

export { sortAsc, sortDesc, naturalCompare };