toCurrency.js

/*
 * https://locutus.io/php/strings/number_format/
 * _number_format(number:number, decimals:number, decPoint:string, thousandsSep:string):string
 * Returns a string which represents the number formatted
 */

const _number_format = (number, decimals, decPoint, thousandsSep) => {
  // eslint-disable-line camelcase
  number = (number + '').replace(/[^0-9+\-Ee.]/g, '');
  var n = !isFinite(+number) ? 0 : +number;
  var prec = !isFinite(+decimals) ? 0 : Math.abs(decimals);
  var sep = typeof thousandsSep === 'undefined' ? ',' : thousandsSep;
  var dec = typeof decPoint === 'undefined' ? '.' : decPoint;
  var s = '';

  var toFixedFix = function(n, prec) {
    if (('' + n).indexOf('e') === -1) {
      return +(Math.round(n + 'e+' + prec) + 'e-' + prec);
    } else {
      var arr = ('' + n).split('e');
      var sig = '';
      if (+arr[1] + prec > 0) {
        sig = '+';
      }
      return (+(Math.round(+arr[0] + 'e' + sig + (+arr[1] + prec)) + 'e-' + prec)).toFixed(prec);
    }
  };

  // @todo: for IE parseFloat(0.55).toFixed(0) = 0;
  s = (prec ? toFixedFix(n, prec).toString() : '' + Math.round(n)).split('.');
  if (s[0].length > 3) {
    s[0] = s[0].replace(/\B(?=(?:\d{3})+(?!\d))/g, sep);
  }
  if ((s[1] || '').length < prec) {
    s[1] = s[1] || '';
    s[1] += new Array(prec - s[1].length + 1).join('0');
  }

  return s.join(dec);
};

const defaultLocaleOptions = {
  decimals: 2,
  decimalSep: ',',
  thousandsSep: '.',
  currencySymbol: '€',
};

/*
 * toCurrency(num:number, localeOptions):string
 * Returns a currency formatted number
 */
const toCurrency = (num, localeOptions = defaultLocaleOptions) => {
  const {decimals, decimalSep, thousandsSep, currencySymbol} = localeOptions;
  return `${_number_format(num, decimals, decimalSep, thousandsSep)} ${currencySymbol}`;
};

export default toCurrency;