text: 'use strict';
  
  exports.type = 'perItem';
  
  exports.active = false;
  
  exports.description = 'removes viewBox attribute when possible (disabled by default)';
  
  var regViewBox = /^0\s0\s([\-+]?\d*\.?\d+([eE][\-+]?\d+)?)\s([\-+]?\d*\.?\d+([eE][\-+]?\d+)?)$/,
      viewBoxElems = ['svg', 'pattern'];
  
  /**
   * Remove viewBox attr which coincides with a width/height box.
   *
   * @see http://www.w3.org/TR/SVG/coords.html#ViewBoxAttribute
   *
   * @example
   * <svg width="100" height="50" viewBox="0 0 100 50">
   *             ⬇
   * <svg width="100" height="50">
   *
   * @param {Object} item current iteration item
   * @return {Boolean} if false, item will be filtered out
   *
   * @author Kir Belevich
   */
  exports.fn = function(item) {
  
      if (
          item.isElem(viewBoxElems) &&
          item.hasAttr('viewBox') &&
          item.hasAttr('width') &&
          item.hasAttr('height')
      ) {
  
          var match = item.attr('viewBox').value.match(regViewBox);
  
          if (match) {
              if (
                  item.attr('width').value === match[1] &&
                  item.attr('height').value === match[3]
              ) {
                  item.removeAttr('viewBox');
              }
          }
  
      }
  
  };
  