Meteor EasySearch case insensitive substring search query

gistfile1.txt

    query: function(searchString) {
      var field, selector, stringSelector;
      selector = {};
      field = this.field;
      stringSelector = {
        '$regex': '.*' + searchString + '.*',
        '$options': 'i'
      };
      if (_.isString(field)) {
        selector[field] = stringSelector;
        return selector;
      }
      if (this.convertNumbers && parseInt(searchString, 10) === searchString) {
        searchString = parseInt(searchString, 10);
      }
      selector['$or'] = [];
      _.each(field, function(fieldString) {
        var orSelector;
        orSelector = {};
        if (_.isString(searchString)) {
          orSelector[fieldString] = stringSelector;
        } else if (_.isNumber(searchString)) {
          orSelector[fieldString] = searchString;
        }
        return selector['$or'].push(orSelector);
      });
      return selector;
    }