function compareAscending(a, b) {
    return baseCompareAscending(a.criteria, b.criteria) || a.index - b.index;
  }
Used by `sortBy` to compare transformed elements of a collection and stable
sort them in ascending order.

@private
@param {Object} a The object to compare to `b`.
@param {Object} b The object to compare to `a`.
@returns {number} Returns the sort order indicator for `a`.