isException = function (node, next, previous) {
  if (node.is('space')) {
    if (next && next.is('combinator') || next.is('parentSelector')) {
      return true;
    }

    if (previous && previous.is('combinator') || previous.is('parentSelector')) {
      return true;
    }
  }

  return false;
}
Check if it's an exception (combinator or a parent selector before or after a space)

@param {Object} node - The node to check
@param {Object} next - The next node
@param {Object} previous - The previous node
@returns {Boolean} True if exception