'use strict';

/*!
 * ignore
 */

module.exports = function(schema) {
  // ensure the documents receive an id getter unless disabled
  var autoIdGetter = !schema.paths['id'] &&
      (!schema.options.noVirtualId && schema.options.id);
  if (autoIdGetter) {
    schema.virtual('id').get(idGetter);
  }
};

/*!
 * Returns this documents _id cast to a string.
 */

function idGetter() {
  if (this._id != null) {
    return String(this._id);
  }

  return null;
}