text: /**
   * Copyright 2013-2015, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under the BSD-style license found in the
   * LICENSE file in the root directory of this source tree. An additional grant
   * of patent rights can be found in the PATENTS file in the same directory.
   *
   * @typechecks static-only
   * @providesModule cloneWithProps
   */
  
  'use strict';
  
  var ReactElement = require('ReactElement');
  var ReactPropTransferer = require('ReactPropTransferer');
  
  var keyOf = require('keyOf');
  var warning = require('warning');
  
  var CHILDREN_PROP = keyOf({children: null});
  
  /**
   * Sometimes you want to change the props of a child passed to you. Usually
   * this is to add a CSS class.
   *
   * @param {ReactElement} child child element you'd like to clone
   * @param {object} props props you'd like to modify. className and style will be
   * merged automatically.
   * @return {ReactElement} a clone of child with props merged in.
   */
  function cloneWithProps(child, props) {
    if (__DEV__) {
      warning(
        !child.ref,
        'You are calling cloneWithProps() on a child with a ref. This is ' +
        'dangerous because you\'re creating a new child which will not be ' +
        'added as a ref to its parent.'
      );
    }
  
    var newProps = ReactPropTransferer.mergeProps(props, child.props);
  
    // Use `child.props.children` if it is provided.
    if (!newProps.hasOwnProperty(CHILDREN_PROP) &&
        child.props.hasOwnProperty(CHILDREN_PROP)) {
      newProps.children = child.props.children;
    }
  
    // The current API doesn't retain _owner, which is why this
    // doesn't use ReactElement.cloneAndReplaceProps.
    return ReactElement.createElement(child.type, newProps);
  }
  
  module.exports = cloneWithProps;
  