deprecated.js

/**
 * Copyright 2013-2014, 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.
 *
 * @providesModule deprecated
 */

var assign = require('Object.assign');
var warning = require('warning');

/**
 * This will log a single deprecation notice per function and forward the call
 * on to the new API.
 *
 * @param {string} namespace The namespace of the call, eg 'React'
 * @param {string} oldName The old function name, eg 'renderComponent'
 * @param {string} newName The new function name, eg 'render'
 * @param {*} ctx The context this forwarded call should run in
 * @param {function} fn The function to forward on to
 * @return {*} Will be the value as returned from `fn`
 */
function deprecated(namespace, oldName, newName, ctx, fn) {
  var warned = false;
  if (__DEV__) {
    var newFn = function() {
      warning(
        warned,
        `${namespace}.${oldName} will be deprecated in a future version. ` +
        `Use ${namespace}.${newName} instead.`
      );
      warned = true;
      return fn.apply(ctx, arguments);
    };
    newFn.displayName = `${namespace}_${oldName}`;
    // We need to make sure all properties of the original fn are copied over.
    // In particular, this is needed to support PropTypes
    return assign(newFn, fn);
  }

  return fn;
}

module.exports = deprecated;