react-bootstrap/src/utils/Object.assign.js

Bootstrap 3 components build with React

/**
 * Copyright 2014, Facebook, Inc.
 * All rights reserved.
 *
 * This file contains an unmodified version of:
 * https://github.com/facebook/react/blob/v0.12.0/src/vendor/stubs/Object.assign.js
 *
 * This source code is licensed under the BSD-style license found here:
 * https://github.com/facebook/react/blob/v0.12.0/LICENSE
 * An additional grant of patent rights can be found here:
 * https://github.com/facebook/react/blob/v0.12.0/PATENTS
 */

// https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.assign

function assign(target, sources) {
  if (target == null) {
    throw new TypeError('Object.assign target cannot be null or undefined');
  }

  let to = Object(target);
  let hasOwnProperty = Object.prototype.hasOwnProperty;

  for (let nextIndex = 1; nextIndex < arguments.length; nextIndex++) {
    let nextSource = arguments[nextIndex];
    if (nextSource == null) {
      continue;
    }

    let from = Object(nextSource);

    // We don't currently support accessors nor proxies. Therefore this
    // copy cannot throw. If we ever supported this then we must handle
    // exceptions and side-effects. We don't support symbols so they won't
    // be transferred.

    for (let key in from) {
      if (hasOwnProperty.call(from, key)) {
        to[key] = from[key];
      }
    }
  }

  return to;
}

export default assign;