71 lines
2.3 KiB
JavaScript
71 lines
2.3 KiB
JavaScript
/**
|
|
* Copyright (c) 2015-present, 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 Object.es6
|
|
* @polyfill
|
|
* @nolint
|
|
*/
|
|
|
|
/* eslint-disable strict */
|
|
|
|
// WARNING: This is an optimized version that fails on hasOwnProperty checks
|
|
// and non objects. It's not spec-compliant. It's a perf optimization.
|
|
// This is only needed for iOS 8 and current Android JSC.
|
|
|
|
Object.assign = function(target, sources) {
|
|
if (__DEV__) {
|
|
if (target == null) {
|
|
throw new TypeError('Object.assign target cannot be null or undefined');
|
|
}
|
|
if (typeof target !== 'object' && typeof target !== 'function') {
|
|
throw new TypeError(
|
|
'In this environment the target of assign MUST be an object. ' +
|
|
'This error is a performance optimization and not spec compliant.'
|
|
);
|
|
}
|
|
}
|
|
|
|
for (var nextIndex = 1; nextIndex < arguments.length; nextIndex++) {
|
|
var nextSource = arguments[nextIndex];
|
|
if (nextSource == null) {
|
|
continue;
|
|
}
|
|
|
|
if (__DEV__) {
|
|
if (typeof nextSource !== 'object' &&
|
|
typeof nextSource !== 'function') {
|
|
throw new TypeError(
|
|
'In this environment the sources for assign MUST be an object. ' +
|
|
'This error is a performance optimization and not spec compliant.'
|
|
);
|
|
}
|
|
}
|
|
|
|
// 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.
|
|
|
|
for (var key in nextSource) {
|
|
if (__DEV__) {
|
|
var hasOwnProperty = Object.prototype.hasOwnProperty;
|
|
if (!hasOwnProperty.call(nextSource, key)) {
|
|
throw new TypeError(
|
|
'One of the sources for assign has an enumerable key on the ' +
|
|
'prototype chain. Are you trying to assign a prototype property? ' +
|
|
'We don\'t allow it, as this is an edge case that we do not support. ' +
|
|
'This error is a performance optimization and not spec compliant.'
|
|
);
|
|
}
|
|
}
|
|
target[key] = nextSource[key];
|
|
}
|
|
}
|
|
|
|
return target;
|
|
};
|