Files
react-native/Libraries/Utilities/PolyfillFunctions.js
T
James Ide 0ee5f68929 Migrate "Libraries" from Haste to standard path-based requires (sans vendor & renderers) (#24749)
Summary:
This is the next step in moving RN towards standard path-based requires. All the requires in `Libraries` have been rewritten to use relative requires with a few exceptions, namely, `vendor` and `Renderer/oss` since those need to be changed upstream. This commit uses relative requires instead of `react-native/...` so that if Facebook were to stop syncing out certain folders and therefore remove code from the react-native package, internal code at Facebook would not need to change.

See the umbrella issue at https://github.com/facebook/react-native/issues/24316 for more detail.

[General] [Changed] - Migrate "Libraries" from Haste to standard path-based requires
Pull Request resolved: https://github.com/facebook/react-native/pull/24749

Differential Revision: D15258017

Pulled By: cpojer

fbshipit-source-id: a1f480ea36c05c659b6f37c8f02f6f9216d5a323
2019-05-08 08:48:59 -07:00

57 lines
1.7 KiB
JavaScript

/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
'use strict';
const defineLazyObjectProperty = require('./defineLazyObjectProperty');
/**
* Sets an object's property. If a property with the same name exists, this will
* replace it but maintain its descriptor configuration. The property will be
* replaced with a lazy getter.
*
* In DEV mode the original property value will be preserved as `original[PropertyName]`
* so that, if necessary, it can be restored. For example, if you want to route
* network requests through DevTools (to trace them):
*
* global.XMLHttpRequest = global.originalXMLHttpRequest;
*
* @see https://github.com/facebook/react-native/issues/934
*/
function polyfillObjectProperty<T>(
object: Object,
name: string,
getValue: () => T,
): void {
const descriptor = Object.getOwnPropertyDescriptor(object, name);
if (__DEV__ && descriptor) {
const backupName = `original${name[0].toUpperCase()}${name.substr(1)}`;
Object.defineProperty(object, backupName, descriptor);
}
const {enumerable, writable, configurable} = descriptor || {};
if (descriptor && !configurable) {
console.error('Failed to set polyfill. ' + name + ' is not configurable.');
return;
}
defineLazyObjectProperty(object, name, {
get: getValue,
enumerable: enumerable !== false,
writable: writable !== false,
});
}
function polyfillGlobal<T>(name: string, getValue: () => T): void {
polyfillObjectProperty(global, name, getValue);
}
module.exports = {polyfillObjectProperty, polyfillGlobal};