49 lines
1.3 KiB
Plaintext
49 lines
1.3 KiB
Plaintext
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/**
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* Copyright (c) 2013-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @providesModule mapObject
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*/
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'use strict';
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var hasOwnProperty = Object.prototype.hasOwnProperty;
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/**
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* Executes the provided `callback` once for each enumerable own property in the
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* object and constructs a new object from the results. The `callback` is
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* invoked with three arguments:
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*
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* - the property value
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* - the property name
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* - the object being traversed
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*
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* Properties that are added after the call to `mapObject` will not be visited
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* by `callback`. If the values of existing properties are changed, the value
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* passed to `callback` will be the value at the time `mapObject` visits them.
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* Properties that are deleted before being visited are not visited.
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*
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* @grep function objectMap()
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* @grep function objMap()
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*
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* @param {?object} object
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* @param {function} callback
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* @param {*} context
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* @return {?object}
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*/
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function mapObject(object, callback, context) {
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if (!object) {
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return null;
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}
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var result = {};
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for (var name in object) {
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if (hasOwnProperty.call(object, name)) {
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result[name] = callback.call(context, object[name], name, object);
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}
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}
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return result;
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}
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module.exports = mapObject;
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