GT2/GT2-iOS/node_modules/fbjs/lib/keyMirrorRecursive.js.flow

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/**
* Copyright (c) 2013-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @providesModule keyMirrorRecursive
* @flow weak
* @typechecks
*/
'use strict';
var invariant = require('./invariant');
/**
* Constructs an enumeration with keys equal to their value. If the value is an
* object, the method is run recursively, including the parent key as a suffix.
* An optional prefix can be provided that will be prepended to each value.
*
* For example:
*
* var ACTIONS = keyMirror({FOO: null, BAR: { BAZ: null, BOZ: null }}});
* ACTIONS.BAR.BAZ = 'BAR.BAZ';
*
* Input: {key1: null, key2: { nested1: null, nested2: null }}}
* Output: {key1: key1, key2: { nested1: nested1, nested2: nested2 }}}
*
* var CONSTANTS = keyMirror({FOO: {BAR: null}}, 'NameSpace');
* console.log(CONSTANTS.FOO.BAR); // NameSpace.FOO.BAR
*/
function keyMirrorRecursive<T>(obj: T, prefix?: ?string): T {
return keyMirrorRecursiveInternal(obj, prefix);
}
function keyMirrorRecursiveInternal(
/*object*/obj,
/*?string*/prefix) /*object*/{
var ret = {};
var key;
invariant(isObject(obj), 'keyMirrorRecursive(...): Argument must be an object.');
for (key in obj) {
if (!obj.hasOwnProperty(key)) {
continue;
}
var val = obj[key];
var newPrefix = prefix ? prefix + '.' + key : key;
if (isObject(val)) {
val = keyMirrorRecursiveInternal(val, newPrefix);
} else {
val = newPrefix;
}
ret[key] = val;
}
return ret;
}
function isObject(obj) /*boolean*/{
return obj instanceof Object && !Array.isArray(obj);
}
module.exports = keyMirrorRecursive;