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deepDiffer.js
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deepDiffer.js
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/**
* 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 deepDiffer
* @flow
*/
'use strict';
/*
* @returns {bool} true if different, false if equal
*/
var deepDiffer = function(one: any, two: any): bool {
if (one === two) {
// Short circuit on identical object references instead of traversing them.
return false;
}
if ((typeof one === 'function') && (typeof two === 'function')) {
// We consider all functions equal
return false;
}
if ((typeof one !== 'object') || (one === null)) {
// Primitives can be directly compared
return one !== two;
}
if ((typeof two !== 'object') || (two === null)) {
// We know they are different because the previous case would have triggered
// otherwise.
return true;
}
if (one.constructor !== two.constructor) {
return true;
}
for (var key in one) {
if (deepDiffer(one[key], two[key])) {
return true;
}
}
for (var twoKey in two) {
// The only case we haven't checked yet is keys that are in two but aren't
// in one, which means they are different.
if (one[twoKey] === undefined && two[twoKey] !== undefined) {
return true;
}
}
return false;
};
module.exports = deepDiffer;