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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 isEmpty
* @flow
*/
'use strict';
/* eslint-disable fb-www/typeof-undefined */
/* eslint-disable no-unused-vars */
const invariant = require('./invariant');
/**
* Checks if a value is empty.
*/
function isEmpty(value: mixed): boolean {
if (Array.isArray(value)) {
return value.length === 0;
} else if (typeof value === 'object') {
if (value) {
invariant(!isIterable(value) || value.size === undefined, 'isEmpty() does not support iterable collections.');
for (const _ in value) {
return false;
}
}
return true;
} else {
return !value;
}
}
function isIterable(value: any): boolean {
if (typeof Symbol === 'undefined') {
return false;
}
return value[Symbol.iterator];
}
module.exports = isEmpty;
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