mirror of
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88 lines
2.5 KiB
JavaScript
88 lines
2.5 KiB
JavaScript
/**
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* lodash 3.0.0 (Custom Build) <https://lodash.com/>
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* Build: `lodash modern modularize exports="npm" -o ./`
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* Copyright 2012-2015 The Dojo Foundation <http://dojofoundation.org/>
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* Based on Underscore.js 1.7.0 <http://underscorejs.org/LICENSE>
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* Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
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* Available under MIT license <https://lodash.com/license>
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*/
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var isArguments = require('lodash.isarguments'),
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isArray = require('lodash.isarray'),
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isFunction = require('lodash.isfunction'),
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isString = require('lodash.isstring'),
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keys = require('lodash.keys');
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/**
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* Checks if `value` is object-like.
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*
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* @private
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
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*/
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function isObjectLike(value) {
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return (value && typeof value == 'object') || false;
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}
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/**
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* Used as the maximum length of an array-like value.
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* See the [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-number.max_safe_integer)
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* for more details.
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*/
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var MAX_SAFE_INTEGER = Math.pow(2, 53) - 1;
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/**
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* Checks if `value` is a valid array-like length.
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*
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* **Note:** This function is based on ES `ToLength`. See the
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* [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength)
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* for more details.
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*
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* @private
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* @param {*} value The value to check.
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* @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
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*/
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function isLength(value) {
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return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
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}
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/**
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* Checks if `value` is empty. A value is considered empty unless it is an
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* `arguments` object, array, string, or jQuery-like collection with a length
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* greater than `0` or an object with own enumerable properties.
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*
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* @static
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* @memberOf _
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* @category Lang
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* @param {Array|Object|string} value The value to inspect.
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* @returns {boolean} Returns `true` if `value` is empty, else `false`.
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* @example
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*
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* _.isEmpty(null);
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* // => true
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*
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* _.isEmpty(true);
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* // => true
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*
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* _.isEmpty(1);
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* // => true
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*
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* _.isEmpty([1, 2, 3]);
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* // => false
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*
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* _.isEmpty({ 'a': 1 });
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* // => false
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*/
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function isEmpty(value) {
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if (value == null) {
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return true;
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}
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var length = value.length;
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if (isLength(length) && (isArray(value) || isString(value) || isArguments(value) ||
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(isObjectLike(value) && isFunction(value.splice)))) {
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return !length;
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}
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return !keys(value).length;
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}
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module.exports = isEmpty;
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