190 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			190 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| 'use strict';
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| 
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| Object.defineProperty(exports, "__esModule", {
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|     value: true
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| });
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| 
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| var _map = require('./map.js');
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| 
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| var _map2 = _interopRequireDefault(_map);
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| 
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| var _wrapAsync = require('./internal/wrapAsync.js');
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| 
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| var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
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| 
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| var _awaitify = require('./internal/awaitify.js');
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| 
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| var _awaitify2 = _interopRequireDefault(_awaitify);
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| 
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| function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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| 
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| /**
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|  * Sorts a list by the results of running each `coll` value through an async
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|  * `iteratee`.
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|  *
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|  * @name sortBy
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|  * @static
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|  * @memberOf module:Collections
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|  * @method
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|  * @category Collection
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|  * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
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|  * @param {AsyncFunction} iteratee - An async function to apply to each item in
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|  * `coll`.
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|  * The iteratee should complete with a value to use as the sort criteria as
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|  * its `result`.
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|  * Invoked with (item, callback).
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|  * @param {Function} callback - A callback which is called after all the
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|  * `iteratee` functions have finished, or an error occurs. Results is the items
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|  * from the original `coll` sorted by the values returned by the `iteratee`
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|  * calls. Invoked with (err, results).
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|  * @returns {Promise} a promise, if no callback passed
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|  * @example
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|  *
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|  * // bigfile.txt is a file that is 251100 bytes in size
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|  * // mediumfile.txt is a file that is 11000 bytes in size
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|  * // smallfile.txt is a file that is 121 bytes in size
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|  *
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|  * // asynchronous function that returns the file size in bytes
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|  * function getFileSizeInBytes(file, callback) {
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|  *     fs.stat(file, function(err, stat) {
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|  *         if (err) {
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|  *             return callback(err);
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|  *         }
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|  *         callback(null, stat.size);
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|  *     });
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|  * }
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|  *
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|  * // Using callbacks
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|  * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes,
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|  *     function(err, results) {
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|  *         if (err) {
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|  *             console.log(err);
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|  *         } else {
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|  *             console.log(results);
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|  *             // results is now the original array of files sorted by
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|  *             // file size (ascending by default), e.g.
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|  *             // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
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|  *         }
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|  *     }
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|  * );
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|  *
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|  * // By modifying the callback parameter the
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|  * // sorting order can be influenced:
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|  *
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|  * // ascending order
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|  * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], function(file, callback) {
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|  *     getFileSizeInBytes(file, function(getFileSizeErr, fileSize) {
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|  *         if (getFileSizeErr) return callback(getFileSizeErr);
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|  *         callback(null, fileSize);
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|  *     });
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|  * }, function(err, results) {
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|  *         if (err) {
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|  *             console.log(err);
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|  *         } else {
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|  *             console.log(results);
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|  *             // results is now the original array of files sorted by
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|  *             // file size (ascending by default), e.g.
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|  *             // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
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|  *         }
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|  *     }
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|  * );
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|  *
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|  * // descending order
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|  * async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], function(file, callback) {
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|  *     getFileSizeInBytes(file, function(getFileSizeErr, fileSize) {
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|  *         if (getFileSizeErr) {
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|  *             return callback(getFileSizeErr);
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|  *         }
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|  *         callback(null, fileSize * -1);
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|  *     });
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|  * }, function(err, results) {
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|  *         if (err) {
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|  *             console.log(err);
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|  *         } else {
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|  *             console.log(results);
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|  *             // results is now the original array of files sorted by
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|  *             // file size (ascending by default), e.g.
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|  *             // [ 'bigfile.txt', 'mediumfile.txt', 'smallfile.txt']
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|  *         }
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|  *     }
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|  * );
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|  *
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|  * // Error handling
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|  * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes,
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|  *     function(err, results) {
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|  *         if (err) {
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|  *             console.log(err);
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|  *             // [ Error: ENOENT: no such file or directory ]
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|  *         } else {
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|  *             console.log(results);
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|  *         }
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|  *     }
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|  * );
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|  *
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|  * // Using Promises
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|  * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes)
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|  * .then( results => {
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|  *     console.log(results);
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|  *     // results is now the original array of files sorted by
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|  *     // file size (ascending by default), e.g.
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|  *     // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
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|  * }).catch( err => {
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|  *     console.log(err);
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|  * });
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|  *
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|  * // Error handling
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|  * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes)
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|  * .then( results => {
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|  *     console.log(results);
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|  * }).catch( err => {
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|  *     console.log(err);
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|  *     // [ Error: ENOENT: no such file or directory ]
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|  * });
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|  *
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|  * // Using async/await
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|  * (async () => {
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|  *     try {
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|  *         let results = await async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes);
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|  *         console.log(results);
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|  *         // results is now the original array of files sorted by
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|  *         // file size (ascending by default), e.g.
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|  *         // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
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|  *     }
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|  *     catch (err) {
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|  *         console.log(err);
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|  *     }
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|  * })();
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|  *
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|  * // Error handling
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|  * async () => {
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|  *     try {
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|  *         let results = await async.sortBy(['missingfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes);
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|  *         console.log(results);
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|  *     }
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|  *     catch (err) {
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|  *         console.log(err);
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|  *         // [ Error: ENOENT: no such file or directory ]
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|  *     }
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|  * }
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|  *
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|  */
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| function sortBy(coll, iteratee, callback) {
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|     var _iteratee = (0, _wrapAsync2.default)(iteratee);
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|     return (0, _map2.default)(coll, (x, iterCb) => {
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|         _iteratee(x, (err, criteria) => {
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|             if (err) return iterCb(err);
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|             iterCb(err, { value: x, criteria });
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|         });
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|     }, (err, results) => {
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|         if (err) return callback(err);
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|         callback(null, results.sort(comparator).map(v => v.value));
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|     });
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| 
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|     function comparator(left, right) {
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|         var a = left.criteria,
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|             b = right.criteria;
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|         return a < b ? -1 : a > b ? 1 : 0;
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|     }
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| }
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| exports.default = (0, _awaitify2.default)(sortBy, 3);
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| module.exports = exports.default; |