From 18efd30a263ec0d79a26a82cbd8c90c9f81056b7 Mon Sep 17 00:00:00 2001 From: Minteck Date: Mon, 28 Nov 2022 17:14:38 +0100 Subject: Open source --- node_modules/async/dist/async.js | 6059 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 6059 insertions(+) create mode 100644 node_modules/async/dist/async.js (limited to 'node_modules/async/dist/async.js') diff --git a/node_modules/async/dist/async.js b/node_modules/async/dist/async.js new file mode 100644 index 0000000..8d5e782 --- /dev/null +++ b/node_modules/async/dist/async.js @@ -0,0 +1,6059 @@ +(function (global, factory) { + typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) : + typeof define === 'function' && define.amd ? define(['exports'], factory) : + (factory((global.async = {}))); +}(this, (function (exports) { 'use strict'; + + /** + * Creates a continuation function with some arguments already applied. + * + * Useful as a shorthand when combined with other control flow functions. Any + * arguments passed to the returned function are added to the arguments + * originally passed to apply. + * + * @name apply + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {Function} fn - The function you want to eventually apply all + * arguments to. Invokes with (arguments...). + * @param {...*} arguments... - Any number of arguments to automatically apply + * when the continuation is called. + * @returns {Function} the partially-applied function + * @example + * + * // using apply + * async.parallel([ + * async.apply(fs.writeFile, 'testfile1', 'test1'), + * async.apply(fs.writeFile, 'testfile2', 'test2') + * ]); + * + * + * // the same process without using apply + * async.parallel([ + * function(callback) { + * fs.writeFile('testfile1', 'test1', callback); + * }, + * function(callback) { + * fs.writeFile('testfile2', 'test2', callback); + * } + * ]); + * + * // It's possible to pass any number of additional arguments when calling the + * // continuation: + * + * node> var fn = async.apply(sys.puts, 'one'); + * node> fn('two', 'three'); + * one + * two + * three + */ + function apply(fn, ...args) { + return (...callArgs) => fn(...args,...callArgs); + } + + function initialParams (fn) { + return function (...args/*, callback*/) { + var callback = args.pop(); + return fn.call(this, args, callback); + }; + } + + /* istanbul ignore file */ + + var hasQueueMicrotask = typeof queueMicrotask === 'function' && queueMicrotask; + var hasSetImmediate = typeof setImmediate === 'function' && setImmediate; + var hasNextTick = typeof process === 'object' && typeof process.nextTick === 'function'; + + function fallback(fn) { + setTimeout(fn, 0); + } + + function wrap(defer) { + return (fn, ...args) => defer(() => fn(...args)); + } + + var _defer; + + if (hasQueueMicrotask) { + _defer = queueMicrotask; + } else if (hasSetImmediate) { + _defer = setImmediate; + } else if (hasNextTick) { + _defer = process.nextTick; + } else { + _defer = fallback; + } + + var setImmediate$1 = wrap(_defer); + + /** + * Take a sync function and make it async, passing its return value to a + * callback. This is useful for plugging sync functions into a waterfall, + * series, or other async functions. Any arguments passed to the generated + * function will be passed to the wrapped function (except for the final + * callback argument). Errors thrown will be passed to the callback. + * + * If the function passed to `asyncify` returns a Promise, that promises's + * resolved/rejected state will be used to call the callback, rather than simply + * the synchronous return value. + * + * This also means you can asyncify ES2017 `async` functions. + * + * @name asyncify + * @static + * @memberOf module:Utils + * @method + * @alias wrapSync + * @category Util + * @param {Function} func - The synchronous function, or Promise-returning + * function to convert to an {@link AsyncFunction}. + * @returns {AsyncFunction} An asynchronous wrapper of the `func`. To be + * invoked with `(args..., callback)`. + * @example + * + * // passing a regular synchronous function + * async.waterfall([ + * async.apply(fs.readFile, filename, "utf8"), + * async.asyncify(JSON.parse), + * function (data, next) { + * // data is the result of parsing the text. + * // If there was a parsing error, it would have been caught. + * } + * ], callback); + * + * // passing a function returning a promise + * async.waterfall([ + * async.apply(fs.readFile, filename, "utf8"), + * async.asyncify(function (contents) { + * return db.model.create(contents); + * }), + * function (model, next) { + * // `model` is the instantiated model object. + * // If there was an error, this function would be skipped. + * } + * ], callback); + * + * // es2017 example, though `asyncify` is not needed if your JS environment + * // supports async functions out of the box + * var q = async.queue(async.asyncify(async function(file) { + * var intermediateStep = await processFile(file); + * return await somePromise(intermediateStep) + * })); + * + * q.push(files); + */ + function asyncify(func) { + if (isAsync(func)) { + return function (...args/*, callback*/) { + const callback = args.pop(); + const promise = func.apply(this, args); + return handlePromise(promise, callback) + } + } + + return initialParams(function (args, callback) { + var result; + try { + result = func.apply(this, args); + } catch (e) { + return callback(e); + } + // if result is Promise object + if (result && typeof result.then === 'function') { + return handlePromise(result, callback) + } else { + callback(null, result); + } + }); + } + + function handlePromise(promise, callback) { + return promise.then(value => { + invokeCallback(callback, null, value); + }, err => { + invokeCallback(callback, err && err.message ? err : new Error(err)); + }); + } + + function invokeCallback(callback, error, value) { + try { + callback(error, value); + } catch (err) { + setImmediate$1(e => { throw e }, err); + } + } + + function isAsync(fn) { + return fn[Symbol.toStringTag] === 'AsyncFunction'; + } + + function isAsyncGenerator(fn) { + return fn[Symbol.toStringTag] === 'AsyncGenerator'; + } + + function isAsyncIterable(obj) { + return typeof obj[Symbol.asyncIterator] === 'function'; + } + + function wrapAsync(asyncFn) { + if (typeof asyncFn !== 'function') throw new Error('expected a function') + return isAsync(asyncFn) ? asyncify(asyncFn) : asyncFn; + } + + // conditionally promisify a function. + // only return a promise if a callback is omitted + function awaitify (asyncFn, arity = asyncFn.length) { + if (!arity) throw new Error('arity is undefined') + function awaitable (...args) { + if (typeof args[arity - 1] === 'function') { + return asyncFn.apply(this, args) + } + + return new Promise((resolve, reject) => { + args[arity - 1] = (err, ...cbArgs) => { + if (err) return reject(err) + resolve(cbArgs.length > 1 ? cbArgs : cbArgs[0]); + }; + asyncFn.apply(this, args); + }) + } + + return awaitable + } + + function applyEach (eachfn) { + return function applyEach(fns, ...callArgs) { + const go = awaitify(function (callback) { + var that = this; + return eachfn(fns, (fn, cb) => { + wrapAsync(fn).apply(that, callArgs.concat(cb)); + }, callback); + }); + return go; + }; + } + + function _asyncMap(eachfn, arr, iteratee, callback) { + arr = arr || []; + var results = []; + var counter = 0; + var _iteratee = wrapAsync(iteratee); + + return eachfn(arr, (value, _, iterCb) => { + var index = counter++; + _iteratee(value, (err, v) => { + results[index] = v; + iterCb(err); + }); + }, err => { + callback(err, results); + }); + } + + function isArrayLike(value) { + return value && + typeof value.length === 'number' && + value.length >= 0 && + value.length % 1 === 0; + } + + // A temporary value used to identify if the loop should be broken. + // See #1064, #1293 + const breakLoop = {}; + + function once(fn) { + function wrapper (...args) { + if (fn === null) return; + var callFn = fn; + fn = null; + callFn.apply(this, args); + } + Object.assign(wrapper, fn); + return wrapper + } + + function getIterator (coll) { + return coll[Symbol.iterator] && coll[Symbol.iterator](); + } + + function createArrayIterator(coll) { + var i = -1; + var len = coll.length; + return function next() { + return ++i < len ? {value: coll[i], key: i} : null; + } + } + + function createES2015Iterator(iterator) { + var i = -1; + return function next() { + var item = iterator.next(); + if (item.done) + return null; + i++; + return {value: item.value, key: i}; + } + } + + function createObjectIterator(obj) { + var okeys = obj ? Object.keys(obj) : []; + var i = -1; + var len = okeys.length; + return function next() { + var key = okeys[++i]; + if (key === '__proto__') { + return next(); + } + return i < len ? {value: obj[key], key} : null; + }; + } + + function createIterator(coll) { + if (isArrayLike(coll)) { + return createArrayIterator(coll); + } + + var iterator = getIterator(coll); + return iterator ? createES2015Iterator(iterator) : createObjectIterator(coll); + } + + function onlyOnce(fn) { + return function (...args) { + if (fn === null) throw new Error("Callback was already called."); + var callFn = fn; + fn = null; + callFn.apply(this, args); + }; + } + + // for async generators + function asyncEachOfLimit(generator, limit, iteratee, callback) { + let done = false; + let canceled = false; + let awaiting = false; + let running = 0; + let idx = 0; + + function replenish() { + //console.log('replenish') + if (running >= limit || awaiting || done) return + //console.log('replenish awaiting') + awaiting = true; + generator.next().then(({value, done: iterDone}) => { + //console.log('got value', value) + if (canceled || done) return + awaiting = false; + if (iterDone) { + done = true; + if (running <= 0) { + //console.log('done nextCb') + callback(null); + } + return; + } + running++; + iteratee(value, idx, iterateeCallback); + idx++; + replenish(); + }).catch(handleError); + } + + function iterateeCallback(err, result) { + //console.log('iterateeCallback') + running -= 1; + if (canceled) return + if (err) return handleError(err) + + if (err === false) { + done = true; + canceled = true; + return + } + + if (result === breakLoop || (done && running <= 0)) { + done = true; + //console.log('done iterCb') + return callback(null); + } + replenish(); + } + + function handleError(err) { + if (canceled) return + awaiting = false; + done = true; + callback(err); + } + + replenish(); + } + + var eachOfLimit = (limit) => { + return (obj, iteratee, callback) => { + callback = once(callback); + if (limit <= 0) { + throw new RangeError('concurrency limit cannot be less than 1') + } + if (!obj) { + return callback(null); + } + if (isAsyncGenerator(obj)) { + return asyncEachOfLimit(obj, limit, iteratee, callback) + } + if (isAsyncIterable(obj)) { + return asyncEachOfLimit(obj[Symbol.asyncIterator](), limit, iteratee, callback) + } + var nextElem = createIterator(obj); + var done = false; + var canceled = false; + var running = 0; + var looping = false; + + function iterateeCallback(err, value) { + if (canceled) return + running -= 1; + if (err) { + done = true; + callback(err); + } + else if (err === false) { + done = true; + canceled = true; + } + else if (value === breakLoop || (done && running <= 0)) { + done = true; + return callback(null); + } + else if (!looping) { + replenish(); + } + } + + function replenish () { + looping = true; + while (running < limit && !done) { + var elem = nextElem(); + if (elem === null) { + done = true; + if (running <= 0) { + callback(null); + } + return; + } + running += 1; + iteratee(elem.value, elem.key, onlyOnce(iterateeCallback)); + } + looping = false; + } + + replenish(); + }; + }; + + /** + * The same as [`eachOf`]{@link module:Collections.eachOf} but runs a maximum of `limit` async operations at a + * time. + * + * @name eachOfLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.eachOf]{@link module:Collections.eachOf} + * @alias forEachOfLimit + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async function to apply to each + * item in `coll`. The `key` is the item's key, or index in the case of an + * array. + * Invoked with (item, key, callback). + * @param {Function} [callback] - A callback which is called when all + * `iteratee` functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + */ + function eachOfLimit$1(coll, limit, iteratee, callback) { + return eachOfLimit(limit)(coll, wrapAsync(iteratee), callback); + } + + var eachOfLimit$2 = awaitify(eachOfLimit$1, 4); + + // eachOf implementation optimized for array-likes + function eachOfArrayLike(coll, iteratee, callback) { + callback = once(callback); + var index = 0, + completed = 0, + {length} = coll, + canceled = false; + if (length === 0) { + callback(null); + } + + function iteratorCallback(err, value) { + if (err === false) { + canceled = true; + } + if (canceled === true) return + if (err) { + callback(err); + } else if ((++completed === length) || value === breakLoop) { + callback(null); + } + } + + for (; index < length; index++) { + iteratee(coll[index], index, onlyOnce(iteratorCallback)); + } + } + + // a generic version of eachOf which can handle array, object, and iterator cases. + function eachOfGeneric (coll, iteratee, callback) { + return eachOfLimit$2(coll, Infinity, iteratee, callback); + } + + /** + * Like [`each`]{@link module:Collections.each}, except that it passes the key (or index) as the second argument + * to the iteratee. + * + * @name eachOf + * @static + * @memberOf module:Collections + * @method + * @alias forEachOf + * @category Collection + * @see [async.each]{@link module:Collections.each} + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - A function to apply to each + * item in `coll`. + * The `key` is the item's key, or index in the case of an array. + * Invoked with (item, key, callback). + * @param {Function} [callback] - A callback which is called when all + * `iteratee` functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + * @example + * + * // dev.json is a file containing a valid json object config for dev environment + * // dev.json is a file containing a valid json object config for test environment + * // prod.json is a file containing a valid json object config for prod environment + * // invalid.json is a file with a malformed json object + * + * let configs = {}; //global variable + * let validConfigFileMap = {dev: 'dev.json', test: 'test.json', prod: 'prod.json'}; + * let invalidConfigFileMap = {dev: 'dev.json', test: 'test.json', invalid: 'invalid.json'}; + * + * // asynchronous function that reads a json file and parses the contents as json object + * function parseFile(file, key, callback) { + * fs.readFile(file, "utf8", function(err, data) { + * if (err) return calback(err); + * try { + * configs[key] = JSON.parse(data); + * } catch (e) { + * return callback(e); + * } + * callback(); + * }); + * } + * + * // Using callbacks + * async.forEachOf(validConfigFileMap, parseFile, function (err) { + * if (err) { + * console.error(err); + * } else { + * console.log(configs); + * // configs is now a map of JSON data, e.g. + * // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json} + * } + * }); + * + * //Error handing + * async.forEachOf(invalidConfigFileMap, parseFile, function (err) { + * if (err) { + * console.error(err); + * // JSON parse error exception + * } else { + * console.log(configs); + * } + * }); + * + * // Using Promises + * async.forEachOf(validConfigFileMap, parseFile) + * .then( () => { + * console.log(configs); + * // configs is now a map of JSON data, e.g. + * // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json} + * }).catch( err => { + * console.error(err); + * }); + * + * //Error handing + * async.forEachOf(invalidConfigFileMap, parseFile) + * .then( () => { + * console.log(configs); + * }).catch( err => { + * console.error(err); + * // JSON parse error exception + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.forEachOf(validConfigFileMap, parseFile); + * console.log(configs); + * // configs is now a map of JSON data, e.g. + * // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json} + * } + * catch (err) { + * console.log(err); + * } + * } + * + * //Error handing + * async () => { + * try { + * let result = await async.forEachOf(invalidConfigFileMap, parseFile); + * console.log(configs); + * } + * catch (err) { + * console.log(err); + * // JSON parse error exception + * } + * } + * + */ + function eachOf(coll, iteratee, callback) { + var eachOfImplementation = isArrayLike(coll) ? eachOfArrayLike : eachOfGeneric; + return eachOfImplementation(coll, wrapAsync(iteratee), callback); + } + + var eachOf$1 = awaitify(eachOf, 3); + + /** + * Produces a new collection of values by mapping each value in `coll` through + * the `iteratee` function. The `iteratee` is called with an item from `coll` + * and a callback for when it has finished processing. Each of these callbacks + * takes 2 arguments: an `error`, and the transformed item from `coll`. If + * `iteratee` passes an error to its callback, the main `callback` (for the + * `map` function) is immediately called with the error. + * + * Note, that since this function applies the `iteratee` to each item in + * parallel, there is no guarantee that the `iteratee` functions will complete + * in order. However, the results array will be in the same order as the + * original `coll`. + * + * If `map` is passed an Object, the results will be an Array. The results + * will roughly be in the order of the original Objects' keys (but this can + * vary across JavaScript engines). + * + * @name map + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with the transformed item. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Results is an Array of the + * transformed items from the `coll`. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * // file4.txt does not exist + * + * const fileList = ['file1.txt','file2.txt','file3.txt']; + * const withMissingFileList = ['file1.txt','file2.txt','file4.txt']; + * + * // asynchronous function that returns the file size in bytes + * function getFileSizeInBytes(file, callback) { + * fs.stat(file, function(err, stat) { + * if (err) { + * return callback(err); + * } + * callback(null, stat.size); + * }); + * } + * + * // Using callbacks + * async.map(fileList, getFileSizeInBytes, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now an array of the file size in bytes for each file, e.g. + * // [ 1000, 2000, 3000] + * } + * }); + * + * // Error Handling + * async.map(withMissingFileList, getFileSizeInBytes, function(err, results) { + * if (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } else { + * console.log(results); + * } + * }); + * + * // Using Promises + * async.map(fileList, getFileSizeInBytes) + * .then( results => { + * console.log(results); + * // results is now an array of the file size in bytes for each file, e.g. + * // [ 1000, 2000, 3000] + * }).catch( err => { + * console.log(err); + * }); + * + * // Error Handling + * async.map(withMissingFileList, getFileSizeInBytes) + * .then( results => { + * console.log(results); + * }).catch( err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * }); + * + * // Using async/await + * async () => { + * try { + * let results = await async.map(fileList, getFileSizeInBytes); + * console.log(results); + * // results is now an array of the file size in bytes for each file, e.g. + * // [ 1000, 2000, 3000] + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // Error Handling + * async () => { + * try { + * let results = await async.map(withMissingFileList, getFileSizeInBytes); + * console.log(results); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } + * } + * + */ + function map (coll, iteratee, callback) { + return _asyncMap(eachOf$1, coll, iteratee, callback) + } + var map$1 = awaitify(map, 3); + + /** + * Applies the provided arguments to each function in the array, calling + * `callback` after all functions have completed. If you only provide the first + * argument, `fns`, then it will return a function which lets you pass in the + * arguments as if it were a single function call. If more arguments are + * provided, `callback` is required while `args` is still optional. The results + * for each of the applied async functions are passed to the final callback + * as an array. + * + * @name applyEach + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s + * to all call with the same arguments + * @param {...*} [args] - any number of separate arguments to pass to the + * function. + * @param {Function} [callback] - the final argument should be the callback, + * called when all functions have completed processing. + * @returns {AsyncFunction} - Returns a function that takes no args other than + * an optional callback, that is the result of applying the `args` to each + * of the functions. + * @example + * + * const appliedFn = async.applyEach([enableSearch, updateSchema], 'bucket') + * + * appliedFn((err, results) => { + * // results[0] is the results for `enableSearch` + * // results[1] is the results for `updateSchema` + * }); + * + * // partial application example: + * async.each( + * buckets, + * async (bucket) => async.applyEach([enableSearch, updateSchema], bucket)(), + * callback + * ); + */ + var applyEach$1 = applyEach(map$1); + + /** + * The same as [`eachOf`]{@link module:Collections.eachOf} but runs only a single async operation at a time. + * + * @name eachOfSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.eachOf]{@link module:Collections.eachOf} + * @alias forEachOfSeries + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * Invoked with (item, key, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + */ + function eachOfSeries(coll, iteratee, callback) { + return eachOfLimit$2(coll, 1, iteratee, callback) + } + var eachOfSeries$1 = awaitify(eachOfSeries, 3); + + /** + * The same as [`map`]{@link module:Collections.map} but runs only a single async operation at a time. + * + * @name mapSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.map]{@link module:Collections.map} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with the transformed item. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Results is an array of the + * transformed items from the `coll`. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + */ + function mapSeries (coll, iteratee, callback) { + return _asyncMap(eachOfSeries$1, coll, iteratee, callback) + } + var mapSeries$1 = awaitify(mapSeries, 3); + + /** + * The same as [`applyEach`]{@link module:ControlFlow.applyEach} but runs only a single async operation at a time. + * + * @name applyEachSeries + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.applyEach]{@link module:ControlFlow.applyEach} + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s to all + * call with the same arguments + * @param {...*} [args] - any number of separate arguments to pass to the + * function. + * @param {Function} [callback] - the final argument should be the callback, + * called when all functions have completed processing. + * @returns {AsyncFunction} - A function, that when called, is the result of + * appling the `args` to the list of functions. It takes no args, other than + * a callback. + */ + var applyEachSeries = applyEach(mapSeries$1); + + const PROMISE_SYMBOL = Symbol('promiseCallback'); + + function promiseCallback () { + let resolve, reject; + function callback (err, ...args) { + if (err) return reject(err) + resolve(args.length > 1 ? args : args[0]); + } + + callback[PROMISE_SYMBOL] = new Promise((res, rej) => { + resolve = res, + reject = rej; + }); + + return callback + } + + /** + * Determines the best order for running the {@link AsyncFunction}s in `tasks`, based on + * their requirements. Each function can optionally depend on other functions + * being completed first, and each function is run as soon as its requirements + * are satisfied. + * + * If any of the {@link AsyncFunction}s pass an error to their callback, the `auto` sequence + * will stop. Further tasks will not execute (so any other functions depending + * on it will not run), and the main `callback` is immediately called with the + * error. + * + * {@link AsyncFunction}s also receive an object containing the results of functions which + * have completed so far as the first argument, if they have dependencies. If a + * task function has no dependencies, it will only be passed a callback. + * + * @name auto + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Object} tasks - An object. Each of its properties is either a + * function or an array of requirements, with the {@link AsyncFunction} itself the last item + * in the array. The object's key of a property serves as the name of the task + * defined by that property, i.e. can be used when specifying requirements for + * other tasks. The function receives one or two arguments: + * * a `results` object, containing the results of the previously executed + * functions, only passed if the task has any dependencies, + * * a `callback(err, result)` function, which must be called when finished, + * passing an `error` (which can be `null`) and the result of the function's + * execution. + * @param {number} [concurrency=Infinity] - An optional `integer` for + * determining the maximum number of tasks that can be run in parallel. By + * default, as many as possible. + * @param {Function} [callback] - An optional callback which is called when all + * the tasks have been completed. It receives the `err` argument if any `tasks` + * pass an error to their callback. Results are always returned; however, if an + * error occurs, no further `tasks` will be performed, and the results object + * will only contain partial results. Invoked with (err, results). + * @returns {Promise} a promise, if a callback is not passed + * @example + * + * //Using Callbacks + * async.auto({ + * get_data: function(callback) { + * // async code to get some data + * callback(null, 'data', 'converted to array'); + * }, + * make_folder: function(callback) { + * // async code to create a directory to store a file in + * // this is run at the same time as getting the data + * callback(null, 'folder'); + * }, + * write_file: ['get_data', 'make_folder', function(results, callback) { + * // once there is some data and the directory exists, + * // write the data to a file in the directory + * callback(null, 'filename'); + * }], + * email_link: ['write_file', function(results, callback) { + * // once the file is written let's email a link to it... + * callback(null, {'file':results.write_file, 'email':'user@example.com'}); + * }] + * }, function(err, results) { + * if (err) { + * console.log('err = ', err); + * } + * console.log('results = ', results); + * // results = { + * // get_data: ['data', 'converted to array'] + * // make_folder; 'folder', + * // write_file: 'filename' + * // email_link: { file: 'filename', email: 'user@example.com' } + * // } + * }); + * + * //Using Promises + * async.auto({ + * get_data: function(callback) { + * console.log('in get_data'); + * // async code to get some data + * callback(null, 'data', 'converted to array'); + * }, + * make_folder: function(callback) { + * console.log('in make_folder'); + * // async code to create a directory to store a file in + * // this is run at the same time as getting the data + * callback(null, 'folder'); + * }, + * write_file: ['get_data', 'make_folder', function(results, callback) { + * // once there is some data and the directory exists, + * // write the data to a file in the directory + * callback(null, 'filename'); + * }], + * email_link: ['write_file', function(results, callback) { + * // once the file is written let's email a link to it... + * callback(null, {'file':results.write_file, 'email':'user@example.com'}); + * }] + * }).then(results => { + * console.log('results = ', results); + * // results = { + * // get_data: ['data', 'converted to array'] + * // make_folder; 'folder', + * // write_file: 'filename' + * // email_link: { file: 'filename', email: 'user@example.com' } + * // } + * }).catch(err => { + * console.log('err = ', err); + * }); + * + * //Using async/await + * async () => { + * try { + * let results = await async.auto({ + * get_data: function(callback) { + * // async code to get some data + * callback(null, 'data', 'converted to array'); + * }, + * make_folder: function(callback) { + * // async code to create a directory to store a file in + * // this is run at the same time as getting the data + * callback(null, 'folder'); + * }, + * write_file: ['get_data', 'make_folder', function(results, callback) { + * // once there is some data and the directory exists, + * // write the data to a file in the directory + * callback(null, 'filename'); + * }], + * email_link: ['write_file', function(results, callback) { + * // once the file is written let's email a link to it... + * callback(null, {'file':results.write_file, 'email':'user@example.com'}); + * }] + * }); + * console.log('results = ', results); + * // results = { + * // get_data: ['data', 'converted to array'] + * // make_folder; 'folder', + * // write_file: 'filename' + * // email_link: { file: 'filename', email: 'user@example.com' } + * // } + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function auto(tasks, concurrency, callback) { + if (typeof concurrency !== 'number') { + // concurrency is optional, shift the args. + callback = concurrency; + concurrency = null; + } + callback = once(callback || promiseCallback()); + var numTasks = Object.keys(tasks).length; + if (!numTasks) { + return callback(null); + } + if (!concurrency) { + concurrency = numTasks; + } + + var results = {}; + var runningTasks = 0; + var canceled = false; + var hasError = false; + + var listeners = Object.create(null); + + var readyTasks = []; + + // for cycle detection: + var readyToCheck = []; // tasks that have been identified as reachable + // without the possibility of returning to an ancestor task + var uncheckedDependencies = {}; + + Object.keys(tasks).forEach(key => { + var task = tasks[key]; + if (!Array.isArray(task)) { + // no dependencies + enqueueTask(key, [task]); + readyToCheck.push(key); + return; + } + + var dependencies = task.slice(0, task.length - 1); + var remainingDependencies = dependencies.length; + if (remainingDependencies === 0) { + enqueueTask(key, task); + readyToCheck.push(key); + return; + } + uncheckedDependencies[key] = remainingDependencies; + + dependencies.forEach(dependencyName => { + if (!tasks[dependencyName]) { + throw new Error('async.auto task `' + key + + '` has a non-existent dependency `' + + dependencyName + '` in ' + + dependencies.join(', ')); + } + addListener(dependencyName, () => { + remainingDependencies--; + if (remainingDependencies === 0) { + enqueueTask(key, task); + } + }); + }); + }); + + checkForDeadlocks(); + processQueue(); + + function enqueueTask(key, task) { + readyTasks.push(() => runTask(key, task)); + } + + function processQueue() { + if (canceled) return + if (readyTasks.length === 0 && runningTasks === 0) { + return callback(null, results); + } + while(readyTasks.length && runningTasks < concurrency) { + var run = readyTasks.shift(); + run(); + } + + } + + function addListener(taskName, fn) { + var taskListeners = listeners[taskName]; + if (!taskListeners) { + taskListeners = listeners[taskName] = []; + } + + taskListeners.push(fn); + } + + function taskComplete(taskName) { + var taskListeners = listeners[taskName] || []; + taskListeners.forEach(fn => fn()); + processQueue(); + } + + + function runTask(key, task) { + if (hasError) return; + + var taskCallback = onlyOnce((err, ...result) => { + runningTasks--; + if (err === false) { + canceled = true; + return + } + if (result.length < 2) { + [result] = result; + } + if (err) { + var safeResults = {}; + Object.keys(results).forEach(rkey => { + safeResults[rkey] = results[rkey]; + }); + safeResults[key] = result; + hasError = true; + listeners = Object.create(null); + if (canceled) return + callback(err, safeResults); + } else { + results[key] = result; + taskComplete(key); + } + }); + + runningTasks++; + var taskFn = wrapAsync(task[task.length - 1]); + if (task.length > 1) { + taskFn(results, taskCallback); + } else { + taskFn(taskCallback); + } + } + + function checkForDeadlocks() { + // Kahn's algorithm + // https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm + // http://connalle.blogspot.com/2013/10/topological-sortingkahn-algorithm.html + var currentTask; + var counter = 0; + while (readyToCheck.length) { + currentTask = readyToCheck.pop(); + counter++; + getDependents(currentTask).forEach(dependent => { + if (--uncheckedDependencies[dependent] === 0) { + readyToCheck.push(dependent); + } + }); + } + + if (counter !== numTasks) { + throw new Error( + 'async.auto cannot execute tasks due to a recursive dependency' + ); + } + } + + function getDependents(taskName) { + var result = []; + Object.keys(tasks).forEach(key => { + const task = tasks[key]; + if (Array.isArray(task) && task.indexOf(taskName) >= 0) { + result.push(key); + } + }); + return result; + } + + return callback[PROMISE_SYMBOL] + } + + var FN_ARGS = /^(?:async\s+)?(?:function)?\s*\w*\s*\(\s*([^)]+)\s*\)(?:\s*{)/; + var ARROW_FN_ARGS = /^(?:async\s+)?\(?\s*([^)=]+)\s*\)?(?:\s*=>)/; + var FN_ARG_SPLIT = /,/; + var FN_ARG = /(=.+)?(\s*)$/; + + function stripComments(string) { + let stripped = ''; + let index = 0; + let endBlockComment = string.indexOf('*/'); + while (index < string.length) { + if (string[index] === '/' && string[index+1] === '/') { + // inline comment + let endIndex = string.indexOf('\n', index); + index = (endIndex === -1) ? string.length : endIndex; + } else if ((endBlockComment !== -1) && (string[index] === '/') && (string[index+1] === '*')) { + // block comment + let endIndex = string.indexOf('*/', index); + if (endIndex !== -1) { + index = endIndex + 2; + endBlockComment = string.indexOf('*/', index); + } else { + stripped += string[index]; + index++; + } + } else { + stripped += string[index]; + index++; + } + } + return stripped; + } + + function parseParams(func) { + const src = stripComments(func.toString()); + let match = src.match(FN_ARGS); + if (!match) { + match = src.match(ARROW_FN_ARGS); + } + if (!match) throw new Error('could not parse args in autoInject\nSource:\n' + src) + let [, args] = match; + return args + .replace(/\s/g, '') + .split(FN_ARG_SPLIT) + .map((arg) => arg.replace(FN_ARG, '').trim()); + } + + /** + * A dependency-injected version of the [async.auto]{@link module:ControlFlow.auto} function. Dependent + * tasks are specified as parameters to the function, after the usual callback + * parameter, with the parameter names matching the names of the tasks it + * depends on. This can provide even more readable task graphs which can be + * easier to maintain. + * + * If a final callback is specified, the task results are similarly injected, + * specified as named parameters after the initial error parameter. + * + * The autoInject function is purely syntactic sugar and its semantics are + * otherwise equivalent to [async.auto]{@link module:ControlFlow.auto}. + * + * @name autoInject + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.auto]{@link module:ControlFlow.auto} + * @category Control Flow + * @param {Object} tasks - An object, each of whose properties is an {@link AsyncFunction} of + * the form 'func([dependencies...], callback). The object's key of a property + * serves as the name of the task defined by that property, i.e. can be used + * when specifying requirements for other tasks. + * * The `callback` parameter is a `callback(err, result)` which must be called + * when finished, passing an `error` (which can be `null`) and the result of + * the function's execution. The remaining parameters name other tasks on + * which the task is dependent, and the results from those tasks are the + * arguments of those parameters. + * @param {Function} [callback] - An optional callback which is called when all + * the tasks have been completed. It receives the `err` argument if any `tasks` + * pass an error to their callback, and a `results` object with any completed + * task results, similar to `auto`. + * @returns {Promise} a promise, if no callback is passed + * @example + * + * // The example from `auto` can be rewritten as follows: + * async.autoInject({ + * get_data: function(callback) { + * // async code to get some data + * callback(null, 'data', 'converted to array'); + * }, + * make_folder: function(callback) { + * // async code to create a directory to store a file in + * // this is run at the same time as getting the data + * callback(null, 'folder'); + * }, + * write_file: function(get_data, make_folder, callback) { + * // once there is some data and the directory exists, + * // write the data to a file in the directory + * callback(null, 'filename'); + * }, + * email_link: function(write_file, callback) { + * // once the file is written let's email a link to it... + * // write_file contains the filename returned by write_file. + * callback(null, {'file':write_file, 'email':'user@example.com'}); + * } + * }, function(err, results) { + * console.log('err = ', err); + * console.log('email_link = ', results.email_link); + * }); + * + * // If you are using a JS minifier that mangles parameter names, `autoInject` + * // will not work with plain functions, since the parameter names will be + * // collapsed to a single letter identifier. To work around this, you can + * // explicitly specify the names of the parameters your task function needs + * // in an array, similar to Angular.js dependency injection. + * + * // This still has an advantage over plain `auto`, since the results a task + * // depends on are still spread into arguments. + * async.autoInject({ + * //... + * write_file: ['get_data', 'make_folder', function(get_data, make_folder, callback) { + * callback(null, 'filename'); + * }], + * email_link: ['write_file', function(write_file, callback) { + * callback(null, {'file':write_file, 'email':'user@example.com'}); + * }] + * //... + * }, function(err, results) { + * console.log('err = ', err); + * console.log('email_link = ', results.email_link); + * }); + */ + function autoInject(tasks, callback) { + var newTasks = {}; + + Object.keys(tasks).forEach(key => { + var taskFn = tasks[key]; + var params; + var fnIsAsync = isAsync(taskFn); + var hasNoDeps = + (!fnIsAsync && taskFn.length === 1) || + (fnIsAsync && taskFn.length === 0); + + if (Array.isArray(taskFn)) { + params = [...taskFn]; + taskFn = params.pop(); + + newTasks[key] = params.concat(params.length > 0 ? newTask : taskFn); + } else if (hasNoDeps) { + // no dependencies, use the function as-is + newTasks[key] = taskFn; + } else { + params = parseParams(taskFn); + if ((taskFn.length === 0 && !fnIsAsync) && params.length === 0) { + throw new Error("autoInject task functions require explicit parameters."); + } + + // remove callback param + if (!fnIsAsync) params.pop(); + + newTasks[key] = params.concat(newTask); + } + + function newTask(results, taskCb) { + var newArgs = params.map(name => results[name]); + newArgs.push(taskCb); + wrapAsync(taskFn)(...newArgs); + } + }); + + return auto(newTasks, callback); + } + + // Simple doubly linked list (https://en.wikipedia.org/wiki/Doubly_linked_list) implementation + // used for queues. This implementation assumes that the node provided by the user can be modified + // to adjust the next and last properties. We implement only the minimal functionality + // for queue support. + class DLL { + constructor() { + this.head = this.tail = null; + this.length = 0; + } + + removeLink(node) { + if (node.prev) node.prev.next = node.next; + else this.head = node.next; + if (node.next) node.next.prev = node.prev; + else this.tail = node.prev; + + node.prev = node.next = null; + this.length -= 1; + return node; + } + + empty () { + while(this.head) this.shift(); + return this; + } + + insertAfter(node, newNode) { + newNode.prev = node; + newNode.next = node.next; + if (node.next) node.next.prev = newNode; + else this.tail = newNode; + node.next = newNode; + this.length += 1; + } + + insertBefore(node, newNode) { + newNode.prev = node.prev; + newNode.next = node; + if (node.prev) node.prev.next = newNode; + else this.head = newNode; + node.prev = newNode; + this.length += 1; + } + + unshift(node) { + if (this.head) this.insertBefore(this.head, node); + else setInitial(this, node); + } + + push(node) { + if (this.tail) this.insertAfter(this.tail, node); + else setInitial(this, node); + } + + shift() { + return this.head && this.removeLink(this.head); + } + + pop() { + return this.tail && this.removeLink(this.tail); + } + + toArray() { + return [...this] + } + + *[Symbol.iterator] () { + var cur = this.head; + while (cur) { + yield cur.data; + cur = cur.next; + } + } + + remove (testFn) { + var curr = this.head; + while(curr) { + var {next} = curr; + if (testFn(curr)) { + this.removeLink(curr); + } + curr = next; + } + return this; + } + } + + function setInitial(dll, node) { + dll.length = 1; + dll.head = dll.tail = node; + } + + function queue(worker, concurrency, payload) { + if (concurrency == null) { + concurrency = 1; + } + else if(concurrency === 0) { + throw new RangeError('Concurrency must not be zero'); + } + + var _worker = wrapAsync(worker); + var numRunning = 0; + var workersList = []; + const events = { + error: [], + drain: [], + saturated: [], + unsaturated: [], + empty: [] + }; + + function on (event, handler) { + events[event].push(handler); + } + + function once (event, handler) { + const handleAndRemove = (...args) => { + off(event, handleAndRemove); + handler(...args); + }; + events[event].push(handleAndRemove); + } + + function off (event, handler) { + if (!event) return Object.keys(events).forEach(ev => events[ev] = []) + if (!handler) return events[event] = [] + events[event] = events[event].filter(ev => ev !== handler); + } + + function trigger (event, ...args) { + events[event].forEach(handler => handler(...args)); + } + + var processingScheduled = false; + function _insert(data, insertAtFront, rejectOnError, callback) { + if (callback != null && typeof callback !== 'function') { + throw new Error('task callback must be a function'); + } + q.started = true; + + var res, rej; + function promiseCallback (err, ...args) { + // we don't care about the error, let the global error handler + // deal with it + if (err) return rejectOnError ? rej(err) : res() + if (args.length <= 1) return res(args[0]) + res(args); + } + + var item = q._createTaskItem( + data, + rejectOnError ? promiseCallback : + (callback || promiseCallback) + ); + + if (insertAtFront) { + q._tasks.unshift(item); + } else { + q._tasks.push(item); + } + + if (!processingScheduled) { + processingScheduled = true; + setImmediate$1(() => { + processingScheduled = false; + q.process(); + }); + } + + if (rejectOnError || !callback) { + return new Promise((resolve, reject) => { + res = resolve; + rej = reject; + }) + } + } + + function _createCB(tasks) { + return function (err, ...args) { + numRunning -= 1; + + for (var i = 0, l = tasks.length; i < l; i++) { + var task = tasks[i]; + + var index = workersList.indexOf(task); + if (index === 0) { + workersList.shift(); + } else if (index > 0) { + workersList.splice(index, 1); + } + + task.callback(err, ...args); + + if (err != null) { + trigger('error', err, task.data); + } + } + + if (numRunning <= (q.concurrency - q.buffer) ) { + trigger('unsaturated'); + } + + if (q.idle()) { + trigger('drain'); + } + q.process(); + }; + } + + function _maybeDrain(data) { + if (data.length === 0 && q.idle()) { + // call drain immediately if there are no tasks + setImmediate$1(() => trigger('drain')); + return true + } + return false + } + + const eventMethod = (name) => (handler) => { + if (!handler) { + return new Promise((resolve, reject) => { + once(name, (err, data) => { + if (err) return reject(err) + resolve(data); + }); + }) + } + off(name); + on(name, handler); + + }; + + var isProcessing = false; + var q = { + _tasks: new DLL(), + _createTaskItem (data, callback) { + return { + data, + callback + }; + }, + *[Symbol.iterator] () { + yield* q._tasks[Symbol.iterator](); + }, + concurrency, + payload, + buffer: concurrency / 4, + started: false, + paused: false, + push (data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return + return data.map(datum => _insert(datum, false, false, callback)) + } + return _insert(data, false, false, callback); + }, + pushAsync (data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return + return data.map(datum => _insert(datum, false, true, callback)) + } + return _insert(data, false, true, callback); + }, + kill () { + off(); + q._tasks.empty(); + }, + unshift (data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return + return data.map(datum => _insert(datum, true, false, callback)) + } + return _insert(data, true, false, callback); + }, + unshiftAsync (data, callback) { + if (Array.isArray(data)) { + if (_maybeDrain(data)) return + return data.map(datum => _insert(datum, true, true, callback)) + } + return _insert(data, true, true, callback); + }, + remove (testFn) { + q._tasks.remove(testFn); + }, + process () { + // Avoid trying to start too many processing operations. This can occur + // when callbacks resolve synchronously (#1267). + if (isProcessing) { + return; + } + isProcessing = true; + while(!q.paused && numRunning < q.concurrency && q._tasks.length){ + var tasks = [], data = []; + var l = q._tasks.length; + if (q.payload) l = Math.min(l, q.payload); + for (var i = 0; i < l; i++) { + var node = q._tasks.shift(); + tasks.push(node); + workersList.push(node); + data.push(node.data); + } + + numRunning += 1; + + if (q._tasks.length === 0) { + trigger('empty'); + } + + if (numRunning === q.concurrency) { + trigger('saturated'); + } + + var cb = onlyOnce(_createCB(tasks)); + _worker(data, cb); + } + isProcessing = false; + }, + length () { + return q._tasks.length; + }, + running () { + return numRunning; + }, + workersList () { + return workersList; + }, + idle() { + return q._tasks.length + numRunning === 0; + }, + pause () { + q.paused = true; + }, + resume () { + if (q.paused === false) { return; } + q.paused = false; + setImmediate$1(q.process); + } + }; + // define these as fixed properties, so people get useful errors when updating + Object.defineProperties(q, { + saturated: { + writable: false, + value: eventMethod('saturated') + }, + unsaturated: { + writable: false, + value: eventMethod('unsaturated') + }, + empty: { + writable: false, + value: eventMethod('empty') + }, + drain: { + writable: false, + value: eventMethod('drain') + }, + error: { + writable: false, + value: eventMethod('error') + }, + }); + return q; + } + + /** + * Creates a `cargo` object with the specified payload. Tasks added to the + * cargo will be processed altogether (up to the `payload` limit). If the + * `worker` is in progress, the task is queued until it becomes available. Once + * the `worker` has completed some tasks, each callback of those tasks is + * called. Check out [these](https://camo.githubusercontent.com/6bbd36f4cf5b35a0f11a96dcd2e97711ffc2fb37/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130382f62626330636662302d356632392d313165322d393734662d3333393763363464633835382e676966) [animations](https://camo.githubusercontent.com/f4810e00e1c5f5f8addbe3e9f49064fd5d102699/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130312f38346339323036362d356632392d313165322d383134662d3964336430323431336266642e676966) + * for how `cargo` and `queue` work. + * + * While [`queue`]{@link module:ControlFlow.queue} passes only one task to one of a group of workers + * at a time, cargo passes an array of tasks to a single worker, repeating + * when the worker is finished. + * + * @name cargo + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.queue]{@link module:ControlFlow.queue} + * @category Control Flow + * @param {AsyncFunction} worker - An asynchronous function for processing an array + * of queued tasks. Invoked with `(tasks, callback)`. + * @param {number} [payload=Infinity] - An optional `integer` for determining + * how many tasks should be processed per round; if omitted, the default is + * unlimited. + * @returns {module:ControlFlow.QueueObject} A cargo object to manage the tasks. Callbacks can + * attached as certain properties to listen for specific events during the + * lifecycle of the cargo and inner queue. + * @example + * + * // create a cargo object with payload 2 + * var cargo = async.cargo(function(tasks, callback) { + * for (var i=0; i { + * console.log(result); + * // 6000 + * // which is the sum of the file sizes of the three files + * }).catch( err => { + * console.log(err); + * }); + * + * // Error Handling + * async.reduce(withMissingFileList, 0, getFileSizeInBytes) + * .then( result => { + * console.log(result); + * }).catch( err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.reduce(fileList, 0, getFileSizeInBytes); + * console.log(result); + * // 6000 + * // which is the sum of the file sizes of the three files + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // Error Handling + * async () => { + * try { + * let result = await async.reduce(withMissingFileList, 0, getFileSizeInBytes); + * console.log(result); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } + * } + * + */ + function reduce(coll, memo, iteratee, callback) { + callback = once(callback); + var _iteratee = wrapAsync(iteratee); + return eachOfSeries$1(coll, (x, i, iterCb) => { + _iteratee(memo, x, (err, v) => { + memo = v; + iterCb(err); + }); + }, err => callback(err, memo)); + } + var reduce$1 = awaitify(reduce, 4); + + /** + * Version of the compose function that is more natural to read. Each function + * consumes the return value of the previous function. It is the equivalent of + * [compose]{@link module:ControlFlow.compose} with the arguments reversed. + * + * Each function is executed with the `this` binding of the composed function. + * + * @name seq + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.compose]{@link module:ControlFlow.compose} + * @category Control Flow + * @param {...AsyncFunction} functions - the asynchronous functions to compose + * @returns {Function} a function that composes the `functions` in order + * @example + * + * // Requires lodash (or underscore), express3 and dresende's orm2. + * // Part of an app, that fetches cats of the logged user. + * // This example uses `seq` function to avoid overnesting and error + * // handling clutter. + * app.get('/cats', function(request, response) { + * var User = request.models.User; + * async.seq( + * User.get.bind(User), // 'User.get' has signature (id, callback(err, data)) + * function(user, fn) { + * user.getCats(fn); // 'getCats' has signature (callback(err, data)) + * } + * )(req.session.user_id, function (err, cats) { + * if (err) { + * console.error(err); + * response.json({ status: 'error', message: err.message }); + * } else { + * response.json({ status: 'ok', message: 'Cats found', data: cats }); + * } + * }); + * }); + */ + function seq(...functions) { + var _functions = functions.map(wrapAsync); + return function (...args) { + var that = this; + + var cb = args[args.length - 1]; + if (typeof cb == 'function') { + args.pop(); + } else { + cb = promiseCallback(); + } + + reduce$1(_functions, args, (newargs, fn, iterCb) => { + fn.apply(that, newargs.concat((err, ...nextargs) => { + iterCb(err, nextargs); + })); + }, + (err, results) => cb(err, ...results)); + + return cb[PROMISE_SYMBOL] + }; + } + + /** + * Creates a function which is a composition of the passed asynchronous + * functions. Each function consumes the return value of the function that + * follows. Composing functions `f()`, `g()`, and `h()` would produce the result + * of `f(g(h()))`, only this version uses callbacks to obtain the return values. + * + * If the last argument to the composed function is not a function, a promise + * is returned when you call it. + * + * Each function is executed with the `this` binding of the composed function. + * + * @name compose + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {...AsyncFunction} functions - the asynchronous functions to compose + * @returns {Function} an asynchronous function that is the composed + * asynchronous `functions` + * @example + * + * function add1(n, callback) { + * setTimeout(function () { + * callback(null, n + 1); + * }, 10); + * } + * + * function mul3(n, callback) { + * setTimeout(function () { + * callback(null, n * 3); + * }, 10); + * } + * + * var add1mul3 = async.compose(mul3, add1); + * add1mul3(4, function (err, result) { + * // result now equals 15 + * }); + */ + function compose(...args) { + return seq(...args.reverse()); + } + + /** + * The same as [`map`]{@link module:Collections.map} but runs a maximum of `limit` async operations at a time. + * + * @name mapLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.map]{@link module:Collections.map} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with the transformed item. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Results is an array of the + * transformed items from the `coll`. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + */ + function mapLimit (coll, limit, iteratee, callback) { + return _asyncMap(eachOfLimit(limit), coll, iteratee, callback) + } + var mapLimit$1 = awaitify(mapLimit, 4); + + /** + * The same as [`concat`]{@link module:Collections.concat} but runs a maximum of `limit` async operations at a time. + * + * @name concatLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.concat]{@link module:Collections.concat} + * @category Collection + * @alias flatMapLimit + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`, + * which should use an array as its result. Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished, or an error occurs. Results is an array + * containing the concatenated results of the `iteratee` function. Invoked with + * (err, results). + * @returns A Promise, if no callback is passed + */ + function concatLimit(coll, limit, iteratee, callback) { + var _iteratee = wrapAsync(iteratee); + return mapLimit$1(coll, limit, (val, iterCb) => { + _iteratee(val, (err, ...args) => { + if (err) return iterCb(err); + return iterCb(err, args); + }); + }, (err, mapResults) => { + var result = []; + for (var i = 0; i < mapResults.length; i++) { + if (mapResults[i]) { + result = result.concat(...mapResults[i]); + } + } + + return callback(err, result); + }); + } + var concatLimit$1 = awaitify(concatLimit, 4); + + /** + * Applies `iteratee` to each item in `coll`, concatenating the results. Returns + * the concatenated list. The `iteratee`s are called in parallel, and the + * results are concatenated as they return. The results array will be returned in + * the original order of `coll` passed to the `iteratee` function. + * + * @name concat + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @alias flatMap + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`, + * which should use an array as its result. Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished, or an error occurs. Results is an array + * containing the concatenated results of the `iteratee` function. Invoked with + * (err, results). + * @returns A Promise, if no callback is passed + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * // dir4 does not exist + * + * let directoryList = ['dir1','dir2','dir3']; + * let withMissingDirectoryList = ['dir1','dir2','dir3', 'dir4']; + * + * // Using callbacks + * async.concat(directoryList, fs.readdir, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ] + * } + * }); + * + * // Error Handling + * async.concat(withMissingDirectoryList, fs.readdir, function(err, results) { + * if (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4 does not exist + * } else { + * console.log(results); + * } + * }); + * + * // Using Promises + * async.concat(directoryList, fs.readdir) + * .then(results => { + * console.log(results); + * // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ] + * }).catch(err => { + * console.log(err); + * }); + * + * // Error Handling + * async.concat(withMissingDirectoryList, fs.readdir) + * .then(results => { + * console.log(results); + * }).catch(err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4 does not exist + * }); + * + * // Using async/await + * async () => { + * try { + * let results = await async.concat(directoryList, fs.readdir); + * console.log(results); + * // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ] + * } catch (err) { + * console.log(err); + * } + * } + * + * // Error Handling + * async () => { + * try { + * let results = await async.concat(withMissingDirectoryList, fs.readdir); + * console.log(results); + * } catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4 does not exist + * } + * } + * + */ + function concat(coll, iteratee, callback) { + return concatLimit$1(coll, Infinity, iteratee, callback) + } + var concat$1 = awaitify(concat, 3); + + /** + * The same as [`concat`]{@link module:Collections.concat} but runs only a single async operation at a time. + * + * @name concatSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.concat]{@link module:Collections.concat} + * @category Collection + * @alias flatMapSeries + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`. + * The iteratee should complete with an array an array of results. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished, or an error occurs. Results is an array + * containing the concatenated results of the `iteratee` function. Invoked with + * (err, results). + * @returns A Promise, if no callback is passed + */ + function concatSeries(coll, iteratee, callback) { + return concatLimit$1(coll, 1, iteratee, callback) + } + var concatSeries$1 = awaitify(concatSeries, 3); + + /** + * Returns a function that when called, calls-back with the values provided. + * Useful as the first function in a [`waterfall`]{@link module:ControlFlow.waterfall}, or for plugging values in to + * [`auto`]{@link module:ControlFlow.auto}. + * + * @name constant + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {...*} arguments... - Any number of arguments to automatically invoke + * callback with. + * @returns {AsyncFunction} Returns a function that when invoked, automatically + * invokes the callback with the previous given arguments. + * @example + * + * async.waterfall([ + * async.constant(42), + * function (value, next) { + * // value === 42 + * }, + * //... + * ], callback); + * + * async.waterfall([ + * async.constant(filename, "utf8"), + * fs.readFile, + * function (fileData, next) { + * //... + * } + * //... + * ], callback); + * + * async.auto({ + * hostname: async.constant("https://server.net/"), + * port: findFreePort, + * launchServer: ["hostname", "port", function (options, cb) { + * startServer(options, cb); + * }], + * //... + * }, callback); + */ + function constant(...args) { + return function (...ignoredArgs/*, callback*/) { + var callback = ignoredArgs.pop(); + return callback(null, ...args); + }; + } + + function _createTester(check, getResult) { + return (eachfn, arr, _iteratee, cb) => { + var testPassed = false; + var testResult; + const iteratee = wrapAsync(_iteratee); + eachfn(arr, (value, _, callback) => { + iteratee(value, (err, result) => { + if (err || err === false) return callback(err); + + if (check(result) && !testResult) { + testPassed = true; + testResult = getResult(true, value); + return callback(null, breakLoop); + } + callback(); + }); + }, err => { + if (err) return cb(err); + cb(null, testPassed ? testResult : getResult(false)); + }); + }; + } + + /** + * Returns the first value in `coll` that passes an async truth test. The + * `iteratee` is applied in parallel, meaning the first iteratee to return + * `true` will fire the detect `callback` with that result. That means the + * result might not be the first item in the original `coll` (in terms of order) + * that passes the test. + + * If order within the original `coll` is important, then look at + * [`detectSeries`]{@link module:Collections.detectSeries}. + * + * @name detect + * @static + * @memberOf module:Collections + * @method + * @alias find + * @category Collections + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`. + * The iteratee must complete with a boolean value as its result. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the `iteratee` functions have finished. + * Result will be the first item in the array that passes the truth test + * (iteratee) or the value `undefined` if none passed. Invoked with + * (err, result). + * @returns {Promise} a promise, if a callback is omitted + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * + * // asynchronous function that checks if a file exists + * function fileExists(file, callback) { + * fs.access(file, fs.constants.F_OK, (err) => { + * callback(null, !err); + * }); + * } + * + * async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists, + * function(err, result) { + * console.log(result); + * // dir1/file1.txt + * // result now equals the first file in the list that exists + * } + *); + * + * // Using Promises + * async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists) + * .then(result => { + * console.log(result); + * // dir1/file1.txt + * // result now equals the first file in the list that exists + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists); + * console.log(result); + * // dir1/file1.txt + * // result now equals the file in the list that exists + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function detect(coll, iteratee, callback) { + return _createTester(bool => bool, (res, item) => item)(eachOf$1, coll, iteratee, callback) + } + var detect$1 = awaitify(detect, 3); + + /** + * The same as [`detect`]{@link module:Collections.detect} but runs a maximum of `limit` async operations at a + * time. + * + * @name detectLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.detect]{@link module:Collections.detect} + * @alias findLimit + * @category Collections + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`. + * The iteratee must complete with a boolean value as its result. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the `iteratee` functions have finished. + * Result will be the first item in the array that passes the truth test + * (iteratee) or the value `undefined` if none passed. Invoked with + * (err, result). + * @returns {Promise} a promise, if a callback is omitted + */ + function detectLimit(coll, limit, iteratee, callback) { + return _createTester(bool => bool, (res, item) => item)(eachOfLimit(limit), coll, iteratee, callback) + } + var detectLimit$1 = awaitify(detectLimit, 4); + + /** + * The same as [`detect`]{@link module:Collections.detect} but runs only a single async operation at a time. + * + * @name detectSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.detect]{@link module:Collections.detect} + * @alias findSeries + * @category Collections + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`. + * The iteratee must complete with a boolean value as its result. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the `iteratee` functions have finished. + * Result will be the first item in the array that passes the truth test + * (iteratee) or the value `undefined` if none passed. Invoked with + * (err, result). + * @returns {Promise} a promise, if a callback is omitted + */ + function detectSeries(coll, iteratee, callback) { + return _createTester(bool => bool, (res, item) => item)(eachOfLimit(1), coll, iteratee, callback) + } + + var detectSeries$1 = awaitify(detectSeries, 3); + + function consoleFunc(name) { + return (fn, ...args) => wrapAsync(fn)(...args, (err, ...resultArgs) => { + /* istanbul ignore else */ + if (typeof console === 'object') { + /* istanbul ignore else */ + if (err) { + /* istanbul ignore else */ + if (console.error) { + console.error(err); + } + } else if (console[name]) { /* istanbul ignore else */ + resultArgs.forEach(x => console[name](x)); + } + } + }) + } + + /** + * Logs the result of an [`async` function]{@link AsyncFunction} to the + * `console` using `console.dir` to display the properties of the resulting object. + * Only works in Node.js or in browsers that support `console.dir` and + * `console.error` (such as FF and Chrome). + * If multiple arguments are returned from the async function, + * `console.dir` is called on each argument in order. + * + * @name dir + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} function - The function you want to eventually apply + * all arguments to. + * @param {...*} arguments... - Any number of arguments to apply to the function. + * @example + * + * // in a module + * var hello = function(name, callback) { + * setTimeout(function() { + * callback(null, {hello: name}); + * }, 1000); + * }; + * + * // in the node repl + * node> async.dir(hello, 'world'); + * {hello: 'world'} + */ + var dir = consoleFunc('dir'); + + /** + * The post-check version of [`whilst`]{@link module:ControlFlow.whilst}. To reflect the difference in + * the order of operations, the arguments `test` and `iteratee` are switched. + * + * `doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript. + * + * @name doWhilst + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.whilst]{@link module:ControlFlow.whilst} + * @category Control Flow + * @param {AsyncFunction} iteratee - A function which is called each time `test` + * passes. Invoked with (callback). + * @param {AsyncFunction} test - asynchronous truth test to perform after each + * execution of `iteratee`. Invoked with (...args, callback), where `...args` are the + * non-error args from the previous callback of `iteratee`. + * @param {Function} [callback] - A callback which is called after the test + * function has failed and repeated execution of `iteratee` has stopped. + * `callback` will be passed an error and any arguments passed to the final + * `iteratee`'s callback. Invoked with (err, [results]); + * @returns {Promise} a promise, if no callback is passed + */ + function doWhilst(iteratee, test, callback) { + callback = onlyOnce(callback); + var _fn = wrapAsync(iteratee); + var _test = wrapAsync(test); + var results; + + function next(err, ...args) { + if (err) return callback(err); + if (err === false) return; + results = args; + _test(...args, check); + } + + function check(err, truth) { + if (err) return callback(err); + if (err === false) return; + if (!truth) return callback(null, ...results); + _fn(next); + } + + return check(null, true); + } + + var doWhilst$1 = awaitify(doWhilst, 3); + + /** + * Like ['doWhilst']{@link module:ControlFlow.doWhilst}, except the `test` is inverted. Note the + * argument ordering differs from `until`. + * + * @name doUntil + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.doWhilst]{@link module:ControlFlow.doWhilst} + * @category Control Flow + * @param {AsyncFunction} iteratee - An async function which is called each time + * `test` fails. Invoked with (callback). + * @param {AsyncFunction} test - asynchronous truth test to perform after each + * execution of `iteratee`. Invoked with (...args, callback), where `...args` are the + * non-error args from the previous callback of `iteratee` + * @param {Function} [callback] - A callback which is called after the test + * function has passed and repeated execution of `iteratee` has stopped. `callback` + * will be passed an error and any arguments passed to the final `iteratee`'s + * callback. Invoked with (err, [results]); + * @returns {Promise} a promise, if no callback is passed + */ + function doUntil(iteratee, test, callback) { + const _test = wrapAsync(test); + return doWhilst$1(iteratee, (...args) => { + const cb = args.pop(); + _test(...args, (err, truth) => cb (err, !truth)); + }, callback); + } + + function _withoutIndex(iteratee) { + return (value, index, callback) => iteratee(value, callback); + } + + /** + * Applies the function `iteratee` to each item in `coll`, in parallel. + * The `iteratee` is called with an item from the list, and a callback for when + * it has finished. If the `iteratee` passes an error to its `callback`, the + * main `callback` (for the `each` function) is immediately called with the + * error. + * + * Note, that since this function applies `iteratee` to each item in parallel, + * there is no guarantee that the iteratee functions will complete in order. + * + * @name each + * @static + * @memberOf module:Collections + * @method + * @alias forEach + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to + * each item in `coll`. Invoked with (item, callback). + * The array index is not passed to the iteratee. + * If you need the index, use `eachOf`. + * @param {Function} [callback] - A callback which is called when all + * `iteratee` functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * // dir4 does not exist + * + * const fileList = [ 'dir1/file2.txt', 'dir2/file3.txt', 'dir/file5.txt']; + * const withMissingFileList = ['dir1/file1.txt', 'dir4/file2.txt']; + * + * // asynchronous function that deletes a file + * const deleteFile = function(file, callback) { + * fs.unlink(file, callback); + * }; + * + * // Using callbacks + * async.each(fileList, deleteFile, function(err) { + * if( err ) { + * console.log(err); + * } else { + * console.log('All files have been deleted successfully'); + * } + * }); + * + * // Error Handling + * async.each(withMissingFileList, deleteFile, function(err){ + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4/file2.txt does not exist + * // dir1/file1.txt could have been deleted + * }); + * + * // Using Promises + * async.each(fileList, deleteFile) + * .then( () => { + * console.log('All files have been deleted successfully'); + * }).catch( err => { + * console.log(err); + * }); + * + * // Error Handling + * async.each(fileList, deleteFile) + * .then( () => { + * console.log('All files have been deleted successfully'); + * }).catch( err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4/file2.txt does not exist + * // dir1/file1.txt could have been deleted + * }); + * + * // Using async/await + * async () => { + * try { + * await async.each(files, deleteFile); + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // Error Handling + * async () => { + * try { + * await async.each(withMissingFileList, deleteFile); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * // since dir4/file2.txt does not exist + * // dir1/file1.txt could have been deleted + * } + * } + * + */ + function eachLimit(coll, iteratee, callback) { + return eachOf$1(coll, _withoutIndex(wrapAsync(iteratee)), callback); + } + + var each = awaitify(eachLimit, 3); + + /** + * The same as [`each`]{@link module:Collections.each} but runs a maximum of `limit` async operations at a time. + * + * @name eachLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.each]{@link module:Collections.each} + * @alias forEachLimit + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The array index is not passed to the iteratee. + * If you need the index, use `eachOfLimit`. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called when all + * `iteratee` functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + */ + function eachLimit$1(coll, limit, iteratee, callback) { + return eachOfLimit(limit)(coll, _withoutIndex(wrapAsync(iteratee)), callback); + } + var eachLimit$2 = awaitify(eachLimit$1, 4); + + /** + * The same as [`each`]{@link module:Collections.each} but runs only a single async operation at a time. + * + * Note, that unlike [`each`]{@link module:Collections.each}, this function applies iteratee to each item + * in series and therefore the iteratee functions will complete in order. + + * @name eachSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.each]{@link module:Collections.each} + * @alias forEachSeries + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each + * item in `coll`. + * The array index is not passed to the iteratee. + * If you need the index, use `eachOfSeries`. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called when all + * `iteratee` functions have finished, or an error occurs. Invoked with (err). + * @returns {Promise} a promise, if a callback is omitted + */ + function eachSeries(coll, iteratee, callback) { + return eachLimit$2(coll, 1, iteratee, callback) + } + var eachSeries$1 = awaitify(eachSeries, 3); + + /** + * Wrap an async function and ensure it calls its callback on a later tick of + * the event loop. If the function already calls its callback on a next tick, + * no extra deferral is added. This is useful for preventing stack overflows + * (`RangeError: Maximum call stack size exceeded`) and generally keeping + * [Zalgo](http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony) + * contained. ES2017 `async` functions are returned as-is -- they are immune + * to Zalgo's corrupting influences, as they always resolve on a later tick. + * + * @name ensureAsync + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} fn - an async function, one that expects a node-style + * callback as its last argument. + * @returns {AsyncFunction} Returns a wrapped function with the exact same call + * signature as the function passed in. + * @example + * + * function sometimesAsync(arg, callback) { + * if (cache[arg]) { + * return callback(null, cache[arg]); // this would be synchronous!! + * } else { + * doSomeIO(arg, callback); // this IO would be asynchronous + * } + * } + * + * // this has a risk of stack overflows if many results are cached in a row + * async.mapSeries(args, sometimesAsync, done); + * + * // this will defer sometimesAsync's callback if necessary, + * // preventing stack overflows + * async.mapSeries(args, async.ensureAsync(sometimesAsync), done); + */ + function ensureAsync(fn) { + if (isAsync(fn)) return fn; + return function (...args/*, callback*/) { + var callback = args.pop(); + var sync = true; + args.push((...innerArgs) => { + if (sync) { + setImmediate$1(() => callback(...innerArgs)); + } else { + callback(...innerArgs); + } + }); + fn.apply(this, args); + sync = false; + }; + } + + /** + * Returns `true` if every element in `coll` satisfies an async test. If any + * iteratee call returns `false`, the main `callback` is immediately called. + * + * @name every + * @static + * @memberOf module:Collections + * @method + * @alias all + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collection in parallel. + * The iteratee must complete with a boolean result value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result will be either `true` or `false` + * depending on the values of the async tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * // dir4 does not exist + * + * const fileList = ['dir1/file1.txt','dir2/file3.txt','dir3/file5.txt']; + * const withMissingFileList = ['file1.txt','file2.txt','file4.txt']; + * + * // asynchronous function that checks if a file exists + * function fileExists(file, callback) { + * fs.access(file, fs.constants.F_OK, (err) => { + * callback(null, !err); + * }); + * } + * + * // Using callbacks + * async.every(fileList, fileExists, function(err, result) { + * console.log(result); + * // true + * // result is true since every file exists + * }); + * + * async.every(withMissingFileList, fileExists, function(err, result) { + * console.log(result); + * // false + * // result is false since NOT every file exists + * }); + * + * // Using Promises + * async.every(fileList, fileExists) + * .then( result => { + * console.log(result); + * // true + * // result is true since every file exists + * }).catch( err => { + * console.log(err); + * }); + * + * async.every(withMissingFileList, fileExists) + * .then( result => { + * console.log(result); + * // false + * // result is false since NOT every file exists + * }).catch( err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.every(fileList, fileExists); + * console.log(result); + * // true + * // result is true since every file exists + * } + * catch (err) { + * console.log(err); + * } + * } + * + * async () => { + * try { + * let result = await async.every(withMissingFileList, fileExists); + * console.log(result); + * // false + * // result is false since NOT every file exists + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function every(coll, iteratee, callback) { + return _createTester(bool => !bool, res => !res)(eachOf$1, coll, iteratee, callback) + } + var every$1 = awaitify(every, 3); + + /** + * The same as [`every`]{@link module:Collections.every} but runs a maximum of `limit` async operations at a time. + * + * @name everyLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.every]{@link module:Collections.every} + * @alias allLimit + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collection in parallel. + * The iteratee must complete with a boolean result value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result will be either `true` or `false` + * depending on the values of the async tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + */ + function everyLimit(coll, limit, iteratee, callback) { + return _createTester(bool => !bool, res => !res)(eachOfLimit(limit), coll, iteratee, callback) + } + var everyLimit$1 = awaitify(everyLimit, 4); + + /** + * The same as [`every`]{@link module:Collections.every} but runs only a single async operation at a time. + * + * @name everySeries + * @static + * @memberOf module:Collections + * @method + * @see [async.every]{@link module:Collections.every} + * @alias allSeries + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collection in series. + * The iteratee must complete with a boolean result value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result will be either `true` or `false` + * depending on the values of the async tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + */ + function everySeries(coll, iteratee, callback) { + return _createTester(bool => !bool, res => !res)(eachOfSeries$1, coll, iteratee, callback) + } + var everySeries$1 = awaitify(everySeries, 3); + + function filterArray(eachfn, arr, iteratee, callback) { + var truthValues = new Array(arr.length); + eachfn(arr, (x, index, iterCb) => { + iteratee(x, (err, v) => { + truthValues[index] = !!v; + iterCb(err); + }); + }, err => { + if (err) return callback(err); + var results = []; + for (var i = 0; i < arr.length; i++) { + if (truthValues[i]) results.push(arr[i]); + } + callback(null, results); + }); + } + + function filterGeneric(eachfn, coll, iteratee, callback) { + var results = []; + eachfn(coll, (x, index, iterCb) => { + iteratee(x, (err, v) => { + if (err) return iterCb(err); + if (v) { + results.push({index, value: x}); + } + iterCb(err); + }); + }, err => { + if (err) return callback(err); + callback(null, results + .sort((a, b) => a.index - b.index) + .map(v => v.value)); + }); + } + + function _filter(eachfn, coll, iteratee, callback) { + var filter = isArrayLike(coll) ? filterArray : filterGeneric; + return filter(eachfn, coll, wrapAsync(iteratee), callback); + } + + /** + * Returns a new array of all the values in `coll` which pass an async truth + * test. This operation is performed in parallel, but the results array will be + * in the same order as the original. + * + * @name filter + * @static + * @memberOf module:Collections + * @method + * @alias select + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {Function} iteratee - A truth test to apply to each item in `coll`. + * The `iteratee` is passed a `callback(err, truthValue)`, which must be called + * with a boolean argument once it has completed. Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results). + * @returns {Promise} a promise, if no callback provided + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * + * const files = ['dir1/file1.txt','dir2/file3.txt','dir3/file6.txt']; + * + * // asynchronous function that checks if a file exists + * function fileExists(file, callback) { + * fs.access(file, fs.constants.F_OK, (err) => { + * callback(null, !err); + * }); + * } + * + * // Using callbacks + * async.filter(files, fileExists, function(err, results) { + * if(err) { + * console.log(err); + * } else { + * console.log(results); + * // [ 'dir1/file1.txt', 'dir2/file3.txt' ] + * // results is now an array of the existing files + * } + * }); + * + * // Using Promises + * async.filter(files, fileExists) + * .then(results => { + * console.log(results); + * // [ 'dir1/file1.txt', 'dir2/file3.txt' ] + * // results is now an array of the existing files + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let results = await async.filter(files, fileExists); + * console.log(results); + * // [ 'dir1/file1.txt', 'dir2/file3.txt' ] + * // results is now an array of the existing files + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function filter (coll, iteratee, callback) { + return _filter(eachOf$1, coll, iteratee, callback) + } + var filter$1 = awaitify(filter, 3); + + /** + * The same as [`filter`]{@link module:Collections.filter} but runs a maximum of `limit` async operations at a + * time. + * + * @name filterLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.filter]{@link module:Collections.filter} + * @alias selectLimit + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {Function} iteratee - A truth test to apply to each item in `coll`. + * The `iteratee` is passed a `callback(err, truthValue)`, which must be called + * with a boolean argument once it has completed. Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results). + * @returns {Promise} a promise, if no callback provided + */ + function filterLimit (coll, limit, iteratee, callback) { + return _filter(eachOfLimit(limit), coll, iteratee, callback) + } + var filterLimit$1 = awaitify(filterLimit, 4); + + /** + * The same as [`filter`]{@link module:Collections.filter} but runs only a single async operation at a time. + * + * @name filterSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.filter]{@link module:Collections.filter} + * @alias selectSeries + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {Function} iteratee - A truth test to apply to each item in `coll`. + * The `iteratee` is passed a `callback(err, truthValue)`, which must be called + * with a boolean argument once it has completed. Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results) + * @returns {Promise} a promise, if no callback provided + */ + function filterSeries (coll, iteratee, callback) { + return _filter(eachOfSeries$1, coll, iteratee, callback) + } + var filterSeries$1 = awaitify(filterSeries, 3); + + /** + * Calls the asynchronous function `fn` with a callback parameter that allows it + * to call itself again, in series, indefinitely. + + * If an error is passed to the callback then `errback` is called with the + * error, and execution stops, otherwise it will never be called. + * + * @name forever + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {AsyncFunction} fn - an async function to call repeatedly. + * Invoked with (next). + * @param {Function} [errback] - when `fn` passes an error to it's callback, + * this function will be called, and execution stops. Invoked with (err). + * @returns {Promise} a promise that rejects if an error occurs and an errback + * is not passed + * @example + * + * async.forever( + * function(next) { + * // next is suitable for passing to things that need a callback(err [, whatever]); + * // it will result in this function being called again. + * }, + * function(err) { + * // if next is called with a value in its first parameter, it will appear + * // in here as 'err', and execution will stop. + * } + * ); + */ + function forever(fn, errback) { + var done = onlyOnce(errback); + var task = wrapAsync(ensureAsync(fn)); + + function next(err) { + if (err) return done(err); + if (err === false) return; + task(next); + } + return next(); + } + var forever$1 = awaitify(forever, 2); + + /** + * The same as [`groupBy`]{@link module:Collections.groupBy} but runs a maximum of `limit` async operations at a time. + * + * @name groupByLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.groupBy]{@link module:Collections.groupBy} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with a `key` to group the value under. + * Invoked with (value, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Result is an `Object` whoses + * properties are arrays of values which returned the corresponding key. + * @returns {Promise} a promise, if no callback is passed + */ + function groupByLimit(coll, limit, iteratee, callback) { + var _iteratee = wrapAsync(iteratee); + return mapLimit$1(coll, limit, (val, iterCb) => { + _iteratee(val, (err, key) => { + if (err) return iterCb(err); + return iterCb(err, {key, val}); + }); + }, (err, mapResults) => { + var result = {}; + // from MDN, handle object having an `hasOwnProperty` prop + var {hasOwnProperty} = Object.prototype; + + for (var i = 0; i < mapResults.length; i++) { + if (mapResults[i]) { + var {key} = mapResults[i]; + var {val} = mapResults[i]; + + if (hasOwnProperty.call(result, key)) { + result[key].push(val); + } else { + result[key] = [val]; + } + } + } + + return callback(err, result); + }); + } + + var groupByLimit$1 = awaitify(groupByLimit, 4); + + /** + * Returns a new object, where each value corresponds to an array of items, from + * `coll`, that returned the corresponding key. That is, the keys of the object + * correspond to the values passed to the `iteratee` callback. + * + * Note: Since this function applies the `iteratee` to each item in parallel, + * there is no guarantee that the `iteratee` functions will complete in order. + * However, the values for each key in the `result` will be in the same order as + * the original `coll`. For Objects, the values will roughly be in the order of + * the original Objects' keys (but this can vary across JavaScript engines). + * + * @name groupBy + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with a `key` to group the value under. + * Invoked with (value, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Result is an `Object` whoses + * properties are arrays of values which returned the corresponding key. + * @returns {Promise} a promise, if no callback is passed + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * // dir4 does not exist + * + * const files = ['dir1/file1.txt','dir2','dir4'] + * + * // asynchronous function that detects file type as none, file, or directory + * function detectFile(file, callback) { + * fs.stat(file, function(err, stat) { + * if (err) { + * return callback(null, 'none'); + * } + * callback(null, stat.isDirectory() ? 'directory' : 'file'); + * }); + * } + * + * //Using callbacks + * async.groupBy(files, detectFile, function(err, result) { + * if(err) { + * console.log(err); + * } else { + * console.log(result); + * // { + * // file: [ 'dir1/file1.txt' ], + * // none: [ 'dir4' ], + * // directory: [ 'dir2'] + * // } + * // result is object containing the files grouped by type + * } + * }); + * + * // Using Promises + * async.groupBy(files, detectFile) + * .then( result => { + * console.log(result); + * // { + * // file: [ 'dir1/file1.txt' ], + * // none: [ 'dir4' ], + * // directory: [ 'dir2'] + * // } + * // result is object containing the files grouped by type + * }).catch( err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.groupBy(files, detectFile); + * console.log(result); + * // { + * // file: [ 'dir1/file1.txt' ], + * // none: [ 'dir4' ], + * // directory: [ 'dir2'] + * // } + * // result is object containing the files grouped by type + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function groupBy (coll, iteratee, callback) { + return groupByLimit$1(coll, Infinity, iteratee, callback) + } + + /** + * The same as [`groupBy`]{@link module:Collections.groupBy} but runs only a single async operation at a time. + * + * @name groupBySeries + * @static + * @memberOf module:Collections + * @method + * @see [async.groupBy]{@link module:Collections.groupBy} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with a `key` to group the value under. + * Invoked with (value, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. Result is an `Object` whose + * properties are arrays of values which returned the corresponding key. + * @returns {Promise} a promise, if no callback is passed + */ + function groupBySeries (coll, iteratee, callback) { + return groupByLimit$1(coll, 1, iteratee, callback) + } + + /** + * Logs the result of an `async` function to the `console`. Only works in + * Node.js or in browsers that support `console.log` and `console.error` (such + * as FF and Chrome). If multiple arguments are returned from the async + * function, `console.log` is called on each argument in order. + * + * @name log + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} function - The function you want to eventually apply + * all arguments to. + * @param {...*} arguments... - Any number of arguments to apply to the function. + * @example + * + * // in a module + * var hello = function(name, callback) { + * setTimeout(function() { + * callback(null, 'hello ' + name); + * }, 1000); + * }; + * + * // in the node repl + * node> async.log(hello, 'world'); + * 'hello world' + */ + var log = consoleFunc('log'); + + /** + * The same as [`mapValues`]{@link module:Collections.mapValues} but runs a maximum of `limit` async operations at a + * time. + * + * @name mapValuesLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.mapValues]{@link module:Collections.mapValues} + * @category Collection + * @param {Object} obj - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - A function to apply to each value and key + * in `coll`. + * The iteratee should complete with the transformed value as its result. + * Invoked with (value, key, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. `result` is a new object consisting + * of each key from `obj`, with each transformed value on the right-hand side. + * Invoked with (err, result). + * @returns {Promise} a promise, if no callback is passed + */ + function mapValuesLimit(obj, limit, iteratee, callback) { + callback = once(callback); + var newObj = {}; + var _iteratee = wrapAsync(iteratee); + return eachOfLimit(limit)(obj, (val, key, next) => { + _iteratee(val, key, (err, result) => { + if (err) return next(err); + newObj[key] = result; + next(err); + }); + }, err => callback(err, newObj)); + } + + var mapValuesLimit$1 = awaitify(mapValuesLimit, 4); + + /** + * A relative of [`map`]{@link module:Collections.map}, designed for use with objects. + * + * Produces a new Object by mapping each value of `obj` through the `iteratee` + * function. The `iteratee` is called each `value` and `key` from `obj` and a + * callback for when it has finished processing. Each of these callbacks takes + * two arguments: an `error`, and the transformed item from `obj`. If `iteratee` + * passes an error to its callback, the main `callback` (for the `mapValues` + * function) is immediately called with the error. + * + * Note, the order of the keys in the result is not guaranteed. The keys will + * be roughly in the order they complete, (but this is very engine-specific) + * + * @name mapValues + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Object} obj - A collection to iterate over. + * @param {AsyncFunction} iteratee - A function to apply to each value and key + * in `coll`. + * The iteratee should complete with the transformed value as its result. + * Invoked with (value, key, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. `result` is a new object consisting + * of each key from `obj`, with each transformed value on the right-hand side. + * Invoked with (err, result). + * @returns {Promise} a promise, if no callback is passed + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * // file4.txt does not exist + * + * const fileMap = { + * f1: 'file1.txt', + * f2: 'file2.txt', + * f3: 'file3.txt' + * }; + * + * const withMissingFileMap = { + * f1: 'file1.txt', + * f2: 'file2.txt', + * f3: 'file4.txt' + * }; + * + * // asynchronous function that returns the file size in bytes + * function getFileSizeInBytes(file, key, callback) { + * fs.stat(file, function(err, stat) { + * if (err) { + * return callback(err); + * } + * callback(null, stat.size); + * }); + * } + * + * // Using callbacks + * async.mapValues(fileMap, getFileSizeInBytes, function(err, result) { + * if (err) { + * console.log(err); + * } else { + * console.log(result); + * // result is now a map of file size in bytes for each file, e.g. + * // { + * // f1: 1000, + * // f2: 2000, + * // f3: 3000 + * // } + * } + * }); + * + * // Error handling + * async.mapValues(withMissingFileMap, getFileSizeInBytes, function(err, result) { + * if (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } else { + * console.log(result); + * } + * }); + * + * // Using Promises + * async.mapValues(fileMap, getFileSizeInBytes) + * .then( result => { + * console.log(result); + * // result is now a map of file size in bytes for each file, e.g. + * // { + * // f1: 1000, + * // f2: 2000, + * // f3: 3000 + * // } + * }).catch (err => { + * console.log(err); + * }); + * + * // Error Handling + * async.mapValues(withMissingFileMap, getFileSizeInBytes) + * .then( result => { + * console.log(result); + * }).catch (err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.mapValues(fileMap, getFileSizeInBytes); + * console.log(result); + * // result is now a map of file size in bytes for each file, e.g. + * // { + * // f1: 1000, + * // f2: 2000, + * // f3: 3000 + * // } + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // Error Handling + * async () => { + * try { + * let result = await async.mapValues(withMissingFileMap, getFileSizeInBytes); + * console.log(result); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } + * } + * + */ + function mapValues(obj, iteratee, callback) { + return mapValuesLimit$1(obj, Infinity, iteratee, callback) + } + + /** + * The same as [`mapValues`]{@link module:Collections.mapValues} but runs only a single async operation at a time. + * + * @name mapValuesSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.mapValues]{@link module:Collections.mapValues} + * @category Collection + * @param {Object} obj - A collection to iterate over. + * @param {AsyncFunction} iteratee - A function to apply to each value and key + * in `coll`. + * The iteratee should complete with the transformed value as its result. + * Invoked with (value, key, callback). + * @param {Function} [callback] - A callback which is called when all `iteratee` + * functions have finished, or an error occurs. `result` is a new object consisting + * of each key from `obj`, with each transformed value on the right-hand side. + * Invoked with (err, result). + * @returns {Promise} a promise, if no callback is passed + */ + function mapValuesSeries(obj, iteratee, callback) { + return mapValuesLimit$1(obj, 1, iteratee, callback) + } + + /** + * Caches the results of an async function. When creating a hash to store + * function results against, the callback is omitted from the hash and an + * optional hash function can be used. + * + * **Note: if the async function errs, the result will not be cached and + * subsequent calls will call the wrapped function.** + * + * If no hash function is specified, the first argument is used as a hash key, + * which may work reasonably if it is a string or a data type that converts to a + * distinct string. Note that objects and arrays will not behave reasonably. + * Neither will cases where the other arguments are significant. In such cases, + * specify your own hash function. + * + * The cache of results is exposed as the `memo` property of the function + * returned by `memoize`. + * + * @name memoize + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} fn - The async function to proxy and cache results from. + * @param {Function} hasher - An optional function for generating a custom hash + * for storing results. It has all the arguments applied to it apart from the + * callback, and must be synchronous. + * @returns {AsyncFunction} a memoized version of `fn` + * @example + * + * var slow_fn = function(name, callback) { + * // do something + * callback(null, result); + * }; + * var fn = async.memoize(slow_fn); + * + * // fn can now be used as if it were slow_fn + * fn('some name', function() { + * // callback + * }); + */ + function memoize(fn, hasher = v => v) { + var memo = Object.create(null); + var queues = Object.create(null); + var _fn = wrapAsync(fn); + var memoized = initialParams((args, callback) => { + var key = hasher(...args); + if (key in memo) { + setImmediate$1(() => callback(null, ...memo[key])); + } else if (key in queues) { + queues[key].push(callback); + } else { + queues[key] = [callback]; + _fn(...args, (err, ...resultArgs) => { + // #1465 don't memoize if an error occurred + if (!err) { + memo[key] = resultArgs; + } + var q = queues[key]; + delete queues[key]; + for (var i = 0, l = q.length; i < l; i++) { + q[i](err, ...resultArgs); + } + }); + } + }); + memoized.memo = memo; + memoized.unmemoized = fn; + return memoized; + } + + /* istanbul ignore file */ + + /** + * Calls `callback` on a later loop around the event loop. In Node.js this just + * calls `process.nextTick`. In the browser it will use `setImmediate` if + * available, otherwise `setTimeout(callback, 0)`, which means other higher + * priority events may precede the execution of `callback`. + * + * This is used internally for browser-compatibility purposes. + * + * @name nextTick + * @static + * @memberOf module:Utils + * @method + * @see [async.setImmediate]{@link module:Utils.setImmediate} + * @category Util + * @param {Function} callback - The function to call on a later loop around + * the event loop. Invoked with (args...). + * @param {...*} args... - any number of additional arguments to pass to the + * callback on the next tick. + * @example + * + * var call_order = []; + * async.nextTick(function() { + * call_order.push('two'); + * // call_order now equals ['one','two'] + * }); + * call_order.push('one'); + * + * async.setImmediate(function (a, b, c) { + * // a, b, and c equal 1, 2, and 3 + * }, 1, 2, 3); + */ + var _defer$1; + + if (hasNextTick) { + _defer$1 = process.nextTick; + } else if (hasSetImmediate) { + _defer$1 = setImmediate; + } else { + _defer$1 = fallback; + } + + var nextTick = wrap(_defer$1); + + var parallel = awaitify((eachfn, tasks, callback) => { + var results = isArrayLike(tasks) ? [] : {}; + + eachfn(tasks, (task, key, taskCb) => { + wrapAsync(task)((err, ...result) => { + if (result.length < 2) { + [result] = result; + } + results[key] = result; + taskCb(err); + }); + }, err => callback(err, results)); + }, 3); + + /** + * Run the `tasks` collection of functions in parallel, without waiting until + * the previous function has completed. If any of the functions pass an error to + * its callback, the main `callback` is immediately called with the value of the + * error. Once the `tasks` have completed, the results are passed to the final + * `callback` as an array. + * + * **Note:** `parallel` is about kicking-off I/O tasks in parallel, not about + * parallel execution of code. If your tasks do not use any timers or perform + * any I/O, they will actually be executed in series. Any synchronous setup + * sections for each task will happen one after the other. JavaScript remains + * single-threaded. + * + * **Hint:** Use [`reflect`]{@link module:Utils.reflect} to continue the + * execution of other tasks when a task fails. + * + * It is also possible to use an object instead of an array. Each property will + * be run as a function and the results will be passed to the final `callback` + * as an object instead of an array. This can be a more readable way of handling + * results from {@link async.parallel}. + * + * @name parallel + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection of + * [async functions]{@link AsyncFunction} to run. + * Each async function can complete with any number of optional `result` values. + * @param {Function} [callback] - An optional callback to run once all the + * functions have completed successfully. This function gets a results array + * (or object) containing all the result arguments passed to the task callbacks. + * Invoked with (err, results). + * @returns {Promise} a promise, if a callback is not passed + * + * @example + * + * //Using Callbacks + * async.parallel([ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ], function(err, results) { + * console.log(results); + * // results is equal to ['one','two'] even though + * // the second function had a shorter timeout. + * }); + * + * // an example using an object instead of an array + * async.parallel({ + * one: function(callback) { + * setTimeout(function() { + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * callback(null, 2); + * }, 100); + * } + * }, function(err, results) { + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * }); + * + * //Using Promises + * async.parallel([ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ]).then(results => { + * console.log(results); + * // results is equal to ['one','two'] even though + * // the second function had a shorter timeout. + * }).catch(err => { + * console.log(err); + * }); + * + * // an example using an object instead of an array + * async.parallel({ + * one: function(callback) { + * setTimeout(function() { + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * callback(null, 2); + * }, 100); + * } + * }).then(results => { + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * }).catch(err => { + * console.log(err); + * }); + * + * //Using async/await + * async () => { + * try { + * let results = await async.parallel([ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ]); + * console.log(results); + * // results is equal to ['one','two'] even though + * // the second function had a shorter timeout. + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // an example using an object instead of an array + * async () => { + * try { + * let results = await async.parallel({ + * one: function(callback) { + * setTimeout(function() { + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * callback(null, 2); + * }, 100); + * } + * }); + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function parallel$1(tasks, callback) { + return parallel(eachOf$1, tasks, callback); + } + + /** + * The same as [`parallel`]{@link module:ControlFlow.parallel} but runs a maximum of `limit` async operations at a + * time. + * + * @name parallelLimit + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.parallel]{@link module:ControlFlow.parallel} + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection of + * [async functions]{@link AsyncFunction} to run. + * Each async function can complete with any number of optional `result` values. + * @param {number} limit - The maximum number of async operations at a time. + * @param {Function} [callback] - An optional callback to run once all the + * functions have completed successfully. This function gets a results array + * (or object) containing all the result arguments passed to the task callbacks. + * Invoked with (err, results). + * @returns {Promise} a promise, if a callback is not passed + */ + function parallelLimit(tasks, limit, callback) { + return parallel(eachOfLimit(limit), tasks, callback); + } + + /** + * A queue of tasks for the worker function to complete. + * @typedef {Iterable} QueueObject + * @memberOf module:ControlFlow + * @property {Function} length - a function returning the number of items + * waiting to be processed. Invoke with `queue.length()`. + * @property {boolean} started - a boolean indicating whether or not any + * items have been pushed and processed by the queue. + * @property {Function} running - a function returning the number of items + * currently being processed. Invoke with `queue.running()`. + * @property {Function} workersList - a function returning the array of items + * currently being processed. Invoke with `queue.workersList()`. + * @property {Function} idle - a function returning false if there are items + * waiting or being processed, or true if not. Invoke with `queue.idle()`. + * @property {number} concurrency - an integer for determining how many `worker` + * functions should be run in parallel. This property can be changed after a + * `queue` is created to alter the concurrency on-the-fly. + * @property {number} payload - an integer that specifies how many items are + * passed to the worker function at a time. only applies if this is a + * [cargo]{@link module:ControlFlow.cargo} object + * @property {AsyncFunction} push - add a new task to the `queue`. Calls `callback` + * once the `worker` has finished processing the task. Instead of a single task, + * a `tasks` array can be submitted. The respective callback is used for every + * task in the list. Invoke with `queue.push(task, [callback])`, + * @property {AsyncFunction} unshift - add a new task to the front of the `queue`. + * Invoke with `queue.unshift(task, [callback])`. + * @property {AsyncFunction} pushAsync - the same as `q.push`, except this returns + * a promise that rejects if an error occurs. + * @property {AsyncFunction} unshiftAsync - the same as `q.unshift`, except this returns + * a promise that rejects if an error occurs. + * @property {Function} remove - remove items from the queue that match a test + * function. The test function will be passed an object with a `data` property, + * and a `priority` property, if this is a + * [priorityQueue]{@link module:ControlFlow.priorityQueue} object. + * Invoked with `queue.remove(testFn)`, where `testFn` is of the form + * `function ({data, priority}) {}` and returns a Boolean. + * @property {Function} saturated - a function that sets a callback that is + * called when the number of running workers hits the `concurrency` limit, and + * further tasks will be queued. If the callback is omitted, `q.saturated()` + * returns a promise for the next occurrence. + * @property {Function} unsaturated - a function that sets a callback that is + * called when the number of running workers is less than the `concurrency` & + * `buffer` limits, and further tasks will not be queued. If the callback is + * omitted, `q.unsaturated()` returns a promise for the next occurrence. + * @property {number} buffer - A minimum threshold buffer in order to say that + * the `queue` is `unsaturated`. + * @property {Function} empty - a function that sets a callback that is called + * when the last item from the `queue` is given to a `worker`. If the callback + * is omitted, `q.empty()` returns a promise for the next occurrence. + * @property {Function} drain - a function that sets a callback that is called + * when the last item from the `queue` has returned from the `worker`. If the + * callback is omitted, `q.drain()` returns a promise for the next occurrence. + * @property {Function} error - a function that sets a callback that is called + * when a task errors. Has the signature `function(error, task)`. If the + * callback is omitted, `error()` returns a promise that rejects on the next + * error. + * @property {boolean} paused - a boolean for determining whether the queue is + * in a paused state. + * @property {Function} pause - a function that pauses the processing of tasks + * until `resume()` is called. Invoke with `queue.pause()`. + * @property {Function} resume - a function that resumes the processing of + * queued tasks when the queue is paused. Invoke with `queue.resume()`. + * @property {Function} kill - a function that removes the `drain` callback and + * empties remaining tasks from the queue forcing it to go idle. No more tasks + * should be pushed to the queue after calling this function. Invoke with `queue.kill()`. + * + * @example + * const q = async.queue(worker, 2) + * q.push(item1) + * q.push(item2) + * q.push(item3) + * // queues are iterable, spread into an array to inspect + * const items = [...q] // [item1, item2, item3] + * // or use for of + * for (let item of q) { + * console.log(item) + * } + * + * q.drain(() => { + * console.log('all done') + * }) + * // or + * await q.drain() + */ + + /** + * Creates a `queue` object with the specified `concurrency`. Tasks added to the + * `queue` are processed in parallel (up to the `concurrency` limit). If all + * `worker`s are in progress, the task is queued until one becomes available. + * Once a `worker` completes a `task`, that `task`'s callback is called. + * + * @name queue + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {AsyncFunction} worker - An async function for processing a queued task. + * If you want to handle errors from an individual task, pass a callback to + * `q.push()`. Invoked with (task, callback). + * @param {number} [concurrency=1] - An `integer` for determining how many + * `worker` functions should be run in parallel. If omitted, the concurrency + * defaults to `1`. If the concurrency is `0`, an error is thrown. + * @returns {module:ControlFlow.QueueObject} A queue object to manage the tasks. Callbacks can be + * attached as certain properties to listen for specific events during the + * lifecycle of the queue. + * @example + * + * // create a queue object with concurrency 2 + * var q = async.queue(function(task, callback) { + * console.log('hello ' + task.name); + * callback(); + * }, 2); + * + * // assign a callback + * q.drain(function() { + * console.log('all items have been processed'); + * }); + * // or await the end + * await q.drain() + * + * // assign an error callback + * q.error(function(err, task) { + * console.error('task experienced an error'); + * }); + * + * // add some items to the queue + * q.push({name: 'foo'}, function(err) { + * console.log('finished processing foo'); + * }); + * // callback is optional + * q.push({name: 'bar'}); + * + * // add some items to the queue (batch-wise) + * q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], function(err) { + * console.log('finished processing item'); + * }); + * + * // add some items to the front of the queue + * q.unshift({name: 'bar'}, function (err) { + * console.log('finished processing bar'); + * }); + */ + function queue$1 (worker, concurrency) { + var _worker = wrapAsync(worker); + return queue((items, cb) => { + _worker(items[0], cb); + }, concurrency, 1); + } + + // Binary min-heap implementation used for priority queue. + // Implementation is stable, i.e. push time is considered for equal priorities + class Heap { + constructor() { + this.heap = []; + this.pushCount = Number.MIN_SAFE_INTEGER; + } + + get length() { + return this.heap.length; + } + + empty () { + this.heap = []; + return this; + } + + percUp(index) { + let p; + + while (index > 0 && smaller(this.heap[index], this.heap[p=parent(index)])) { + let t = this.heap[index]; + this.heap[index] = this.heap[p]; + this.heap[p] = t; + + index = p; + } + } + + percDown(index) { + let l; + + while ((l=leftChi(index)) < this.heap.length) { + if (l+1 < this.heap.length && smaller(this.heap[l+1], this.heap[l])) { + l = l+1; + } + + if (smaller(this.heap[index], this.heap[l])) { + break; + } + + let t = this.heap[index]; + this.heap[index] = this.heap[l]; + this.heap[l] = t; + + index = l; + } + } + + push(node) { + node.pushCount = ++this.pushCount; + this.heap.push(node); + this.percUp(this.heap.length-1); + } + + unshift(node) { + return this.heap.push(node); + } + + shift() { + let [top] = this.heap; + + this.heap[0] = this.heap[this.heap.length-1]; + this.heap.pop(); + this.percDown(0); + + return top; + } + + toArray() { + return [...this]; + } + + *[Symbol.iterator] () { + for (let i = 0; i < this.heap.length; i++) { + yield this.heap[i].data; + } + } + + remove (testFn) { + let j = 0; + for (let i = 0; i < this.heap.length; i++) { + if (!testFn(this.heap[i])) { + this.heap[j] = this.heap[i]; + j++; + } + } + + this.heap.splice(j); + + for (let i = parent(this.heap.length-1); i >= 0; i--) { + this.percDown(i); + } + + return this; + } + } + + function leftChi(i) { + return (i<<1)+1; + } + + function parent(i) { + return ((i+1)>>1)-1; + } + + function smaller(x, y) { + if (x.priority !== y.priority) { + return x.priority < y.priority; + } + else { + return x.pushCount < y.pushCount; + } + } + + /** + * The same as [async.queue]{@link module:ControlFlow.queue} only tasks are assigned a priority and + * completed in ascending priority order. + * + * @name priorityQueue + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.queue]{@link module:ControlFlow.queue} + * @category Control Flow + * @param {AsyncFunction} worker - An async function for processing a queued task. + * If you want to handle errors from an individual task, pass a callback to + * `q.push()`. + * Invoked with (task, callback). + * @param {number} concurrency - An `integer` for determining how many `worker` + * functions should be run in parallel. If omitted, the concurrency defaults to + * `1`. If the concurrency is `0`, an error is thrown. + * @returns {module:ControlFlow.QueueObject} A priorityQueue object to manage the tasks. There are three + * differences between `queue` and `priorityQueue` objects: + * * `push(task, priority, [callback])` - `priority` should be a number. If an + * array of `tasks` is given, all tasks will be assigned the same priority. + * * `pushAsync(task, priority, [callback])` - the same as `priorityQueue.push`, + * except this returns a promise that rejects if an error occurs. + * * The `unshift` and `unshiftAsync` methods were removed. + */ + function priorityQueue(worker, concurrency) { + // Start with a normal queue + var q = queue$1(worker, concurrency); + + var { + push, + pushAsync + } = q; + + q._tasks = new Heap(); + q._createTaskItem = ({data, priority}, callback) => { + return { + data, + priority, + callback + }; + }; + + function createDataItems(tasks, priority) { + if (!Array.isArray(tasks)) { + return {data: tasks, priority}; + } + return tasks.map(data => { return {data, priority}; }); + } + + // Override push to accept second parameter representing priority + q.push = function(data, priority = 0, callback) { + return push(createDataItems(data, priority), callback); + }; + + q.pushAsync = function(data, priority = 0, callback) { + return pushAsync(createDataItems(data, priority), callback); + }; + + // Remove unshift functions + delete q.unshift; + delete q.unshiftAsync; + + return q; + } + + /** + * Runs the `tasks` array of functions in parallel, without waiting until the + * previous function has completed. Once any of the `tasks` complete or pass an + * error to its callback, the main `callback` is immediately called. It's + * equivalent to `Promise.race()`. + * + * @name race + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array} tasks - An array containing [async functions]{@link AsyncFunction} + * to run. Each function can complete with an optional `result` value. + * @param {Function} callback - A callback to run once any of the functions have + * completed. This function gets an error or result from the first function that + * completed. Invoked with (err, result). + * @returns {Promise} a promise, if a callback is omitted + * @example + * + * async.race([ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ], + * // main callback + * function(err, result) { + * // the result will be equal to 'two' as it finishes earlier + * }); + */ + function race(tasks, callback) { + callback = once(callback); + if (!Array.isArray(tasks)) return callback(new TypeError('First argument to race must be an array of functions')); + if (!tasks.length) return callback(); + for (var i = 0, l = tasks.length; i < l; i++) { + wrapAsync(tasks[i])(callback); + } + } + + var race$1 = awaitify(race, 2); + + /** + * Same as [`reduce`]{@link module:Collections.reduce}, only operates on `array` in reverse order. + * + * @name reduceRight + * @static + * @memberOf module:Collections + * @method + * @see [async.reduce]{@link module:Collections.reduce} + * @alias foldr + * @category Collection + * @param {Array} array - A collection to iterate over. + * @param {*} memo - The initial state of the reduction. + * @param {AsyncFunction} iteratee - A function applied to each item in the + * array to produce the next step in the reduction. + * The `iteratee` should complete with the next state of the reduction. + * If the iteratee completes with an error, the reduction is stopped and the + * main `callback` is immediately called with the error. + * Invoked with (memo, item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result is the reduced value. Invoked with + * (err, result). + * @returns {Promise} a promise, if no callback is passed + */ + function reduceRight (array, memo, iteratee, callback) { + var reversed = [...array].reverse(); + return reduce$1(reversed, memo, iteratee, callback); + } + + /** + * Wraps the async function in another function that always completes with a + * result object, even when it errors. + * + * The result object has either the property `error` or `value`. + * + * @name reflect + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} fn - The async function you want to wrap + * @returns {Function} - A function that always passes null to it's callback as + * the error. The second argument to the callback will be an `object` with + * either an `error` or a `value` property. + * @example + * + * async.parallel([ + * async.reflect(function(callback) { + * // do some stuff ... + * callback(null, 'one'); + * }), + * async.reflect(function(callback) { + * // do some more stuff but error ... + * callback('bad stuff happened'); + * }), + * async.reflect(function(callback) { + * // do some more stuff ... + * callback(null, 'two'); + * }) + * ], + * // optional callback + * function(err, results) { + * // values + * // results[0].value = 'one' + * // results[1].error = 'bad stuff happened' + * // results[2].value = 'two' + * }); + */ + function reflect(fn) { + var _fn = wrapAsync(fn); + return initialParams(function reflectOn(args, reflectCallback) { + args.push((error, ...cbArgs) => { + let retVal = {}; + if (error) { + retVal.error = error; + } + if (cbArgs.length > 0){ + var value = cbArgs; + if (cbArgs.length <= 1) { + [value] = cbArgs; + } + retVal.value = value; + } + reflectCallback(null, retVal); + }); + + return _fn.apply(this, args); + }); + } + + /** + * A helper function that wraps an array or an object of functions with `reflect`. + * + * @name reflectAll + * @static + * @memberOf module:Utils + * @method + * @see [async.reflect]{@link module:Utils.reflect} + * @category Util + * @param {Array|Object|Iterable} tasks - The collection of + * [async functions]{@link AsyncFunction} to wrap in `async.reflect`. + * @returns {Array} Returns an array of async functions, each wrapped in + * `async.reflect` + * @example + * + * let tasks = [ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * // do some more stuff but error ... + * callback(new Error('bad stuff happened')); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ]; + * + * async.parallel(async.reflectAll(tasks), + * // optional callback + * function(err, results) { + * // values + * // results[0].value = 'one' + * // results[1].error = Error('bad stuff happened') + * // results[2].value = 'two' + * }); + * + * // an example using an object instead of an array + * let tasks = { + * one: function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * two: function(callback) { + * callback('two'); + * }, + * three: function(callback) { + * setTimeout(function() { + * callback(null, 'three'); + * }, 100); + * } + * }; + * + * async.parallel(async.reflectAll(tasks), + * // optional callback + * function(err, results) { + * // values + * // results.one.value = 'one' + * // results.two.error = 'two' + * // results.three.value = 'three' + * }); + */ + function reflectAll(tasks) { + var results; + if (Array.isArray(tasks)) { + results = tasks.map(reflect); + } else { + results = {}; + Object.keys(tasks).forEach(key => { + results[key] = reflect.call(this, tasks[key]); + }); + } + return results; + } + + function reject(eachfn, arr, _iteratee, callback) { + const iteratee = wrapAsync(_iteratee); + return _filter(eachfn, arr, (value, cb) => { + iteratee(value, (err, v) => { + cb(err, !v); + }); + }, callback); + } + + /** + * The opposite of [`filter`]{@link module:Collections.filter}. Removes values that pass an `async` truth test. + * + * @name reject + * @static + * @memberOf module:Collections + * @method + * @see [async.filter]{@link module:Collections.filter} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {Function} iteratee - An async truth test to apply to each item in + * `coll`. + * The should complete with a boolean value as its `result`. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * + * const fileList = ['dir1/file1.txt','dir2/file3.txt','dir3/file6.txt']; + * + * // asynchronous function that checks if a file exists + * function fileExists(file, callback) { + * fs.access(file, fs.constants.F_OK, (err) => { + * callback(null, !err); + * }); + * } + * + * // Using callbacks + * async.reject(fileList, fileExists, function(err, results) { + * // [ 'dir3/file6.txt' ] + * // results now equals an array of the non-existing files + * }); + * + * // Using Promises + * async.reject(fileList, fileExists) + * .then( results => { + * console.log(results); + * // [ 'dir3/file6.txt' ] + * // results now equals an array of the non-existing files + * }).catch( err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let results = await async.reject(fileList, fileExists); + * console.log(results); + * // [ 'dir3/file6.txt' ] + * // results now equals an array of the non-existing files + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function reject$1 (coll, iteratee, callback) { + return reject(eachOf$1, coll, iteratee, callback) + } + var reject$2 = awaitify(reject$1, 3); + + /** + * The same as [`reject`]{@link module:Collections.reject} but runs a maximum of `limit` async operations at a + * time. + * + * @name rejectLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.reject]{@link module:Collections.reject} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {Function} iteratee - An async truth test to apply to each item in + * `coll`. + * The should complete with a boolean value as its `result`. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + */ + function rejectLimit (coll, limit, iteratee, callback) { + return reject(eachOfLimit(limit), coll, iteratee, callback) + } + var rejectLimit$1 = awaitify(rejectLimit, 4); + + /** + * The same as [`reject`]{@link module:Collections.reject} but runs only a single async operation at a time. + * + * @name rejectSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.reject]{@link module:Collections.reject} + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {Function} iteratee - An async truth test to apply to each item in + * `coll`. + * The should complete with a boolean value as its `result`. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Invoked with (err, results). + * @returns {Promise} a promise, if no callback is passed + */ + function rejectSeries (coll, iteratee, callback) { + return reject(eachOfSeries$1, coll, iteratee, callback) + } + var rejectSeries$1 = awaitify(rejectSeries, 3); + + function constant$1(value) { + return function () { + return value; + } + } + + /** + * Attempts to get a successful response from `task` no more than `times` times + * before returning an error. If the task is successful, the `callback` will be + * passed the result of the successful task. If all attempts fail, the callback + * will be passed the error and result (if any) of the final attempt. + * + * @name retry + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @see [async.retryable]{@link module:ControlFlow.retryable} + * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an + * object with `times` and `interval` or a number. + * * `times` - The number of attempts to make before giving up. The default + * is `5`. + * * `interval` - The time to wait between retries, in milliseconds. The + * default is `0`. The interval may also be specified as a function of the + * retry count (see example). + * * `errorFilter` - An optional synchronous function that is invoked on + * erroneous result. If it returns `true` the retry attempts will continue; + * if the function returns `false` the retry flow is aborted with the current + * attempt's error and result being returned to the final callback. + * Invoked with (err). + * * If `opts` is a number, the number specifies the number of times to retry, + * with the default interval of `0`. + * @param {AsyncFunction} task - An async function to retry. + * Invoked with (callback). + * @param {Function} [callback] - An optional callback which is called when the + * task has succeeded, or after the final failed attempt. It receives the `err` + * and `result` arguments of the last attempt at completing the `task`. Invoked + * with (err, results). + * @returns {Promise} a promise if no callback provided + * + * @example + * + * // The `retry` function can be used as a stand-alone control flow by passing + * // a callback, as shown below: + * + * // try calling apiMethod 3 times + * async.retry(3, apiMethod, function(err, result) { + * // do something with the result + * }); + * + * // try calling apiMethod 3 times, waiting 200 ms between each retry + * async.retry({times: 3, interval: 200}, apiMethod, function(err, result) { + * // do something with the result + * }); + * + * // try calling apiMethod 10 times with exponential backoff + * // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds) + * async.retry({ + * times: 10, + * interval: function(retryCount) { + * return 50 * Math.pow(2, retryCount); + * } + * }, apiMethod, function(err, result) { + * // do something with the result + * }); + * + * // try calling apiMethod the default 5 times no delay between each retry + * async.retry(apiMethod, function(err, result) { + * // do something with the result + * }); + * + * // try calling apiMethod only when error condition satisfies, all other + * // errors will abort the retry control flow and return to final callback + * async.retry({ + * errorFilter: function(err) { + * return err.message === 'Temporary error'; // only retry on a specific error + * } + * }, apiMethod, function(err, result) { + * // do something with the result + * }); + * + * // to retry individual methods that are not as reliable within other + * // control flow functions, use the `retryable` wrapper: + * async.auto({ + * users: api.getUsers.bind(api), + * payments: async.retryable(3, api.getPayments.bind(api)) + * }, function(err, results) { + * // do something with the results + * }); + * + */ + const DEFAULT_TIMES = 5; + const DEFAULT_INTERVAL = 0; + + function retry(opts, task, callback) { + var options = { + times: DEFAULT_TIMES, + intervalFunc: constant$1(DEFAULT_INTERVAL) + }; + + if (arguments.length < 3 && typeof opts === 'function') { + callback = task || promiseCallback(); + task = opts; + } else { + parseTimes(options, opts); + callback = callback || promiseCallback(); + } + + if (typeof task !== 'function') { + throw new Error("Invalid arguments for async.retry"); + } + + var _task = wrapAsync(task); + + var attempt = 1; + function retryAttempt() { + _task((err, ...args) => { + if (err === false) return + if (err && attempt++ < options.times && + (typeof options.errorFilter != 'function' || + options.errorFilter(err))) { + setTimeout(retryAttempt, options.intervalFunc(attempt - 1)); + } else { + callback(err, ...args); + } + }); + } + + retryAttempt(); + return callback[PROMISE_SYMBOL] + } + + function parseTimes(acc, t) { + if (typeof t === 'object') { + acc.times = +t.times || DEFAULT_TIMES; + + acc.intervalFunc = typeof t.interval === 'function' ? + t.interval : + constant$1(+t.interval || DEFAULT_INTERVAL); + + acc.errorFilter = t.errorFilter; + } else if (typeof t === 'number' || typeof t === 'string') { + acc.times = +t || DEFAULT_TIMES; + } else { + throw new Error("Invalid arguments for async.retry"); + } + } + + /** + * A close relative of [`retry`]{@link module:ControlFlow.retry}. This method + * wraps a task and makes it retryable, rather than immediately calling it + * with retries. + * + * @name retryable + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.retry]{@link module:ControlFlow.retry} + * @category Control Flow + * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - optional + * options, exactly the same as from `retry`, except for a `opts.arity` that + * is the arity of the `task` function, defaulting to `task.length` + * @param {AsyncFunction} task - the asynchronous function to wrap. + * This function will be passed any arguments passed to the returned wrapper. + * Invoked with (...args, callback). + * @returns {AsyncFunction} The wrapped function, which when invoked, will + * retry on an error, based on the parameters specified in `opts`. + * This function will accept the same parameters as `task`. + * @example + * + * async.auto({ + * dep1: async.retryable(3, getFromFlakyService), + * process: ["dep1", async.retryable(3, function (results, cb) { + * maybeProcessData(results.dep1, cb); + * })] + * }, callback); + */ + function retryable (opts, task) { + if (!task) { + task = opts; + opts = null; + } + let arity = (opts && opts.arity) || task.length; + if (isAsync(task)) { + arity += 1; + } + var _task = wrapAsync(task); + return initialParams((args, callback) => { + if (args.length < arity - 1 || callback == null) { + args.push(callback); + callback = promiseCallback(); + } + function taskFn(cb) { + _task(...args, cb); + } + + if (opts) retry(opts, taskFn, callback); + else retry(taskFn, callback); + + return callback[PROMISE_SYMBOL] + }); + } + + /** + * Run the functions in the `tasks` collection in series, each one running once + * the previous function has completed. If any functions in the series pass an + * error to its callback, no more functions are run, and `callback` is + * immediately called with the value of the error. Otherwise, `callback` + * receives an array of results when `tasks` have completed. + * + * It is also possible to use an object instead of an array. Each property will + * be run as a function, and the results will be passed to the final `callback` + * as an object instead of an array. This can be a more readable way of handling + * results from {@link async.series}. + * + * **Note** that while many implementations preserve the order of object + * properties, the [ECMAScript Language Specification](http://www.ecma-international.org/ecma-262/5.1/#sec-8.6) + * explicitly states that + * + * > The mechanics and order of enumerating the properties is not specified. + * + * So if you rely on the order in which your series of functions are executed, + * and want this to work on all platforms, consider using an array. + * + * @name series + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection containing + * [async functions]{@link AsyncFunction} to run in series. + * Each function can complete with any number of optional `result` values. + * @param {Function} [callback] - An optional callback to run once all the + * functions have completed. This function gets a results array (or object) + * containing all the result arguments passed to the `task` callbacks. Invoked + * with (err, result). + * @return {Promise} a promise, if no callback is passed + * @example + * + * //Using Callbacks + * async.series([ + * function(callback) { + * setTimeout(function() { + * // do some async task + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * // then do another async task + * callback(null, 'two'); + * }, 100); + * } + * ], function(err, results) { + * console.log(results); + * // results is equal to ['one','two'] + * }); + * + * // an example using objects instead of arrays + * async.series({ + * one: function(callback) { + * setTimeout(function() { + * // do some async task + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * // then do another async task + * callback(null, 2); + * }, 100); + * } + * }, function(err, results) { + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * }); + * + * //Using Promises + * async.series([ + * function(callback) { + * setTimeout(function() { + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * callback(null, 'two'); + * }, 100); + * } + * ]).then(results => { + * console.log(results); + * // results is equal to ['one','two'] + * }).catch(err => { + * console.log(err); + * }); + * + * // an example using an object instead of an array + * async.series({ + * one: function(callback) { + * setTimeout(function() { + * // do some async task + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * // then do another async task + * callback(null, 2); + * }, 100); + * } + * }).then(results => { + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * }).catch(err => { + * console.log(err); + * }); + * + * //Using async/await + * async () => { + * try { + * let results = await async.series([ + * function(callback) { + * setTimeout(function() { + * // do some async task + * callback(null, 'one'); + * }, 200); + * }, + * function(callback) { + * setTimeout(function() { + * // then do another async task + * callback(null, 'two'); + * }, 100); + * } + * ]); + * console.log(results); + * // results is equal to ['one','two'] + * } + * catch (err) { + * console.log(err); + * } + * } + * + * // an example using an object instead of an array + * async () => { + * try { + * let results = await async.parallel({ + * one: function(callback) { + * setTimeout(function() { + * // do some async task + * callback(null, 1); + * }, 200); + * }, + * two: function(callback) { + * setTimeout(function() { + * // then do another async task + * callback(null, 2); + * }, 100); + * } + * }); + * console.log(results); + * // results is equal to: { one: 1, two: 2 } + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function series(tasks, callback) { + return parallel(eachOfSeries$1, tasks, callback); + } + + /** + * Returns `true` if at least one element in the `coll` satisfies an async test. + * If any iteratee call returns `true`, the main `callback` is immediately + * called. + * + * @name some + * @static + * @memberOf module:Collections + * @method + * @alias any + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collections in parallel. + * The iteratee should complete with a boolean `result` value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the iteratee functions have finished. + * Result will be either `true` or `false` depending on the values of the async + * tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + * @example + * + * // dir1 is a directory that contains file1.txt, file2.txt + * // dir2 is a directory that contains file3.txt, file4.txt + * // dir3 is a directory that contains file5.txt + * // dir4 does not exist + * + * // asynchronous function that checks if a file exists + * function fileExists(file, callback) { + * fs.access(file, fs.constants.F_OK, (err) => { + * callback(null, !err); + * }); + * } + * + * // Using callbacks + * async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists, + * function(err, result) { + * console.log(result); + * // true + * // result is true since some file in the list exists + * } + *); + * + * async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists, + * function(err, result) { + * console.log(result); + * // false + * // result is false since none of the files exists + * } + *); + * + * // Using Promises + * async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists) + * .then( result => { + * console.log(result); + * // true + * // result is true since some file in the list exists + * }).catch( err => { + * console.log(err); + * }); + * + * async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists) + * .then( result => { + * console.log(result); + * // false + * // result is false since none of the files exists + * }).catch( err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists); + * console.log(result); + * // true + * // result is true since some file in the list exists + * } + * catch (err) { + * console.log(err); + * } + * } + * + * async () => { + * try { + * let result = await async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists); + * console.log(result); + * // false + * // result is false since none of the files exists + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function some(coll, iteratee, callback) { + return _createTester(Boolean, res => res)(eachOf$1, coll, iteratee, callback) + } + var some$1 = awaitify(some, 3); + + /** + * The same as [`some`]{@link module:Collections.some} but runs a maximum of `limit` async operations at a time. + * + * @name someLimit + * @static + * @memberOf module:Collections + * @method + * @see [async.some]{@link module:Collections.some} + * @alias anyLimit + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collections in parallel. + * The iteratee should complete with a boolean `result` value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the iteratee functions have finished. + * Result will be either `true` or `false` depending on the values of the async + * tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + */ + function someLimit(coll, limit, iteratee, callback) { + return _createTester(Boolean, res => res)(eachOfLimit(limit), coll, iteratee, callback) + } + var someLimit$1 = awaitify(someLimit, 4); + + /** + * The same as [`some`]{@link module:Collections.some} but runs only a single async operation at a time. + * + * @name someSeries + * @static + * @memberOf module:Collections + * @method + * @see [async.some]{@link module:Collections.some} + * @alias anySeries + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async truth test to apply to each item + * in the collections in series. + * The iteratee should complete with a boolean `result` value. + * Invoked with (item, callback). + * @param {Function} [callback] - A callback which is called as soon as any + * iteratee returns `true`, or after all the iteratee functions have finished. + * Result will be either `true` or `false` depending on the values of the async + * tests. Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + */ + function someSeries(coll, iteratee, callback) { + return _createTester(Boolean, res => res)(eachOfSeries$1, coll, iteratee, callback) + } + var someSeries$1 = awaitify(someSeries, 3); + + /** + * Sorts a list by the results of running each `coll` value through an async + * `iteratee`. + * + * @name sortBy + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {AsyncFunction} iteratee - An async function to apply to each item in + * `coll`. + * The iteratee should complete with a value to use as the sort criteria as + * its `result`. + * Invoked with (item, callback). + * @param {Function} callback - A callback which is called after all the + * `iteratee` functions have finished, or an error occurs. Results is the items + * from the original `coll` sorted by the values returned by the `iteratee` + * calls. Invoked with (err, results). + * @returns {Promise} a promise, if no callback passed + * @example + * + * // bigfile.txt is a file that is 251100 bytes in size + * // mediumfile.txt is a file that is 11000 bytes in size + * // smallfile.txt is a file that is 121 bytes in size + * + * // asynchronous function that returns the file size in bytes + * function getFileSizeInBytes(file, callback) { + * fs.stat(file, function(err, stat) { + * if (err) { + * return callback(err); + * } + * callback(null, stat.size); + * }); + * } + * + * // Using callbacks + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes, + * function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * } + * ); + * + * // By modifying the callback parameter the + * // sorting order can be influenced: + * + * // ascending order + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], function(file, callback) { + * getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { + * if (getFileSizeErr) return callback(getFileSizeErr); + * callback(null, fileSize); + * }); + * }, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * } + * ); + * + * // descending order + * async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], function(file, callback) { + * getFileSizeInBytes(file, function(getFileSizeErr, fileSize) { + * if (getFileSizeErr) { + * return callback(getFileSizeErr); + * } + * callback(null, fileSize * -1); + * }); + * }, function(err, results) { + * if (err) { + * console.log(err); + * } else { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'bigfile.txt', 'mediumfile.txt', 'smallfile.txt'] + * } + * } + * ); + * + * // Error handling + * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes, + * function(err, results) { + * if (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } else { + * console.log(results); + * } + * } + * ); + * + * // Using Promises + * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes) + * .then( results => { + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * }).catch( err => { + * console.log(err); + * }); + * + * // Error handling + * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes) + * .then( results => { + * console.log(results); + * }).catch( err => { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * }); + * + * // Using async/await + * (async () => { + * try { + * let results = await async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); + * console.log(results); + * // results is now the original array of files sorted by + * // file size (ascending by default), e.g. + * // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt'] + * } + * catch (err) { + * console.log(err); + * } + * })(); + * + * // Error handling + * async () => { + * try { + * let results = await async.sortBy(['missingfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes); + * console.log(results); + * } + * catch (err) { + * console.log(err); + * // [ Error: ENOENT: no such file or directory ] + * } + * } + * + */ + function sortBy (coll, iteratee, callback) { + var _iteratee = wrapAsync(iteratee); + return map$1(coll, (x, iterCb) => { + _iteratee(x, (err, criteria) => { + if (err) return iterCb(err); + iterCb(err, {value: x, criteria}); + }); + }, (err, results) => { + if (err) return callback(err); + callback(null, results.sort(comparator).map(v => v.value)); + }); + + function comparator(left, right) { + var a = left.criteria, b = right.criteria; + return a < b ? -1 : a > b ? 1 : 0; + } + } + var sortBy$1 = awaitify(sortBy, 3); + + /** + * Sets a time limit on an asynchronous function. If the function does not call + * its callback within the specified milliseconds, it will be called with a + * timeout error. The code property for the error object will be `'ETIMEDOUT'`. + * + * @name timeout + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} asyncFn - The async function to limit in time. + * @param {number} milliseconds - The specified time limit. + * @param {*} [info] - Any variable you want attached (`string`, `object`, etc) + * to timeout Error for more information.. + * @returns {AsyncFunction} Returns a wrapped function that can be used with any + * of the control flow functions. + * Invoke this function with the same parameters as you would `asyncFunc`. + * @example + * + * function myFunction(foo, callback) { + * doAsyncTask(foo, function(err, data) { + * // handle errors + * if (err) return callback(err); + * + * // do some stuff ... + * + * // return processed data + * return callback(null, data); + * }); + * } + * + * var wrapped = async.timeout(myFunction, 1000); + * + * // call `wrapped` as you would `myFunction` + * wrapped({ bar: 'bar' }, function(err, data) { + * // if `myFunction` takes < 1000 ms to execute, `err` + * // and `data` will have their expected values + * + * // else `err` will be an Error with the code 'ETIMEDOUT' + * }); + */ + function timeout(asyncFn, milliseconds, info) { + var fn = wrapAsync(asyncFn); + + return initialParams((args, callback) => { + var timedOut = false; + var timer; + + function timeoutCallback() { + var name = asyncFn.name || 'anonymous'; + var error = new Error('Callback function "' + name + '" timed out.'); + error.code = 'ETIMEDOUT'; + if (info) { + error.info = info; + } + timedOut = true; + callback(error); + } + + args.push((...cbArgs) => { + if (!timedOut) { + callback(...cbArgs); + clearTimeout(timer); + } + }); + + // setup timer and call original function + timer = setTimeout(timeoutCallback, milliseconds); + fn(...args); + }); + } + + function range(size) { + var result = Array(size); + while (size--) { + result[size] = size; + } + return result; + } + + /** + * The same as [times]{@link module:ControlFlow.times} but runs a maximum of `limit` async operations at a + * time. + * + * @name timesLimit + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.times]{@link module:ControlFlow.times} + * @category Control Flow + * @param {number} count - The number of times to run the function. + * @param {number} limit - The maximum number of async operations at a time. + * @param {AsyncFunction} iteratee - The async function to call `n` times. + * Invoked with the iteration index and a callback: (n, next). + * @param {Function} callback - see [async.map]{@link module:Collections.map}. + * @returns {Promise} a promise, if no callback is provided + */ + function timesLimit(count, limit, iteratee, callback) { + var _iteratee = wrapAsync(iteratee); + return mapLimit$1(range(count), limit, _iteratee, callback); + } + + /** + * Calls the `iteratee` function `n` times, and accumulates results in the same + * manner you would use with [map]{@link module:Collections.map}. + * + * @name times + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.map]{@link module:Collections.map} + * @category Control Flow + * @param {number} n - The number of times to run the function. + * @param {AsyncFunction} iteratee - The async function to call `n` times. + * Invoked with the iteration index and a callback: (n, next). + * @param {Function} callback - see {@link module:Collections.map}. + * @returns {Promise} a promise, if no callback is provided + * @example + * + * // Pretend this is some complicated async factory + * var createUser = function(id, callback) { + * callback(null, { + * id: 'user' + id + * }); + * }; + * + * // generate 5 users + * async.times(5, function(n, next) { + * createUser(n, function(err, user) { + * next(err, user); + * }); + * }, function(err, users) { + * // we should now have 5 users + * }); + */ + function times (n, iteratee, callback) { + return timesLimit(n, Infinity, iteratee, callback) + } + + /** + * The same as [times]{@link module:ControlFlow.times} but runs only a single async operation at a time. + * + * @name timesSeries + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.times]{@link module:ControlFlow.times} + * @category Control Flow + * @param {number} n - The number of times to run the function. + * @param {AsyncFunction} iteratee - The async function to call `n` times. + * Invoked with the iteration index and a callback: (n, next). + * @param {Function} callback - see {@link module:Collections.map}. + * @returns {Promise} a promise, if no callback is provided + */ + function timesSeries (n, iteratee, callback) { + return timesLimit(n, 1, iteratee, callback) + } + + /** + * A relative of `reduce`. Takes an Object or Array, and iterates over each + * element in parallel, each step potentially mutating an `accumulator` value. + * The type of the accumulator defaults to the type of collection passed in. + * + * @name transform + * @static + * @memberOf module:Collections + * @method + * @category Collection + * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over. + * @param {*} [accumulator] - The initial state of the transform. If omitted, + * it will default to an empty Object or Array, depending on the type of `coll` + * @param {AsyncFunction} iteratee - A function applied to each item in the + * collection that potentially modifies the accumulator. + * Invoked with (accumulator, item, key, callback). + * @param {Function} [callback] - A callback which is called after all the + * `iteratee` functions have finished. Result is the transformed accumulator. + * Invoked with (err, result). + * @returns {Promise} a promise, if no callback provided + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * + * // helper function that returns human-readable size format from bytes + * function formatBytes(bytes, decimals = 2) { + * // implementation not included for brevity + * return humanReadbleFilesize; + * } + * + * const fileList = ['file1.txt','file2.txt','file3.txt']; + * + * // asynchronous function that returns the file size, transformed to human-readable format + * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc. + * function transformFileSize(acc, value, key, callback) { + * fs.stat(value, function(err, stat) { + * if (err) { + * return callback(err); + * } + * acc[key] = formatBytes(stat.size); + * callback(null); + * }); + * } + * + * // Using callbacks + * async.transform(fileList, transformFileSize, function(err, result) { + * if(err) { + * console.log(err); + * } else { + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * } + * }); + * + * // Using Promises + * async.transform(fileList, transformFileSize) + * .then(result => { + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * (async () => { + * try { + * let result = await async.transform(fileList, transformFileSize); + * console.log(result); + * // [ '1000 Bytes', '1.95 KB', '2.93 KB' ] + * } + * catch (err) { + * console.log(err); + * } + * })(); + * + * @example + * + * // file1.txt is a file that is 1000 bytes in size + * // file2.txt is a file that is 2000 bytes in size + * // file3.txt is a file that is 3000 bytes in size + * + * // helper function that returns human-readable size format from bytes + * function formatBytes(bytes, decimals = 2) { + * // implementation not included for brevity + * return humanReadbleFilesize; + * } + * + * const fileMap = { f1: 'file1.txt', f2: 'file2.txt', f3: 'file3.txt' }; + * + * // asynchronous function that returns the file size, transformed to human-readable format + * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc. + * function transformFileSize(acc, value, key, callback) { + * fs.stat(value, function(err, stat) { + * if (err) { + * return callback(err); + * } + * acc[key] = formatBytes(stat.size); + * callback(null); + * }); + * } + * + * // Using callbacks + * async.transform(fileMap, transformFileSize, function(err, result) { + * if(err) { + * console.log(err); + * } else { + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * } + * }); + * + * // Using Promises + * async.transform(fileMap, transformFileSize) + * .then(result => { + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * }).catch(err => { + * console.log(err); + * }); + * + * // Using async/await + * async () => { + * try { + * let result = await async.transform(fileMap, transformFileSize); + * console.log(result); + * // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' } + * } + * catch (err) { + * console.log(err); + * } + * } + * + */ + function transform (coll, accumulator, iteratee, callback) { + if (arguments.length <= 3 && typeof accumulator === 'function') { + callback = iteratee; + iteratee = accumulator; + accumulator = Array.isArray(coll) ? [] : {}; + } + callback = once(callback || promiseCallback()); + var _iteratee = wrapAsync(iteratee); + + eachOf$1(coll, (v, k, cb) => { + _iteratee(accumulator, v, k, cb); + }, err => callback(err, accumulator)); + return callback[PROMISE_SYMBOL] + } + + /** + * It runs each task in series but stops whenever any of the functions were + * successful. If one of the tasks were successful, the `callback` will be + * passed the result of the successful task. If all tasks fail, the callback + * will be passed the error and result (if any) of the final attempt. + * + * @name tryEach + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection containing functions to + * run, each function is passed a `callback(err, result)` it must call on + * completion with an error `err` (which can be `null`) and an optional `result` + * value. + * @param {Function} [callback] - An optional callback which is called when one + * of the tasks has succeeded, or all have failed. It receives the `err` and + * `result` arguments of the last attempt at completing the `task`. Invoked with + * (err, results). + * @returns {Promise} a promise, if no callback is passed + * @example + * async.tryEach([ + * function getDataFromFirstWebsite(callback) { + * // Try getting the data from the first website + * callback(err, data); + * }, + * function getDataFromSecondWebsite(callback) { + * // First website failed, + * // Try getting the data from the backup website + * callback(err, data); + * } + * ], + * // optional callback + * function(err, results) { + * Now do something with the data. + * }); + * + */ + function tryEach(tasks, callback) { + var error = null; + var result; + return eachSeries$1(tasks, (task, taskCb) => { + wrapAsync(task)((err, ...args) => { + if (err === false) return taskCb(err); + + if (args.length < 2) { + [result] = args; + } else { + result = args; + } + error = err; + taskCb(err ? null : {}); + }); + }, () => callback(error, result)); + } + + var tryEach$1 = awaitify(tryEach); + + /** + * Undoes a [memoize]{@link module:Utils.memoize}d function, reverting it to the original, + * unmemoized form. Handy for testing. + * + * @name unmemoize + * @static + * @memberOf module:Utils + * @method + * @see [async.memoize]{@link module:Utils.memoize} + * @category Util + * @param {AsyncFunction} fn - the memoized function + * @returns {AsyncFunction} a function that calls the original unmemoized function + */ + function unmemoize(fn) { + return (...args) => { + return (fn.unmemoized || fn)(...args); + }; + } + + /** + * Repeatedly call `iteratee`, while `test` returns `true`. Calls `callback` when + * stopped, or an error occurs. + * + * @name whilst + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {AsyncFunction} test - asynchronous truth test to perform before each + * execution of `iteratee`. Invoked with (). + * @param {AsyncFunction} iteratee - An async function which is called each time + * `test` passes. Invoked with (callback). + * @param {Function} [callback] - A callback which is called after the test + * function has failed and repeated execution of `iteratee` has stopped. `callback` + * will be passed an error and any arguments passed to the final `iteratee`'s + * callback. Invoked with (err, [results]); + * @returns {Promise} a promise, if no callback is passed + * @example + * + * var count = 0; + * async.whilst( + * function test(cb) { cb(null, count < 5); }, + * function iter(callback) { + * count++; + * setTimeout(function() { + * callback(null, count); + * }, 1000); + * }, + * function (err, n) { + * // 5 seconds have passed, n = 5 + * } + * ); + */ + function whilst(test, iteratee, callback) { + callback = onlyOnce(callback); + var _fn = wrapAsync(iteratee); + var _test = wrapAsync(test); + var results = []; + + function next(err, ...rest) { + if (err) return callback(err); + results = rest; + if (err === false) return; + _test(check); + } + + function check(err, truth) { + if (err) return callback(err); + if (err === false) return; + if (!truth) return callback(null, ...results); + _fn(next); + } + + return _test(check); + } + var whilst$1 = awaitify(whilst, 3); + + /** + * Repeatedly call `iteratee` until `test` returns `true`. Calls `callback` when + * stopped, or an error occurs. `callback` will be passed an error and any + * arguments passed to the final `iteratee`'s callback. + * + * The inverse of [whilst]{@link module:ControlFlow.whilst}. + * + * @name until + * @static + * @memberOf module:ControlFlow + * @method + * @see [async.whilst]{@link module:ControlFlow.whilst} + * @category Control Flow + * @param {AsyncFunction} test - asynchronous truth test to perform before each + * execution of `iteratee`. Invoked with (callback). + * @param {AsyncFunction} iteratee - An async function which is called each time + * `test` fails. Invoked with (callback). + * @param {Function} [callback] - A callback which is called after the test + * function has passed and repeated execution of `iteratee` has stopped. `callback` + * will be passed an error and any arguments passed to the final `iteratee`'s + * callback. Invoked with (err, [results]); + * @returns {Promise} a promise, if a callback is not passed + * + * @example + * const results = [] + * let finished = false + * async.until(function test(cb) { + * cb(null, finished) + * }, function iter(next) { + * fetchPage(url, (err, body) => { + * if (err) return next(err) + * results = results.concat(body.objects) + * finished = !!body.next + * next(err) + * }) + * }, function done (err) { + * // all pages have been fetched + * }) + */ + function until(test, iteratee, callback) { + const _test = wrapAsync(test); + return whilst$1((cb) => _test((err, truth) => cb (err, !truth)), iteratee, callback); + } + + /** + * Runs the `tasks` array of functions in series, each passing their results to + * the next in the array. However, if any of the `tasks` pass an error to their + * own callback, the next function is not executed, and the main `callback` is + * immediately called with the error. + * + * @name waterfall + * @static + * @memberOf module:ControlFlow + * @method + * @category Control Flow + * @param {Array} tasks - An array of [async functions]{@link AsyncFunction} + * to run. + * Each function should complete with any number of `result` values. + * The `result` values will be passed as arguments, in order, to the next task. + * @param {Function} [callback] - An optional callback to run once all the + * functions have completed. This will be passed the results of the last task's + * callback. Invoked with (err, [results]). + * @returns {Promise} a promise, if a callback is omitted + * @example + * + * async.waterfall([ + * function(callback) { + * callback(null, 'one', 'two'); + * }, + * function(arg1, arg2, callback) { + * // arg1 now equals 'one' and arg2 now equals 'two' + * callback(null, 'three'); + * }, + * function(arg1, callback) { + * // arg1 now equals 'three' + * callback(null, 'done'); + * } + * ], function (err, result) { + * // result now equals 'done' + * }); + * + * // Or, with named functions: + * async.waterfall([ + * myFirstFunction, + * mySecondFunction, + * myLastFunction, + * ], function (err, result) { + * // result now equals 'done' + * }); + * function myFirstFunction(callback) { + * callback(null, 'one', 'two'); + * } + * function mySecondFunction(arg1, arg2, callback) { + * // arg1 now equals 'one' and arg2 now equals 'two' + * callback(null, 'three'); + * } + * function myLastFunction(arg1, callback) { + * // arg1 now equals 'three' + * callback(null, 'done'); + * } + */ + function waterfall (tasks, callback) { + callback = once(callback); + if (!Array.isArray(tasks)) return callback(new Error('First argument to waterfall must be an array of functions')); + if (!tasks.length) return callback(); + var taskIndex = 0; + + function nextTask(args) { + var task = wrapAsync(tasks[taskIndex++]); + task(...args, onlyOnce(next)); + } + + function next(err, ...args) { + if (err === false) return + if (err || taskIndex === tasks.length) { + return callback(err, ...args); + } + nextTask(args); + } + + nextTask([]); + } + + var waterfall$1 = awaitify(waterfall); + + /** + * An "async function" in the context of Async is an asynchronous function with + * a variable number of parameters, with the final parameter being a callback. + * (`function (arg1, arg2, ..., callback) {}`) + * The final callback is of the form `callback(err, results...)`, which must be + * called once the function is completed. The callback should be called with a + * Error as its first argument to signal that an error occurred. + * Otherwise, if no error occurred, it should be called with `null` as the first + * argument, and any additional `result` arguments that may apply, to signal + * successful completion. + * The callback must be called exactly once, ideally on a later tick of the + * JavaScript event loop. + * + * This type of function is also referred to as a "Node-style async function", + * or a "continuation passing-style function" (CPS). Most of the methods of this + * library are themselves CPS/Node-style async functions, or functions that + * return CPS/Node-style async functions. + * + * Wherever we accept a Node-style async function, we also directly accept an + * [ES2017 `async` function]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function}. + * In this case, the `async` function will not be passed a final callback + * argument, and any thrown error will be used as the `err` argument of the + * implicit callback, and the return value will be used as the `result` value. + * (i.e. a `rejected` of the returned Promise becomes the `err` callback + * argument, and a `resolved` value becomes the `result`.) + * + * Note, due to JavaScript limitations, we can only detect native `async` + * functions and not transpilied implementations. + * Your environment must have `async`/`await` support for this to work. + * (e.g. Node > v7.6, or a recent version of a modern browser). + * If you are using `async` functions through a transpiler (e.g. Babel), you + * must still wrap the function with [asyncify]{@link module:Utils.asyncify}, + * because the `async function` will be compiled to an ordinary function that + * returns a promise. + * + * @typedef {Function} AsyncFunction + * @static + */ + + var index = { + apply, + applyEach: applyEach$1, + applyEachSeries, + asyncify, + auto, + autoInject, + cargo, + cargoQueue: cargo$1, + compose, + concat: concat$1, + concatLimit: concatLimit$1, + concatSeries: concatSeries$1, + constant, + detect: detect$1, + detectLimit: detectLimit$1, + detectSeries: detectSeries$1, + dir, + doUntil, + doWhilst: doWhilst$1, + each, + eachLimit: eachLimit$2, + eachOf: eachOf$1, + eachOfLimit: eachOfLimit$2, + eachOfSeries: eachOfSeries$1, + eachSeries: eachSeries$1, + ensureAsync, + every: every$1, + everyLimit: everyLimit$1, + everySeries: everySeries$1, + filter: filter$1, + filterLimit: filterLimit$1, + filterSeries: filterSeries$1, + forever: forever$1, + groupBy, + groupByLimit: groupByLimit$1, + groupBySeries, + log, + map: map$1, + mapLimit: mapLimit$1, + mapSeries: mapSeries$1, + mapValues, + mapValuesLimit: mapValuesLimit$1, + mapValuesSeries, + memoize, + nextTick, + parallel: parallel$1, + parallelLimit, + priorityQueue, + queue: queue$1, + race: race$1, + reduce: reduce$1, + reduceRight, + reflect, + reflectAll, + reject: reject$2, + rejectLimit: rejectLimit$1, + rejectSeries: rejectSeries$1, + retry, + retryable, + seq, + series, + setImmediate: setImmediate$1, + some: some$1, + someLimit: someLimit$1, + someSeries: someSeries$1, + sortBy: sortBy$1, + timeout, + times, + timesLimit, + timesSeries, + transform, + tryEach: tryEach$1, + unmemoize, + until, + waterfall: waterfall$1, + whilst: whilst$1, + + // aliases + all: every$1, + allLimit: everyLimit$1, + allSeries: everySeries$1, + any: some$1, + anyLimit: someLimit$1, + anySeries: someSeries$1, + find: detect$1, + findLimit: detectLimit$1, + findSeries: detectSeries$1, + flatMap: concat$1, + flatMapLimit: concatLimit$1, + flatMapSeries: concatSeries$1, + forEach: each, + forEachSeries: eachSeries$1, + forEachLimit: eachLimit$2, + forEachOf: eachOf$1, + forEachOfSeries: eachOfSeries$1, + forEachOfLimit: eachOfLimit$2, + inject: reduce$1, + foldl: reduce$1, + foldr: reduceRight, + select: filter$1, + selectLimit: filterLimit$1, + selectSeries: filterSeries$1, + wrapSync: asyncify, + during: whilst$1, + doDuring: doWhilst$1 + }; + + exports.default = index; + exports.apply = apply; + exports.applyEach = applyEach$1; + exports.applyEachSeries = applyEachSeries; + exports.asyncify = asyncify; + exports.auto = auto; + exports.autoInject = autoInject; + exports.cargo = cargo; + exports.cargoQueue = cargo$1; + exports.compose = compose; + exports.concat = concat$1; + exports.concatLimit = concatLimit$1; + exports.concatSeries = concatSeries$1; + exports.constant = constant; + exports.detect = detect$1; + exports.detectLimit = detectLimit$1; + exports.detectSeries = detectSeries$1; + exports.dir = dir; + exports.doUntil = doUntil; + exports.doWhilst = doWhilst$1; + exports.each = each; + exports.eachLimit = eachLimit$2; + exports.eachOf = eachOf$1; + exports.eachOfLimit = eachOfLimit$2; + exports.eachOfSeries = eachOfSeries$1; + exports.eachSeries = eachSeries$1; + exports.ensureAsync = ensureAsync; + exports.every = every$1; + exports.everyLimit = everyLimit$1; + exports.everySeries = everySeries$1; + exports.filter = filter$1; + exports.filterLimit = filterLimit$1; + exports.filterSeries = filterSeries$1; + exports.forever = forever$1; + exports.groupBy = groupBy; + exports.groupByLimit = groupByLimit$1; + exports.groupBySeries = groupBySeries; + exports.log = log; + exports.map = map$1; + exports.mapLimit = mapLimit$1; + exports.mapSeries = mapSeries$1; + exports.mapValues = mapValues; + exports.mapValuesLimit = mapValuesLimit$1; + exports.mapValuesSeries = mapValuesSeries; + exports.memoize = memoize; + exports.nextTick = nextTick; + exports.parallel = parallel$1; + exports.parallelLimit = parallelLimit; + exports.priorityQueue = priorityQueue; + exports.queue = queue$1; + exports.race = race$1; + exports.reduce = reduce$1; + exports.reduceRight = reduceRight; + exports.reflect = reflect; + exports.reflectAll = reflectAll; + exports.reject = reject$2; + exports.rejectLimit = rejectLimit$1; + exports.rejectSeries = rejectSeries$1; + exports.retry = retry; + exports.retryable = retryable; + exports.seq = seq; + exports.series = series; + exports.setImmediate = setImmediate$1; + exports.some = some$1; + exports.someLimit = someLimit$1; + exports.someSeries = someSeries$1; + exports.sortBy = sortBy$1; + exports.timeout = timeout; + exports.times = times; + exports.timesLimit = timesLimit; + exports.timesSeries = timesSeries; + exports.transform = transform; + exports.tryEach = tryEach$1; + exports.unmemoize = unmemoize; + exports.until = until; + exports.waterfall = waterfall$1; + exports.whilst = whilst$1; + exports.all = every$1; + exports.allLimit = everyLimit$1; + exports.allSeries = everySeries$1; + exports.any = some$1; + exports.anyLimit = someLimit$1; + exports.anySeries = someSeries$1; + exports.find = detect$1; + exports.findLimit = detectLimit$1; + exports.findSeries = detectSeries$1; + exports.flatMap = concat$1; + exports.flatMapLimit = concatLimit$1; + exports.flatMapSeries = concatSeries$1; + exports.forEach = each; + exports.forEachSeries = eachSeries$1; + exports.forEachLimit = eachLimit$2; + exports.forEachOf = eachOf$1; + exports.forEachOfSeries = eachOfSeries$1; + exports.forEachOfLimit = eachOfLimit$2; + exports.inject = reduce$1; + exports.foldl = reduce$1; + exports.foldr = reduceRight; + exports.select = filter$1; + exports.selectLimit = filterLimit$1; + exports.selectSeries = filterSeries$1; + exports.wrapSync = asyncify; + exports.during = whilst$1; + exports.doDuring = doWhilst$1; + + Object.defineProperty(exports, '__esModule', { value: true }); + +}))); -- cgit