package/package.json000644 000765 000024 0000003302 13140434522013011 0ustar00000000 000000 { "name": "bach", "version": "1.2.0", "description": "Compose your async functions with elegance.", "author": "Gulp Team (http://gulpjs.com/)", "contributors": [ "Blaine Bublitz ", "Pawel Kozlowski ", "Benjamin Tan " ], "repository": "gulpjs/bach", "license": "MIT", "engines": { "node": ">= 0.10" }, "main": "index.js", "files": [ "index.js", "lib", "LICENSE" ], "scripts": { "lint": "eslint . && jscs index.js lib/ test/", "pretest": "npm run lint", "test": "mocha --async-only", "cover": "istanbul cover _mocha --report lcovonly", "coveralls": "npm run cover && istanbul-coveralls" }, "dependencies": { "arr-filter": "^1.1.1", "arr-flatten": "^1.0.1", "arr-map": "^2.0.0", "array-each": "^1.0.0", "array-initial": "^1.0.0", "array-last": "^1.1.1", "async-done": "^1.2.2", "async-settle": "^1.0.0", "now-and-later": "^2.0.0" }, "devDependencies": { "eslint": "^1.7.3", "eslint-config-gulp": "^2.0.0", "expect": "^1.19.0", "istanbul": "^0.4.3", "istanbul-coveralls": "^1.0.3", "jscs": "^2.3.5", "jscs-preset-gulp": "^1.0.0", "mocha": "^2.4.5" }, "keywords": [ "compose", "fluent", "composing", "continuation", "function composition", "functional", "async", "map", "series", "parallel", "extension", "tracing", "debug", "timing", "aop", "settle", "promises", "callbacks", "observables", "streams", "end", "completion", "complete", "finish", "done", "error handling" ] } package/README.md000644 000765 000024 0000020645 13054460766012030 0ustar00000000 000000

# bach [![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][travis-image]][travis-url] [![AppVeyor Build Status][appveyor-image]][appveyor-url] [![Coveralls Status][coveralls-image]][coveralls-url] [![Gitter chat][gitter-image]][gitter-url] Compose your async functions with elegance. ## Usage With `bach`, it is very easy to compose async functions to run in series or parallel. ```js var bach = require('bach'); function fn1(cb) { cb(null, 1); } function fn2(cb) { cb(null, 2); } function fn3(cb) { cb(null, 3); } var seriesFn = bach.series(fn1, fn2, fn3); // fn1, fn2, and fn3 will be run in series seriesFn(function(err, res) { if (err) { // in this example, err is undefined // handle error } // handle results // in this example, res is [1, 2, 3] }); var parallelFn = bach.parallel(fn1, fn2, fn3); // fn1, fn2, and fn3 will be run in parallel parallelFn(function(err, res) { if (err) { // in this example, err is undefined // handle error } // handle results // in this example, res is [1, 2, 3] }); ``` Since the composer functions return a function, you can combine them. ```js var combinedFn = bach.series(fn1, bach.parallel(fn2, fn3)); // fn1 will be executed before fn2 and fn3 are run in parallel combinedFn(function(err, res) { if (err) { // in this example, err is undefined // handle error } // handle results // in this example, res is [1, [2, 3]] }); ``` Functions are called with [async-done], so you can return a stream, promise, observable or child process. See [`async-done` completion and error resolution][completions] for more detail. ```js // streams var fs = require('fs'); function streamFn1() { return fs.createReadStream('./example') .pipe(fs.createWriteStream('./example')); } function streamFn2() { return fs.createReadStream('./example') .pipe(fs.createWriteStream('./example')); } var parallelStreams = bach.parallel(streamFn1, streamFn2); parallelStreams(function(err) { if (err) { // in this example, err is undefined // handle error } // all streams have emitted an 'end' or 'close' event }); ``` ```js // promises var when = require('when'); function promiseFn1() { return when.resolve(1); } function promiseFn2() { return when.resolve(2); } var parallelPromises = bach.parallel(promiseFn1, promiseFn2); parallelPromises(function(err, res) { if (err) { // in this example, err is undefined // handle error } // handle results // in this example, res is [1, 2] }); ``` All errors are caught in a [domain] and passed to the final callback as the first argument. ```js function success(cb) { setTimeout(function() { cb(null, 1); }, 500); } function error() { throw new Error('Thrown Error'); } var errorThrownFn = bach.parallel(error, success); errorThrownFn(function(err, res) { if (err) { // handle error // in this example, err is an error caught by the domain } // handle results // in this example, res is [undefined] }); ``` When an error happens in a parallel composition, the callback will be called as soon as the error happens. If you want to continue on error and wait until all functions have finished before calling the callback, use `settleSeries` or `settleParallel`. ```js function success(cb) { setTimeout(function() { cb(null, 1); }, 500); } function error(cb) { cb(new Error('Async Error')); } var parallelSettlingFn = bach.settleParallel(success, error); parallelSettlingFn(function(err, res) { // all functions have finished executing if (err) { // handle error // in this example, err is an error passed to the callback } // handle results // in this example, res is [1] }); ``` ## API ### `series(fns..., [extensions])` Takes a variable amount of functions (`fns`) to be called in series when the returned function is called. Optionally, takes an [extensions](#extensions) object as the last argument. Returns an `invoker(cb)` function to be called to start the serial execution. The invoker function takes a callback (`cb`) with the `function(error, results)` signature. If all functions complete successfully, the callback function will be called with all `results` as the second argument. If an error occurs, execution will stop and the error will be passed to the callback function as the first parameter. The error parameter will always be a single error. ### `parallel(fns..., [extensions])` Takes a variable amount of functions (`fns`) to be called in parallel when the returned function is called. Optionally, takes an [extensions](#extensions) object as the last argument. Returns an `invoker(cb)` function to be called to start the parallel execution. The invoker function takes a callback (`cb`) with the `function(error, results)` signature. If all functions complete successfully, the callback function will be called with all `results` as the second argument. If an error occurs, the callback function will be called with the error as the first parameter. Any async functions that have not completed, will still complete, but their results will __not__ be available. The error parameter will always be a single error. ### `settleSeries(fns..., [extensions])` Takes a variable amount of functions (`fns`) to be called in series when the returned function is called. Optionally, takes an [extensions](#extensions) object as the last argument. Returns an `invoker(cb)` function to be called to start the serial execution. The invoker function takes a callback (`cb`) with the `function(error, results)` signature. All functions will always be called and the callback will receive all settled errors and results. If any errors occur, the error parameter will be an array of errors. ### `settleParallel(fns..., [extensions])` Takes a variable amount of functions (`fns`) to be called in parallel when the returned function is called. Optionally, takes an [extensions](#extensions) object as the last argument. Returns an `invoker(cb)` function to be called to start the parallel execution. The invoker function takes a callback (`cb`) with the `function(error, results)` signature. All functions will always be called and the callback will receive all settled errors and results. If any errors occur, the error parameter will be an array of errors. ### `extensions` The `extensions` object is used for specifying functions that give insight into the lifecycle of each function call. The possible extension points are `create`, `before`, `after` and `error`. If an extension point is not specified, it defaults to a no-op function. ##### `extensions.create(fn, index)` Called at the very beginning of each function call with the function (`fn`) being executed and the `index` from the array/arguments. If `create` returns a value (`storage`), it is passed to the `before`, `after` and `error` extension points. If a value is not returned, an empty object is used as `storage` for each other extension point. This is useful for tracking information across an iteration. ##### `extensions.before(storage)` Called immediately before each function call with the `storage` value returned from the `create` extension point. ##### `extensions.after(result, storage)` Called immediately after each function call with the `result` of the function and the `storage` value returned from the `create` extension point. ##### `extensions.error(error, storage)` Called immediately after a failed function call with the `error` of the function and the `storage` value returned from the `create` extension point. ## License MIT [domain]: http://nodejs.org/api/domain.html [async-done]: https://github.com/gulpjs/async-done [completions]: https://github.com/gulpjs/async-done#completion-and-error-resolution [downloads-image]: http://img.shields.io/npm/dm/bach.svg [npm-url]: https://www.npmjs.com/package/bach [npm-image]: http://img.shields.io/npm/v/bach.svg [travis-url]: https://travis-ci.org/gulpjs/bach [travis-image]: http://img.shields.io/travis/gulpjs/bach.svg?label=travis-ci [appveyor-url]: https://ci.appveyor.com/project/gulpjs/bach [appveyor-image]: https://img.shields.io/appveyor/ci/gulpjs/bach.svg?label=appveyor [coveralls-url]: https://coveralls.io/r/gulpjs/bach [coveralls-image]: http://img.shields.io/coveralls/gulpjs/bach.svg [gitter-url]: https://gitter.im/gulpjs/gulp [gitter-image]: https://badges.gitter.im/gulpjs/gulp.svg package/LICENSE000644 000765 000024 0000002142 12734334131011534 0ustar00000000 000000 The MIT License (MIT) Copyright (c) 2014 Blaine Bublitz, Eric Schoffstall and other contributors Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. package/index.js000644 000765 000024 0000000321 12734334130012170 0ustar00000000 000000 'use strict'; module.exports = { series: require('./lib/series'), parallel: require('./lib/parallel'), settleSeries: require('./lib/settleSeries'), settleParallel: require('./lib/settleParallel'), }; package/lib/helpers.js000644 000765 000024 0000003226 13140422505013274 0ustar00000000 000000 'use strict'; var assert = require('assert'); var filter = require('arr-filter'); var map = require('arr-map'); var flatten = require('arr-flatten'); var forEach = require('array-each'); function noop() {} function getExtensions(lastArg) { if (typeof lastArg !== 'function') { return lastArg; } } function filterSuccess(elem) { return elem.state === 'success'; } function filterError(elem) { return elem.state === 'error'; } function buildOnSettled(done) { if (typeof done !== 'function') { done = noop; } function onSettled(error, result) { if (error) { return done(error, null); } var settledErrors = filter(result, filterError); var settledResults = filter(result, filterSuccess); var errors = null; if (settledErrors.length) { errors = map(settledErrors, 'value'); } var results = null; if (settledResults.length) { results = map(settledResults, 'value'); } done(errors, results); } return onSettled; } function verifyArguments(args) { args = flatten(args); var lastIdx = args.length - 1; assert.ok(args.length, 'A set of functions to combine is required'); forEach(args, function(arg, argIdx) { var isFunction = typeof arg === 'function'; if (isFunction) { return; } if (argIdx === lastIdx) { // Last arg can be an object of extension points return; } var msg = 'Only functions can be combined, got ' + typeof arg + ' for argument ' + argIdx; assert.ok(isFunction, msg); }); return args; } module.exports = { getExtensions: getExtensions, onSettled: buildOnSettled, verifyArguments: verifyArguments, }; package/lib/parallel.js000644 000765 000024 0000001127 13140434261013426 0ustar00000000 000000 'use strict'; var initial = require('array-initial'); var last = require('array-last'); var asyncDone = require('async-done'); var nowAndLater = require('now-and-later'); var helpers = require('./helpers'); function iterator(fn, key, cb) { return asyncDone(fn, cb); } function buildParallel() { var args = helpers.verifyArguments(arguments); var extensions = helpers.getExtensions(last(args)); if (extensions) { args = initial(args); } function parallel(done) { nowAndLater.map(args, iterator, extensions, done); } return parallel; } module.exports = buildParallel; package/lib/series.js000644 000765 000024 0000001125 13140422453013122 0ustar00000000 000000 'use strict'; var initial = require('array-initial'); var last = require('array-last'); var asyncDone = require('async-done'); var nowAndLater = require('now-and-later'); var helpers = require('./helpers'); function iterator(fn, key, cb) { return asyncDone(fn, cb); } function buildSeries() { var args = helpers.verifyArguments(arguments); var extensions = helpers.getExtensions(last(args)); if (extensions) { args = initial(args); } function series(done) { nowAndLater.mapSeries(args, iterator, extensions, done); } return series; } module.exports = buildSeries; package/lib/settleParallel.js000644 000765 000024 0000001247 13140433760014615 0ustar00000000 000000 'use strict'; var initial = require('array-initial'); var last = require('array-last'); var asyncSettle = require('async-settle'); var nowAndLater = require('now-and-later'); var helpers = require('./helpers'); function iterator(fn, key, cb) { return asyncSettle(fn, cb); } function buildSettleParallel() { var args = helpers.verifyArguments(arguments); var extensions = helpers.getExtensions(last(args)); if (extensions) { args = initial(args); } function settleParallel(done) { var onSettled = helpers.onSettled(done); nowAndLater.map(args, iterator, extensions, onSettled); } return settleParallel; } module.exports = buildSettleParallel; package/lib/settleSeries.js000644 000765 000024 0000001245 13140433772014314 0ustar00000000 000000 'use strict'; var initial = require('array-initial'); var last = require('array-last'); var asyncSettle = require('async-settle'); var nowAndLater = require('now-and-later'); var helpers = require('./helpers'); function iterator(fn, key, cb) { return asyncSettle(fn, cb); } function buildSettleSeries() { var args = helpers.verifyArguments(arguments); var extensions = helpers.getExtensions(last(args)); if (extensions) { args = initial(args); } function settleSeries(done) { var onSettled = helpers.onSettled(done); nowAndLater.mapSeries(args, iterator, extensions, onSettled); } return settleSeries; } module.exports = buildSettleSeries;