pax_global_header00006660000000000000000000000064134361011160014506gustar00rootroot0000000000000052 comment=d0696e4be57337c5742ac6fe9d20892a2ab78b2e through2-3.0.1/000077500000000000000000000000001343610111600132515ustar00rootroot00000000000000through2-3.0.1/.gitignore000066400000000000000000000000311343610111600152330ustar00rootroot00000000000000node_modules .nyc_output through2-3.0.1/.jshintrc000066400000000000000000000021731343610111600151010ustar00rootroot00000000000000{ "predef": [ ] , "bitwise": false , "camelcase": false , "curly": false , "eqeqeq": false , "forin": false , "immed": false , "latedef": false , "noarg": true , "noempty": true , "nonew": true , "plusplus": false , "quotmark": true , "regexp": false , "undef": true , "unused": true , "strict": false , "trailing": true , "maxlen": 120 , "asi": true , "boss": true , "debug": true , "eqnull": true , "esnext": true , "evil": true , "expr": true , "funcscope": false , "globalstrict": false , "iterator": false , "lastsemic": true , "laxbreak": true , "laxcomma": true , "loopfunc": true , "multistr": false , "onecase": false , "proto": false , "regexdash": false , "scripturl": true , "smarttabs": false , "shadow": false , "sub": true , "supernew": false , "validthis": true , "browser": true , "couch": false , "devel": false , "dojo": false , "mootools": false , "node": true , "nonstandard": true , "prototypejs": false , "rhino": false , "worker": true , "wsh": false , "nomen": false , "onevar": false , "passfail": false }through2-3.0.1/.npmignore000066400000000000000000000000321343610111600152430ustar00rootroot00000000000000test .jshintrc .travis.ymlthrough2-3.0.1/.travis.yml000066400000000000000000000002051343610111600153570ustar00rootroot00000000000000language: node_js node_js: - '6' - '8' - '10' branches: only: - master notifications: email: - rod@vagg.org script: npm test through2-3.0.1/LICENSE.md000066400000000000000000000021501343610111600146530ustar00rootroot00000000000000# The MIT License (MIT) **Copyright (c) Rod Vagg (the "Original Author") and additional 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. through2-3.0.1/README.md000066400000000000000000000126041343610111600145330ustar00rootroot00000000000000# through2 [![NPM](https://nodei.co/npm/through2.png?downloads&downloadRank)](https://nodei.co/npm/through2/) **A tiny wrapper around Node.js streams.Transform (Streams2/3) to avoid explicit subclassing noise** Inspired by [Dominic Tarr](https://github.com/dominictarr)'s [through](https://github.com/dominictarr/through) in that it's so much easier to make a stream out of a function than it is to set up the prototype chain properly: `through(function (chunk) { ... })`. ***Note: Users of Node.js 0.10 and 0.12 should install `through2@2.x`. As of through2@3.x, readable-stream@3 is being used and is not compatible with older versions of Node.js.*** _v2.x support is being maintained on the [v2.x](https://github.com/rvagg/through2/tree/v2.x) branch._ ```js fs.createReadStream('ex.txt') .pipe(through2(function (chunk, enc, callback) { for (var i = 0; i < chunk.length; i++) if (chunk[i] == 97) chunk[i] = 122 // swap 'a' for 'z' this.push(chunk) callback() })) .pipe(fs.createWriteStream('out.txt')) .on('finish', () => doSomethingSpecial()) ``` Or object streams: ```js var all = [] fs.createReadStream('data.csv') .pipe(csv2()) .pipe(through2.obj(function (chunk, enc, callback) { var data = { name : chunk[0] , address : chunk[3] , phone : chunk[10] } this.push(data) callback() })) .on('data', (data) => { all.push(data) }) .on('end', () => { doSomethingSpecial(all) }) ``` Note that `through2.obj(fn)` is a convenience wrapper around `through2({ objectMode: true }, fn)`. ## API through2([ options, ] [ transformFunction ] [, flushFunction ]) Consult the **[stream.Transform](http://nodejs.org/docs/latest/api/stream.html#stream_class_stream_transform)** documentation for the exact rules of the `transformFunction` (i.e. `this._transform`) and the optional `flushFunction` (i.e. `this._flush`). ### options The options argument is optional and is passed straight through to `stream.Transform`. So you can use `objectMode:true` if you are processing non-binary streams (or just use `through2.obj()`). The `options` argument is first, unlike standard convention, because if I'm passing in an anonymous function then I'd prefer for the options argument to not get lost at the end of the call: ```js fs.createReadStream('/tmp/important.dat') .pipe(through2({ objectMode: true, allowHalfOpen: false }, (chunk, enc, cb) => { cb(null, 'wut?') // note we can use the second argument on the callback // to provide data as an alternative to this.push('wut?') } ) .pipe(fs.createWriteStream('/tmp/wut.txt')) ``` ### transformFunction The `transformFunction` must have the following signature: `function (chunk, encoding, callback) {}`. A minimal implementation should call the `callback` function to indicate that the transformation is done, even if that transformation means discarding the chunk. To queue a new chunk, call `this.push(chunk)`—this can be called as many times as required before the `callback()` if you have multiple pieces to send on. Alternatively, you may use `callback(err, chunk)` as shorthand for emitting a single chunk or an error. If you **do not provide a `transformFunction`** then you will get a simple pass-through stream. ### flushFunction The optional `flushFunction` is provided as the last argument (2nd or 3rd, depending on whether you've supplied options) is called just prior to the stream ending. Can be used to finish up any processing that may be in progress. ```js fs.createReadStream('/tmp/important.dat') .pipe(through2( (chunk, enc, cb) => cb(null, chunk), // transform is a noop function (cb) { // flush function this.push('tacking on an extra buffer to the end'); cb(); } )) .pipe(fs.createWriteStream('/tmp/wut.txt')); ``` through2.ctor([ options, ] transformFunction[, flushFunction ]) Instead of returning a `stream.Transform` instance, `through2.ctor()` returns a **constructor** for a custom Transform. This is useful when you want to use the same transform logic in multiple instances. ```js var FToC = through2.ctor({objectMode: true}, function (record, encoding, callback) { if (record.temp != null && record.unit == "F") { record.temp = ( ( record.temp - 32 ) * 5 ) / 9 record.unit = "C" } this.push(record) callback() }) // Create instances of FToC like so: var converter = new FToC() // Or: var converter = FToC() // Or specify/override options when you instantiate, if you prefer: var converter = FToC({objectMode: true}) ``` ## See Also - [through2-map](https://github.com/brycebaril/through2-map) - Array.prototype.map analog for streams. - [through2-filter](https://github.com/brycebaril/through2-filter) - Array.prototype.filter analog for streams. - [through2-reduce](https://github.com/brycebaril/through2-reduce) - Array.prototype.reduce analog for streams. - [through2-spy](https://github.com/brycebaril/through2-spy) - Wrapper for simple stream.PassThrough spies. - the [mississippi stream utility collection](https://github.com/maxogden/mississippi) includes `through2` as well as many more useful stream modules similar to this one ## License **through2** is Copyright (c) Rod Vagg and additional contributors and licensed under the MIT license. All rights not explicitly granted in the MIT license are reserved. See the included LICENSE file for more details. through2-3.0.1/package.json000066400000000000000000000013261343610111600155410ustar00rootroot00000000000000{ "name": "through2", "version": "3.0.1", "description": "A tiny wrapper around Node.js streams.Transform (Streams2/3) to avoid explicit subclassing noise", "main": "through2.js", "scripts": { "test": "nyc node test/test.js | faucet && nyc report" }, "repository": { "type": "git", "url": "https://github.com/rvagg/through2.git" }, "keywords": [ "stream", "streams2", "through", "transform" ], "author": "Rod Vagg (https://github.com/rvagg)", "license": "MIT", "dependencies": { "readable-stream": "2 || 3" }, "devDependencies": { "bl": "~2.0.1", "faucet": "0.0.1", "nyc": "~13.1.0", "stream-spigot": "~3.0.6", "tape": "~4.9.1" } } through2-3.0.1/test/000077500000000000000000000000001343610111600142305ustar00rootroot00000000000000through2-3.0.1/test/bench.js000066400000000000000000000016611343610111600156510ustar00rootroot00000000000000/* on rvagg@fletcher: @0.2.3: Ran 36719 iterations in 10000 ms */ const through2 = require('../') , bl = require('bl') , crypto = require('crypto') , assert = require('assert') function run (callback) { var bufs = Array.apply(null, Array(10)).map(function () { return crypto.randomBytes(32) }) , stream = through2(function (chunk, env, callback) { callback(null, chunk.toString('hex')) }) stream.pipe(bl(function (err, data) { assert(!err) assert.equal(data.toString(), Buffer.concat(bufs).toString('hex')) callback() })) bufs.forEach(function (b) { stream.write(b) }) stream.end() } var count = 0 , start = Date.now() ;(function exec () { count++ run(function () { if (Date.now() - start < 1000 * 10) { return setImmediate(exec) } console.log('Ran', count, 'iterations in', Date.now() - start, 'ms') }) }()) console.log('Running for ~10s')through2-3.0.1/test/test.js000066400000000000000000000201551343610111600155500ustar00rootroot00000000000000const test = require('tape') , through2 = require('../') , crypto = require('crypto') , bl = require('bl') , spigot = require('stream-spigot') test('plain through', function (t) { var th2 = through2(function (chunk, enc, callback) { if (!this._i) this._i = 97 // 'a' else this._i++ var b = Buffer.alloc(chunk.length) for (var i = 0; i < chunk.length; i++) b[i] = this._i this.push(b) callback() }) th2.pipe(bl(function (err, b) { var s = b.toString('ascii') t.equal('aaaaaaaaaabbbbbcccccccccc', s, 'got transformed string') t.end() })) th2.write(crypto.randomBytes(10)) th2.write(crypto.randomBytes(5)) th2.write(crypto.randomBytes(10)) th2.end() }) test('pipeable through', function (t) { var th2 = through2(function (chunk, enc, callback) { if (!this._i) this._i = 97 // 'a' else this._i++ var b = Buffer.alloc(chunk.length) for (var i = 0; i < chunk.length; i++) b[i] = this._i this.push(b) callback() }) th2.pipe(bl(function (err, b) { var s = b.toString('ascii') // bl() acts like a proper streams2 stream and passes as much as it's // asked for, so we really only get one write with such a small amount // of data t.equal(s, 'aaaaaaaaaaaaaaaaaaaaaaaaa', 'got transformed string') t.end() })) var bufs = bl() bufs.append(crypto.randomBytes(10)) bufs.append(crypto.randomBytes(5)) bufs.append(crypto.randomBytes(10)) bufs.pipe(th2) }) test('object through', function (t) { t.plan(3) var th2 = through2({ objectMode: true}, function (chunk, enc, callback) { this.push({ out: chunk.in + 1 }) callback() }) var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('object through with through2.obj', function (t) { t.plan(3) var th2 = through2.obj(function (chunk, enc, callback) { this.push({ out: chunk.in + 1 }) callback() }) var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('flushing through', function (t) { var th2 = through2(function (chunk, enc, callback) { if (!this._i) this._i = 97 // 'a' else this._i++ var b = Buffer.alloc(chunk.length) for (var i = 0; i < chunk.length; i++) b[i] = this._i this.push(b) callback() }, function (callback) { this.push(Buffer.from([ 101, 110, 100 ])) callback() }) th2.pipe(bl(function (err, b) { var s = b.toString('ascii') t.equal(s, 'aaaaaaaaaabbbbbccccccccccend', 'got transformed string') t.end() })) th2.write(crypto.randomBytes(10)) th2.write(crypto.randomBytes(5)) th2.write(crypto.randomBytes(10)) th2.end() }) test('plain through ctor', function (t) { var Th2 = through2.ctor(function (chunk, enc, callback) { if (!this._i) this._i = 97 // 'a' else this._i++ var b = Buffer.alloc(chunk.length) for (var i = 0; i < chunk.length; i++) b[i] = this._i this.push(b) callback() }) var th2 = new Th2() th2.pipe(bl(function (err, b) { var s = b.toString('ascii') t.equal('aaaaaaaaaabbbbbcccccccccc', s, 'got transformed string') t.end() })) th2.write(crypto.randomBytes(10)) th2.write(crypto.randomBytes(5)) th2.write(crypto.randomBytes(10)) th2.end() }) test('reuse through ctor', function (t) { t.plan(4) var Th2 = through2.ctor(function (chunk, enc, callback) { if (!this._i) { t.ok(1, 'did not contain previous instance data (this._i)') this._i = 97 // 'a' } else this._i++ var b = Buffer.alloc(chunk.length) for (var i = 0; i < chunk.length; i++) b[i] = this._i this.push(b) callback() }) var th2 = Th2() th2.pipe(bl(function (err, b) { var s = b.toString('ascii') t.equal('aaaaaaaaaabbbbbcccccccccc', s, 'got transformed string') var newInstance = Th2() newInstance.pipe(bl(function (err, b) { var s = b.toString('ascii') t.equal('aaaaaaabbbbccccccc', s, 'got transformed string') })) newInstance.write(crypto.randomBytes(7)) newInstance.write(crypto.randomBytes(4)) newInstance.write(crypto.randomBytes(7)) newInstance.end() })) th2.write(crypto.randomBytes(10)) th2.write(crypto.randomBytes(5)) th2.write(crypto.randomBytes(10)) th2.end() }) test('object through ctor', function (t) { t.plan(3) var Th2 = through2.ctor({ objectMode: true}, function (chunk, enc, callback) { this.push({ out: chunk.in + 1 }) callback() }) var th2 = new Th2() var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('pipeable object through ctor', function (t) { t.plan(4) var Th2 = through2.ctor({ objectMode: true}, function (record, enc, callback) { if (record.temp != null && record.unit == 'F') { record.temp = ( ( record.temp - 32 ) * 5 ) / 9 record.unit = 'C' } this.push(record) callback() }) var th2 = Th2() var expect = [-19, -40, 100, 22] th2.on('data', function (o) { t.deepEqual(o, { temp: expect.shift(), unit: 'C' }, 'got transformed object') }) spigot({objectMode: true}, [ {temp: -2.2, unit: 'F'}, {temp: -40, unit: 'F'}, {temp: 212, unit: 'F'}, {temp: 22, unit: 'C'} ]).pipe(th2) }) test('object through ctor override', function (t) { t.plan(3) var Th2 = through2.ctor(function (chunk, enc, callback) { this.push({ out: chunk.in + 1 }) callback() }) var th2 = Th2({objectMode: true}) var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('object settings available in transform', function (t) { t.plan(6) var Th2 = through2.ctor({objectMode: true, peek: true}, function (chunk, enc, callback) { t.ok(this.options.peek, "reading options from inside _transform") this.push({ out: chunk.in + 1 }) callback() }) var th2 = Th2() var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('object settings available in transform override', function (t) { t.plan(6) var Th2 = through2.ctor(function (chunk, enc, callback) { t.ok(this.options.peek, "reading options from inside _transform") this.push({ out: chunk.in + 1 }) callback() }) var th2 = Th2({objectMode: true, peek: true}) var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('object override extends options', function (t) { t.plan(6) var Th2 = through2.ctor({objectMode: true}, function (chunk, enc, callback) { t.ok(this.options.peek, "reading options from inside _transform") this.push({ out: chunk.in + 1 }) callback() }) var th2 = Th2({peek: true}) var e = 0 th2.on('data', function (o) { t.deepEqual(o, { out: e === 0 ? 102 : e == 1 ? 203 : -99 }, 'got transformed object') e++ }) th2.write({ in: 101 }) th2.write({ in: 202 }) th2.write({ in: -100 }) th2.end() }) test('can be destroyed', function(t) { t.plan(1) var th = through2() th.on('close', function() { t.ok(true, 'shoud emit close') t.end() }) th.destroy() }) test('can be destroyed twice', function(t) { t.plan(1) var th = through2() th.on('close', function() { t.ok(true, 'shoud emit close') t.end() }) th.destroy() th.destroy() }) through2-3.0.1/through2.js000066400000000000000000000041171343610111600153540ustar00rootroot00000000000000var Transform = require('readable-stream').Transform , inherits = require('util').inherits function DestroyableTransform(opts) { Transform.call(this, opts) this._destroyed = false } inherits(DestroyableTransform, Transform) DestroyableTransform.prototype.destroy = function(err) { if (this._destroyed) return this._destroyed = true var self = this process.nextTick(function() { if (err) self.emit('error', err) self.emit('close') }) } // a noop _transform function function noop (chunk, enc, callback) { callback(null, chunk) } // create a new export function, used by both the main export and // the .ctor export, contains common logic for dealing with arguments function through2 (construct) { return function (options, transform, flush) { if (typeof options == 'function') { flush = transform transform = options options = {} } if (typeof transform != 'function') transform = noop if (typeof flush != 'function') flush = null return construct(options, transform, flush) } } // main export, just make me a transform stream! module.exports = through2(function (options, transform, flush) { var t2 = new DestroyableTransform(options) t2._transform = transform if (flush) t2._flush = flush return t2 }) // make me a reusable prototype that I can `new`, or implicitly `new` // with a constructor call module.exports.ctor = through2(function (options, transform, flush) { function Through2 (override) { if (!(this instanceof Through2)) return new Through2(override) this.options = Object.assign({}, options, override) DestroyableTransform.call(this, this.options) } inherits(Through2, DestroyableTransform) Through2.prototype._transform = transform if (flush) Through2.prototype._flush = flush return Through2 }) module.exports.obj = through2(function (options, transform, flush) { var t2 = new DestroyableTransform(Object.assign({ objectMode: true, highWaterMark: 16 }, options)) t2._transform = transform if (flush) t2._flush = flush return t2 })