promise-spawner

Lazy nodejs spawner with stdout/stderr streams and error handling through promises

Examples

Basic command example

var spawner = new Spawner()
 
spawner
    .spawn('echo hello', 'echo world')
    .then(function({code: code, data: data}) {
        expect(code).to.equal(0)
        //to access out/err datas use
        console.log(data.out, data.err)
        //with this example, this.data.out will look like this:
        expect(data.out).to.eql(['hello', 'world'])
    })

Basic failing command example

var spawner = new Spawner()
 
spawner
    .spawn('exit 1', 'this will not be executed!')
    .catch(function({code}) {
        console.log('Script failed with code ', code)
    })

Modifiers and streaming

var modifiers = {
    out: function(d) { return d },
    err: 'this is an error: '
}
 
var spawner = new Spawner(modifiers)
 
//spawner gives you global streams from spawned stdout and stderr
spawner.out.pipe(process.stdout)
spawner.err.pipe(process.stdout)
 
spawner
    //this will print "hello\n world\n err\n done\n" to the stdout
    .spawn(['echo hello', 'echo world'], 'echo err >&2', ['sleep 0', 'echo done && exit 0'])
    .then(function({code, data}) {
            //see below
        expect(data.err[0]).to.equal('err')
 
        return spawner.spawn('echo next')
    })
    .then(function({code, data}) {
        expect(data.out[0]).to.equal('next')
    })
 

Add options on the fly

var previous = require('path').resolve(__dirname, '../')
var s = spawner.sp('echo $(pwd)"/$SP"', {env: {SP: 'test'}, cwd: previous})
 
s.then(function({code, data}) {
  expect(data.out[0]).to.equal(__dirname)
})

Every data streamed from the spawn running script is pushed in an array that is accessible through data. This object contains two arrays : {err: Array, out: Array}. It is intendend to check stdout/stderr results when the script has run. To get better control, use streams!

API

Spawner([options], [spawn_options])

• options: modifiers: {out: Function|String, err: Function|String}
• spawn_options (optional): http://nodejs.org/api/child_process.html
• returns an object:
  • spawn: spawn a command
  • sp: shortcut to spawn
  • out: global out stream
  • err: global err stream

spawner.spawn(...commands, [spawn_options]) or spawner.sp(...commands, [spawn_options])

• command can be an Array or a String
• spawn_options (optional): http://nodejs.org/api/child_process.html

Take a look at the https://github.com/soyuka/promise-spawner/blob/master/test/index.js

Licence

The MIT License (MIT)

Copyright (c) 2014 soyuka

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.