exec as Promise(d)

Runs Node.js' exec asynchronously, optionally logging and reporting non-empty stderr content.

Usage

exec = require('exec-as-promised')()

Then exec(command,[options],[fail_if_stderr]) where options is the same as in child_process.exec, and fail_if_stderr is a boolean indicating whether to reject if stderr is not empty.

exec('/bin/date')
.then( function (stdout) {
  console.log(date);
}

module.exports = ->
  (cmd,args...) ->
    fail_if_stderr = false
    options = {}
    for arg in args
      switch typeof arg
        when 'boolean'
          fail_if_stderr = arg
        when 'object'
          options = arg
        else
          throw new Error "Invalid #{typeof arg} argument"

    debug "Executing", {cmd, options}
    _exec cmd, options
    .then ([stdout,stderr]) ->
      debug 'Command returned', {cmd,stdout,stderr}
      if stderr and fail_if_stderr
        Promise.reject new Error stderr
      else
        stdout
    .catch (error) ->
      debug "#{cmd} failed: #{error}"
      Promise.reject error

Promise = require 'bluebird'
_exec = Promise.promisify (require 'child_process').exec, multiArgs:true
pkg = require './package'
debug = (require 'debug') pkg.name