Gulp with Promises, take 1

gulpfile.js

var fs= require('when/node').liftAll(require('fs'))

var gulp= require('gulp'),
  when= require('when')

//// configuration registry ////

exports.resourceDir = 'resources'

//// util ////

function endStream(stream){
	var defer= when.defer()
	stream.once('end', function(){
		defer.resolve()
	})
	return defer.promise
}

//// resource fetching utils ////

function downloadUrlFile(file, dir){
	return (function download(){
		var download= require('gulp-download'),
		  filename= dir ? dir+'/'+file : file,
		  url= fs.readFile(filename+'.url', 'utf8'),
		  downloadStream= url.then(download).then(function(content){
			var stream= content.pipe(gulp.dest(filename))
			return endStream(stream)
		
		  })
		return downloadStream
	})
}

//// resource fetching ////

var downloadSchema= downloadUrlFile('all.json', 'resources')

gulp.task('resources-schema', downloadSchema)
gulp.task('resources', function(){
	return when.all([downloadSchema])
})