Gulp v4.0 task series

Hi there I am trying to use gulp 4.0 new feature gulp series. I have gulp functions I am trying to run in a series I also want to be able to call them individually. Both the coffee and vendor task call from a function which returns a promise.

The issue is it is not running a series it is executing coffee the vendor but also calling the allJs task which is the parrent

##
#  Return gulp destinations depending on params
#  FUTURE: This function will be resposible for
#  exectuing the transaltion scripts
#  @param {String} String representation of array of langs if anys
#  @return {promise} Reutrns a promise with a arrray
#  of destionations
##
getDest = (langs, path) ->
  return new Promise (resolve, reject) ->
    #Return default path if no lang specified or reject if no data
    resolve [gulp.dest(buildDir+path)] if !langs
    reject Error 'Empty language param' if typeof langs is Boolean

    str = langs.split(",")

    rtn = [] #Return array of destintion for each lang
    rtn.push gulp.dest("public/" + o + path) for o in str
    resolve rtn


##
#  Complie Vendor javascript files
#  @param {String} none
#  @return {Stream} stream
##
gulp.task 'coffee', (done) ->
  getDest(argv.lang, '/assets/js').then (response) ->
    gulp.src([coffeeSrc],{ base: 'assets' })
    .pipe(logger(
      before: 'Compiling CoffeeScript files ...'
      after: 'CoffeeScript files compiled successfully'
      showChange: silent))
    .pipe(coffee({bare: true}))
    .on('error', gutil.log)
    .on('error', gutil.beep)
    .pipe(uglify())
    .pipe(concat('app.min.js'))
    .pipe(multistream.apply(undefined, response))
    done()
  .catch (error) ->
    console.error 'failed', error
    done(err)



##
# Complie Vendor javascript files
# @param {String} none
# @return {Stream} stream
##
gulp.task 'vendor', (done) ->
  stream = getDest(argv.lang, '/assets/js').then (response) ->
    gulp.src(["./assets/jsv2/vendor/jquery.min.js",vendorSrc])
    .pipe(logger(
      before: 'Compiling vendor javascript files ...'
      after: 'Vendor javascript files compiled successfully'
      showChange: silent))
    .pipe(uglify())
    .pipe(concat('vendor.min.js'))
    .pipe(multistream.apply(undefined, response))
    done()
  .catch (error) ->
    console.error 'failed', error


##
#  Bundle all javascript files
#  @param {String} none
#  @return {Boolean} Finished
##
gulp.task 'allJs', gulp.series 'coffee', 'vendor', (done) ->
  getDest(argv.lang, '/assets/js').then (response) ->
    gulp.src(["./assets/jsv2/vendor/jquery.min.js",
      buildDir + '/**/**/vendor.min.js',
      buildDir + '/**/**/app.min.js'],{ base: 'assets' })
        .pipe(logger(
          before: 'Bundling javascript files ...'
          after: 'Bundled javascript files compiled successfully'
          showChange: silent))
        .pipe(uglify())
        .pipe(concat('all.min.js'))
        .pipe(multistream.apply(undefined, response))
        done()
  .catch (error) ->
    console.error 'failed', error
    done()

Im pretty new to promises and gulp. I just got Visual studio code which is great I was trying to use the debugger but just couldn't figure it, im still a pretty amateur debugger.

via Alex Kirwan