Browserify, watchify, exit with status 1 on uglify

gulpfile.js

'use strict'

var browserify = require('browserify')
var gulp = require('gulp')
var plumber = require('gulp-plumber')
var gutil = require('gulp-util')
var uglify = require('gulp-uglify')
var buffer = require('vinyl-buffer')
var source = require('vinyl-source-stream')
var watchify = require('watchify')

gulp.task('default', ['uglify'])

gulp.task('browserify', function () {
  return browserifyTask({debug: true})
})

gulp.task('watchify', function () {
  return browserifyTask({debug: true, watch: true, uglify: true})
})

gulp.task('uglify', function () {
  return browserifyTask({uglify: true})
})

function browserifyTask (params) {
  if (params == null) params = {}
  if (params.debug == null) params.debug = false
  if (params.watch == null) params.watch = false
  if (params.uglify == null) params.uglify = false

  var b = browserify({
    extensions: ['.js'],
    debug: params.debug
  })
  b.add('index.js')
  b.on('log', gutil.log)

  function bundle () {
    var stream = b.bundle()
      .pipe(source('index.js'))
      .pipe(buffer())
    if (params.debug === true) {
      stream = stream.pipe(plumber(errorHandler))
    }
    if (params.uglify === true) {
      stream = stream.pipe(uglify())
    }
    return stream.pipe(gulp.dest('./build'))
  }

  if (params.watch === true) {
    b = watchify(b)
    b.on('update', function () {
      gutil.log('Watchify detected a change')
      bundle()
    })
  }

  return bundle()
}

function errorHandler (err) {
  gutil.log(err.toString())
  this.emit('end')
}