old_contents: 'use strict'
  
  import gulp from 'gulp'
  import loadPlugins from 'gulp-load-plugins'
  import {Instrumenter} from 'isparta'
  import del from 'del'
  import seq from 'run-sequence'
  
  const DEST = 'lib'
  
  const $ = loadPlugins()
  
  const plumb = () => $.plumber({
    errorHandler: $.notify.onError('<%= error.message %>')
  })
  
  const test = () => {
    return gulp.src(['test/lib/setup.js', 'test/unit/**/*.js'], {read: false})
      .pipe($.mocha({reporter: 'dot'}))
  }
  
  gulp.task('clean', () => del(DEST))
  
  gulp.task('build', ['test'], () => {
    return gulp.src('src/**/*.js')
      .pipe(plumb())
      .pipe($.babel())
      .pipe(gulp.dest(DEST))
  })
  
  gulp.task('cleanbuild', (cb) => seq('clean', 'build', cb))
  
  gulp.task('coverage', (cb) => {
    gulp.src('src/**/*.js')
      .pipe($.istanbul({instrumenter: Instrumenter}))
      .pipe($.istanbul.hookRequire())
      .on('finish', () => test().pipe($.istanbul.writeReports()).on('end', cb))
  })
  
  gulp.task('coveralls', ['coverage'], () => {
    return gulp.src('coverage/lcov.info')
      .pipe($.coveralls())
  })
  
  gulp.task('test', test)
  
  gulp.task('watch', () => gulp.watch('{src,test}/**/*', ['cleanbuild']))
  
  gulp.task('default', ['cleanbuild'], () => gulp.start('watch'))
  
new_contents: 'use strict'
  
  import gulp from 'gulp'
  import loadPlugins from 'gulp-load-plugins'
  import {Instrumenter} from 'isparta'
  import del from 'del'
  import seq from 'run-sequence'
  
  const $ = loadPlugins()
  
  const plumb = () => $.plumber({
    errorHandler: $.notify.onError('<%= error.message %>')
  })
  
  const test = () => {
    return gulp.src(['test/lib/setup.js', 'test/unit/**/*.js'], {read: false})
      .pipe($.mocha({reporter: 'dot'}))
  }
  
  gulp.task('clean', () => del('lib'))
  
  gulp.task('build', ['test'], () => {
    return gulp.src('src/**/*.js')
      .pipe(plumb())
      .pipe($.babel())
      .pipe(gulp.dest('lib'))
  })
  
  gulp.task('cleanbuild', (cb) => seq('clean', 'build', cb))
  
  gulp.task('coverage', (cb) => {
    gulp.src('src/**/*.js')
      .pipe($.istanbul({instrumenter: Instrumenter}))
      .pipe($.istanbul.hookRequire())
      .on('finish', () => test().pipe($.istanbul.writeReports()).on('end', cb))
  })
  
  gulp.task('coveralls', ['coverage'], () => {
    return gulp.src('coverage/lcov.info')
      .pipe($.coveralls())
  })
  
  gulp.task('test', test)
  
  gulp.task('watch', () => gulp.watch('{src,test}/**/*', ['cleanbuild']))
  
  gulp.task('default', ['cleanbuild'], () => gulp.start('watch'))
  
subject: Remove constant for consistency