gulpfile.js

var gulp = require('gulp')
var browserify = require('browserify')
var babelify = require('babelify')
var source = require('vinyl-source-stream')
var browserSync = require('browser-sync')

gulp.task('scripts', function() {
  browserify('src/scripts/main.js')
    .transform(babelify.configure({
      presets: ['es2015', 'react'],
      plugins: [
        'transform-strict-mode',
        'array-includes',
        'transform-class-properties'
      ]
    }))
    .bundle()
    .pipe(source('bundle.js'))
    .pipe(gulp.dest('dist/scripts'))
    .pipe(browserSync.reload({ stream: true, once: true }))
})

gulp.task('watch', function() {
  gulp.watch('src/scripts/**/*.*', ['scripts'])
})

gulp.task('sync', function() {
  browserSync({
    server: '.'
  })
})

gulp.task('default', ['watch', 'scripts', 'sync'])