ES6 project with Gulp, Sass, Babel & Browserify

gulpfile.js

/**
 * Created by Dmytro on 3/27/2016.
 */
var browserify = require('browserify'),
    gulp = require('gulp'),
    sourcemaps = require('gulp-sourcemaps'),
    sass = require('gulp-sass'),
    autoprefixer = require('gulp-autoprefixer'),
    source = require('vinyl-source-stream'),
    buffer = require('vinyl-buffer'),
    browserSync = require('browser-sync');

/* pathConfig*/
var entryPoint = './src/index.js',
    browserDir = './',
    sassWatchPath = './styles/**/*.scss',
    jsWatchPath = './src/**/*.js',
    htmlWatchPath = './**/*.html';
/**/

gulp.task('js', function () {
    return browserify(entryPoint, {debug: true, extensions: ['es6']})
        .transform("babelify", {presets: ["es2015"]})
        .bundle()
        .pipe(source('bundle.js'))
        .pipe(buffer())
        .pipe(sourcemaps.init({loadMaps: true}))
        .pipe(sourcemaps.write())
        .pipe(gulp.dest('./build/'))
        .pipe(browserSync.reload({stream: true}));
});

gulp.task('browser-sync', function () {
    const config = {
        server: {baseDir: browserDir}
    };

    return browserSync(config);
});

gulp.task('sass', function () {
  return gulp.src(sassWatchPath)
    .pipe(sourcemaps.init())
    .pipe(sass().on('error', sass.logError))
    .pipe(autoprefixer({
        browsers: ['last 2 versions']
    }))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest('./build/css'))
    .pipe(browserSync.reload({stream: true}));
});

gulp.task('watch', function () {
    gulp.watch(jsWatchPath, ['js']);
    gulp.watch(sassWatchPath, ['sass']);
    gulp.watch(htmlWatchPath, function () {
        return gulp.src('')
            .pipe(browserSync.reload({stream: true}))
    });
});

gulp.task('run', ['js', 'sass', 'watch', 'browser-sync']);

package.json

{
  "name": "ES6 with Gulp, Sass, Babel & Browserify",
  "version": "1.0.0",
  "description": "Gulpfile for ES6 project",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Dmytro Verbovyi",
  "devDependencies": {
    "babel-preset-es2015": "^6.6.0",
    "babelify": "^7.2.0",
    "browser-sync": "^2.11.2",
    "browserify": "^13.0.0",
    "gulp": "^3.9.1",
    "gulp-autoprefixer": "^3.1.0",
    "gulp-sass": "^2.2.0",
    "gulp-sourcemaps": "^1.6.0",
    "vinyl-buffer": "^1.0.0",
    "vinyl-source-stream": "^1.1.0"
  }
}