Gulpfile for Django (single app)

gulpfile.js

'use strict';

const DIST_DIR = 'gif/static';
const SRC_DIR = 'gif/static_src';
const MAPS_DIR = 'maps';

const JS_SRC = [
    'node_modules/angular/angular.js',
    'node_modules/angular-route/angular-route.js',
    'node_modules/angular-touch/angular-touch.js',
    'node_modules/angular-carousel/dist/angular-carousel.js',
    'node_modules/babel-polyfill/dist/polyfill.js'
];

const ES6_SRC = [
    SRC_DIR + '/*.js'
];

const LESS_SRC = [
    SRC_DIR + '/reset.less',
    SRC_DIR + '/fonts.less',
    'node_modules/angular-carousel/dist/angular-carousel.css',
    SRC_DIR + '/app.less'
];

const gulp = require('gulp');
const babel = require('gulp-babel');
const sourcemaps = require('gulp-sourcemaps');
const concat = require('gulp-concat');
const uglify = require('gulp-uglify');
const less = require('gulp-less');
const LessPluginCleanCSS = require('less-plugin-clean-css');
const LessPluginAutoPrefix = require('less-plugin-autoprefix');

const cleancss = new LessPluginCleanCSS({advanced: true});
const autoprefix = new LessPluginAutoPrefix({browsers: ["last 2 versions"]});


gulp.task('build:js', () => {
    return gulp.src(JS_SRC)
        .pipe(sourcemaps.init())
        .pipe(uglify())
        .pipe(concat('libs.js'))
        .pipe(sourcemaps.write(MAPS_DIR))
        .pipe(gulp.dest(DIST_DIR));
});


gulp.task('build:es6', () => {
    return gulp.src(ES6_SRC)
        .pipe(sourcemaps.init())
        .pipe(babel({
            presets: ['babel-preset-es2015']
        }))
        .pipe(uglify())
        .pipe(concat('script.js'))
        .pipe(sourcemaps.write(MAPS_DIR))
        .pipe(gulp.dest(DIST_DIR));
});


gulp.task('build:less', () => {
    return gulp.src(LESS_SRC)
        .pipe(sourcemaps.init())
        .pipe(less({
            plugins: [autoprefix, cleancss]
        }))
        .pipe(concat('style.css'))
        .pipe(sourcemaps.write(MAPS_DIR))
        .pipe(gulp.dest(DIST_DIR));
});


gulp.task('build:assets', [
    'build:js',
    'build:es6',
    'build:less'
]);


gulp.task('roll', ['build:assets'], () => {
    gulp.watch(JS_SRC, ['build:js']);
    gulp.watch(ES6_SRC, ['build:es6']);
    gulp.watch(LESS_SRC, ['build:less']);
});