gulp scss workflow for styles and service worker w/ sw-precache

gulpfile.js

// Define dependencies
var gulp = require('gulp');
var sass = require('gulp-sass');
var autoprefixer = require('gulp-autoprefixer');
var nano = require('gulp-cssnano');
var parker = require('gulp-parker');
var run = require('gulp-run');
const workboxBuild = require('workbox-build');

// Compile sass to compressed css andd add vendor prefixes
gulp.task('styles', function() {
  gulp.src('src/scss/*.scss')
    .pipe(sass())
    .on('error', function(error) {
      console.log('\n ✖ ✖ ✖ ✖ ✖ ERROR ✖ ✖ ✖ ✖ ✖ \n \n' + error.message + '\n \n');
    })
    .pipe(autoprefixer({
      browsers: ['last 2 versions']
    }))
    .pipe(nano())
    .pipe(gulp.dest('../../project/static/css/'));
});

// CSS analysis tool
gulp.task('parker', function() {
  return gulp.src('../../project/static/css/project.css')
    .pipe(parker());
});

// Generate a Service Worker with sw-precache
gulp.task('generate-service-worker', function(callback) {
  var path = require('path');
  var swPrecache = require('./node_modules/sw-precache/lib/sw-precache');
  var rootDir = '../../project/static';

  swPrecache.write(path.join(rootDir, 'js/sw.js'), {
    cacheId: 'projectID',
    staticFileGlobs: [rootDir + '/**/*.{js,svg,css,png,jpg,gif,woff2}'],
    stripPrefix: rootDir,
    replacePrefix: '/project/static'
  }, callback);
});

// watching me, watching you
gulp.task('serve', ['styles','generate-service-worker'], function() {
  gulp.watch('src/scss/**/*.scss', ['styles']);
  gulp.watch('../../project/static/**/*.*', ['generate-service-worker']);
});

// default task
gulp.task('default', ['serve']);

package.json

{
  "name": "project",
  "version": "0.0.1",
  "description": "Project description",
  "main": "gulpfile.js",
  "author": "Your Name 2018",
  "license": "AGPL",
  "private": true,
  "devDependencies": {
    "gulp": "^3.9.1",
    "gulp-autoprefixer": "^5.0.0",
    "gulp-concat": "^2.6.0",
    "gulp-cssnano": "^2.1.2",
    "gulp-parker": "^0.1.4",
    "gulp-run": "^1.7.1",
    "gulp-sass": "^4.0.1",
    "gulp-uglify": "^3.0.1",
    "gulp-watch": "^5.0.1"
  },
  "dependencies": {
    "node-sass": "^4.9.0",
    "sw-precache": "^5.2.1"
  }
}